JMS providers like ActiveMQ are based on the concept of passing one-directional messages between nodes and brokers asynchronously. A thorough knowledge of the type of messages that can be sent through a JMS middleware can simplify a lot your work in mapping the communication patterns to real code. The basic Message interface Some object members are shared by all messages: header fields, used to identify univocally a message and to route it to the right brokers and consumers. A dynamic map of properties which can be read programmatically by JMS brokers in order to filter or to route messages. A body, which is differentiated in the various implementations we'll see. Header fields The set of getJMS*() methods on the Message interface defines the available headers. Two of them are oriented to message identification: getJMSMessageID() contains a generated ID for identifying a message, unique at least for the current broker. All generated IDs start with the prefix 'ID:', but you can override it with the corresponding setter. getJMSCorrelationID() (and getJMSCorrelationID() as bytes) can link a message with another, usually one that has been sent previously. For example, a reply can carry the ID of the original message when put in another queue. Two to sender and recipient identification: getJMSDestination() returns a Destination object (a Topic or a Queue, or their temporary version) describing where the message was directed. getJMSReplyTo() is a Destination object where replies should be sent; it can be null of course. Three tune the delivery mechanism: getJMSDeliveryMode() can be DeliveryMode.NON_PERSISTENT or DeliveryMode.PERSISTENT; only persistent messages guarantee delivery in case of a crash of the brokers that transport it. getJMSExpiration() returns a timestamp indicating the expiration time of the message; it can be 0 on a message without a defined expiration. getJMSPriority() returns a 0-9 integer value (higher is better) defining the priority for delivery. It is only a best-effort value. While the remaining ones contain metadata: getJMSRedelivered() returns a boolean indicating if the message is being delivered again after a delivery which was not acknowledge. getJMSTimestamp() returns a long indicating the time of sending. getJMSType() defines a field for provider-specific or application-specific message types. Of these headers, only JMSCorrelationID, JMSReplyTo and JMSType have to be set when needed. The others are generated or managed by the send() and publish() methods if not specified (there are setters available for each of these headers.) Properties Generic properties with a String name can be added to messages and read with getBooleanProperty(), getStringProperty() and similar methods. The corresponding setters setBooleanProperty(), setStringProperty(), ... can be used for their addition. The reason for keeping some properties out of the content of the message (which a MapMessage can contain) is so they could be read before reaching the destination, for example in a JMS broker. The use case for this access to message properties is routing and filtering: downstream brokers and consumers may define a filter such as "I am interested only on messages on this Topic that have property X = 'value' and Y = 'value2'". Bodies All the subinterfaces of javax.jms.Message defined by the API provide different types of message bodies (while actual classes are defined by the providers and are not part of the API). Actual instantiation is then handled by the Session, which implements an Abstract Factory pattern. On the receival side, a cast is necessary for any message type (at least in the Java JMS Api), since only a generic Message is read. BytesMessage is the most basic type: it contains a sequence of uninterpreted bytes. Hence, it can in theory contain anything, but the generation and interpretation of the content is the client's job. BytesMessage m = session.createBytesMessage(); m.writeByte(65); m.writeBytes(new byte[] { 66, 68, 70 }); // on receival (cast shown only here) BytesMessage m = (BytesMessage) genericMessage; byte[] content = new byte[4]; m.readBytes(content); MapMessage defines a message containing an (unordered) set of key/value pairs, also called a map or dictionary or hash. However, the keys are String objects, while the values are primitives or Strings; since they are primitives, they shouldn't be null. MapMessage = session.createMapMessage(); m.setString('key', 'value'); // or m.setObject('key', 'value') to avoid specifying a type // on receival m.getString('key'); // or m.getObject('key') ObjectMessage wraps a generic Object for transmission. The Object should be Serializable. ObjectMessage m = session.createObjectMessage(); m.setObject(new ValueObject('field1', 42)); // on receival ValueObject vo = (ValueObject) m.getObject(); StreamMessage wraps a stream of primitive values of indefinite length. StreamMessage m = session.createStreamMessage(); m.writeBoolean(true); m.writeBoolean(false); m.writeBoolean(true); // receival System.out.println(m.readBoolean()); System.out.println(m.readBoolean()); System.out.println(m.readBoolean()); // prints true, false, true TextMessage wraps a String of any length. TextMessage m = session.createTextMessage("Contents"); // or use m.setText() afterwards // receival String text = m.getText(); Usually all messages are in a read-only phase after receival, so only getters can be called on them.

My prefered solution was to use the Maven ‘update snapshots’ command line argument.

I solved a little problem last night when playing with named pipes. I created a named pipe that writes all output to a file. Named pipes are opened for all users on a single machine. In this post I will show you a simple class that works as a pipe server. In .NET-based languages we can use the System.IO.Pipes namespace classes to work with named pipes. Here is my simple pipe server that writes all client output to file. public class MyPipeServer { public void Run() { var sid = new SecurityIdentifier(WellKnownSidType.WorldSid, null); var rule = new PipeAccessRule(sid, PipeAccessRights.ReadWrite, AccessControlType.Allow); var sec = new PipeSecurity(); sec.AddAccessRule(rule); using (NamedPipeServerStream pipeServer = new NamedPipeServerStream ("testpipe",PipeDirection.InOut, 100, PipeTransmissionMode.Byte, PipeOptions.None, 0, 0, sec)) { pipeServer.WaitForConnection(); var read = 0; var bytes = new byte[4096]; using(var file=File.Open(@"c:\tmp\myfile.dat", FileMode.Create)) while ((read = pipeServer.Read(bytes, 0, bytes.Length)) > 0) { file.Write(bytes, 0, read); file.Flush(); } } } } Real-life pipe scenarios are usually more complex but this simple class is good to get things running like they should be.

Use short enough and long enough variable names in each scope of code. Generally length may be 1 char for loop counters, 1 word for condition/loop variables, 1-2 words for methods, 2-3 words for classes, 3-4 words for globals. Use specific names for variables, for example "value", "equals", "data", ... are not valid names for any case. Use meaningful names for variables. Variable name must define the exact explanation of its content. Don't start variables with o_, obj_, m_ etc. A variable does not need tags which states it is a variable. Obey company naming standards and write variable names consistently in application: e.g. txtUserName, lblUserName, cmbSchoolType, ... Otherwise readability will reduce and find/replace tools will be unusable. Obey programming language standards and don't use lowercase/uppercase characters inconsistently: e.g. userName, UserName, USER_NAME, m_userName, username, ... use Camel Case (aka Upper Camel Case) for classes: VelocityResponseWriter use Lower Case for packages: com.company.project.ui use Mixed Case (aka Lower Camel Case) for variables: studentName use Upper Case for constants : MAX_PARAMETER_COUNT = 100 use Camel Case for enum class names and Upper Case for enum values. don't use '_' anywhere except constants and enum values (which are constants). For example for Java, Don't reuse same variable name in the same class in different contexts: e.g. in method, constructor, class. So you can provide more simplicity for understandability and maintainability. Don't use same variable for different purposes in a method, conditional etc. Create a new and different named variable instead. This is also important for maintainability and readability. Don't use non-ASCII chars in variable names. Those may run on your platform but may not on others. Don't use too long variable names (e.g. 50 chars). Long names will bring ugly and hard-to-read code, also may not run on some compilers because of character limit. Decide and use one natural language for naming, e.g. using mixed English and German names will be inconsistent and unreadable. Use meaningful names for methods. The name must specify the exact action of the method and for most cases must start with a verb. (e.g. createPasswordHash) Obey company naming standards and write method names consistently in application: e.g. getTxtUserName(), getLblUserName(), isStudentApproved(), ... Otherwise readability will reduce and find/replace tools will be unusable. Obey programming language standards and don't use lowercase/uppercase characters inconsistently: e.g. getUserName, GetUserName, getusername, ... For example for Java, use Mixed Case for method names: getStudentSchoolType use Mixed Case for method parameters: setSchoolName(String schoolName) Use meaningful names for method parameters, so it can documentate itself in case of no documentation.

The HTML 5 specification is full of definitions of new events, but it gathers them in a long list only divided by the category of support: some must be supported by all elements, some by window and derivatives, and so on. Unfortunately this style mixes up many different kinds of events, like the multimedia (canplay) and keyboard-based ones (keyup). In this article, I have collected all events that can be generated with a mouse. In HTML 4 There are a few well-supported events ported by the previous version of the specification. Everyone would expect a browser to correctly fire these events: click: the simplest event. dblclick: fired on a double click on an HTML element. mousedown: fired when the button is pressed. mouseup: fired when the button is released. mouseover: fired when the cursor passes over an HTML element. mouseout: fired when the cursor leaves the displaying area of an HTML element; the inverse of mouseover. mousemove: fired everytime the cursor moves one pixel. It's very easy to hang the browser by targeting this event. In any case, window.addEventListener and element.addEventListener (where element is a reference to a DOM element) are the functions to call to setup event handlers. You could also use the on$eventName HTML attribute or property (e.g. onclick, onmouseover), but addEventListener is more flexible as it allows for many different listeners to work on the same event, without one silently replacing the other. HTML 5: dragging Most of the new mouse events (but not necessarily the most interesting ones) deal with drag and drop support: drag: fired frequently on a dragged element (which must define the *draggable* attribute.) dragstart: fired when the mouse is held down on an element and the movement starts. dragend: fired when the element is released. dragenter: fired when an element enters the displayed area of another one. dragleave: fired when an element exits the displayed area, as the inverse of dragenter. dragover: fired frequently when an element is over another. drop: fired when an element is released over another. drag, dragstart, and dragend are fired on the dragged element, while dragenter, dragleave, dragover and drop are fired on the target one. Here is a self-contained example of their usage: One of the common usages of the Drag and Drop API is the integration with the File API to allow for upload of files by dragging into the browser's window. HTML 5: the wheel The mousewheel event is fired upon the usage of the wheel over an element or the window. Here is an example that zooms in or out of an HTML element by modifying its size: The scroll event instead works at an higher-level of abstraction: it is not really a mouse-specific event, as it can be generated by the mouse but also by pressing scrolling keys. What the event models is a change in the visible section of an element, generated by a movement in the vertical or horizontal scrollbars: Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... Lorem ipsum dolor amet... HTML 5: right click The contextmenu event is fired upon a right click, that opens a contextual menu centered on the mouse pointer. Here is an example of interception: If you want to display an alternate contextual menu, you would also probably want to cancel the event; however, many browsers allow the user to override these manipulations and always show the original menu (think of websites hiding the View Source entry).

In a recent project, I had a requirement of connecting to multiple databases using hibernate. As tapestry-hibernate module does not provide an out-of-box support, I thought of adding one. https://github.com/tawus/tapestry5 Now that the application is in production, I thought of writing a simple “How to”. I have cloned the latest stable(5.3.2) tapestry project at https://github.com/tawus/tapestry5 and have added multiple database support to it. Single Database It is almost fully compatible with the previous integration when using a single database except for a few things 1) HibernateConfigurer has changed public interface HibernateConfigurer { /** * Passed the configuration so as to make changes. */ void configure(Configuration configuration); /** * Factory Id for which this configurer is meant for */ Class getMarker(); /** * Entity package names * * @return */ String[] getPackageNames(); } 2) There is no HibernateEntityPackageManager, as the packages can be contributed by adding more HibernateConfigurers with the same Markers. Multiple databases For multiple database, a marker has to be used for accessing Session or HibernateSessionManager @Inject @XDB private Session session; @Inject @YDB private HibernateSessionManager sessionManager; @XDB @CommitAfter void myMethod(){ } Also you have to define a HibernateSessionManager and a Session for the secondary database in the Module class. @Scope(ScopeConstants.PERTHREAD) @Marker(DatabaseTwo.class) public static HibernateSessionManager buildHibernateSessionManagerForFinacle( HibernateSessionSource sessionSource, PerthreadManager perthreadManager) { HibernateSessionManagerImpl service = new HibernateSessionManagerImpl(sessionSource, DatabaseTwo.class); perthreadManager.addThreadCleanupListener(service); return service; } @Marker(DatabaseTwo.class) public static Session buildSessionForFinacle( @Local HibernateSessionManager sessionManager, PropertyShadowBuilder propertyShadowBuilder) { return propertyShadowBuilder.build(sessionManager, "session", Session.class); } Notice an annotation @DatabaseTwo.class. This is a Factory marker and is used to identify a service related to a particular SessionFactory. @Retention(RetentionPolicy.RUNTIME) @Target( {ElementType.FIELD, ElementType.PARAMETER, ElementType.METHOD}) @FactoryMarker @Documented public @interface DatabaseTwo { } A typical AppModule for two databases will be public class AppModule { public static void bind(ServiceBinder binder) { binder.bind(DemoService.class, DemoServiceImpl.class); } @Contribute(HibernateSessionSource.class) public static void configureHibernateSources(OrderedConfiguration configurers) { configurers.add("databaseOne", new HibernateConfigurer() { public void configure(org.hibernate.cfg.Configuration configuration) { configuration.configure("/databaseOne.xml"); } public Class getMarker() { return DefaultFactory.class; } public String[] getPackageNames() { return new String[] {"org.example.demo.one"}; } }); configurers.add("databaseTwo", new HibernateConfigurer() { public void configure(org.hibernate.cfg.Configuration configuration) { configuration.configure("/databaseTwo.xml"); } public Class getMarker() { return DatabaseTwo.class; } public String[] getPackageNames() { return new String[] {"org.example.demo.two"}; } }); } @Contribute(SymbolProvider.class) @ApplicationDefaults public static void addSymbols(MappedConfiguration configuration) { configuration.add(HibernateSymbols.DEFAULT_CONFIGURATION, "false"); configuration.add("tapestry.app-package", "org.example.demo"); } @Scope(ScopeConstants.PERTHREAD) @Marker(DatabaseTwo.class) public static HibernateSessionManager buildHibernateSessionManagerForFinacle( HibernateSessionSource sessionSource, PerthreadManager perthreadManager) { HibernateSessionManagerImpl service = new HibernateSessionManagerImpl(sessionSource, DatabaseTwo.class); perthreadManager.addThreadCleanupListener(service); return service; } @Marker(DatabaseTwo.class) public static Session buildSessionForFinacle( @Local HibernateSessionManager sessionManager, PropertyShadowBuilder propertyShadowBuilder) { return propertyShadowBuilder.build(sessionManager, "session", Session.class); } } Injecting into Services You can inject a session in a service using the marker. As DatabaseOne is being used as the default configuration, in order to inject its Session, you have to annotate it with @DefaultFactory. For DatabaseTwo, you can use @DatabaseTwo annotation. public class DemoServiceImpl implements DemoService { private Session sessionOne; private Session sessionTwo; public DemoServiceImpl( @DefaultFactory Session sessionOne, @DatabaseTwo Session sessionTwo) { this.sessionOne = sessionOne; this.sessionTwo = sessionTwo; } @SuppressWarnings("unchecked") public List listOnes() { return sessionOne.createCriteria(EntityOne.class).list(); } @SuppressWarnings("unchecked") public List listTwos() { return sessionTwo.createCriteria(EntityTwo.class).list(); } public void save(EntityOne entityOne) { sessionOne.saveOrUpdate(entityOne); } public void save(EntityTwo entityTwo) { sessionTwo.saveOrUpdate(entityTwo); } } Using @CommitAfter You can add an advice the same way you used to. The only change is in @CommitAfter. You have to additionally annotate the method with the respective marker. public interface DemoService { List listOnes(); List listTwos(); @CommitAfter @DefaultFactory void save(EntityOne entityOne); @CommitAfter @DatabaseTwo void save(EntityTwo entityTwo); } Here is an example. From http://tawus.wordpress.com/2012/03/03/tapestry-hibernate-multiple-databases/

The JavaFX 2 class javafx.scene.paint.Color includes several fields that are static Color members. I have taken advantage of the convenience of these publicly available static fields in many of my JavaFX 2 examples shown in this blog. There is a lengthy list of these predefined Color fields ranging (in alphabetical order) from Color.ALICEBLUE to Color.YELLOWGREEN. I have sometimes thought it would be nice to quickly see what some of the less obvious colors look like and the simple JavaFX 2 application featured in this post provides a sampling of those colors. The sample JavaFX 2 application shown here uses simple Java reflection to introspect the JavaFX Color class for its public fields that themselves of type Color. The application then iterates over those public fields, providing information about each color such as the color's field name, a sample of the color, and the red/green/blue components of that color. The final row allows the user to specify red/green/blue values to see how such a color is rendered. This is useful if the user sees a standard color that is close to what he or she wants and the user wants to try adjusting it slightly. To ensure meaningful values for displaying a color based on provided red/green/blue values, the application ensures that entered values are treated as doubles between 0.0 and 1.0 even if they are not numbers or are numbers outside of that range. The simple JavaFX 2 application showing standard Color fields is shown in the next code listing. JavaFxColorDemo.java package dustin.examples; import static java.lang.System.err; import java.lang.reflect.Field; import javafx.application.Application; import javafx.event.EventHandler; import javafx.scene.Group; import javafx.scene.Scene; import javafx.scene.control.*; import javafx.scene.input.MouseEvent; import javafx.scene.layout.HBox; import javafx.scene.layout.Pane; import javafx.scene.layout.VBox; import javafx.scene.paint.Color; import javafx.scene.shape.Rectangle; import javafx.scene.shape.RectangleBuilder; import javafx.stage.Stage; /** * Simple JavaFX 2 application that prints out values of standardly available * Color fields. * * @author Dustin */ public class JavaFxColorDemo extends Application { /** Width of label for colorn name. */ private final static int COLOR_NAME_WIDTH = 150; /** Width of rectangle that displays color. */ private final static int COLOR_RECT_WIDTH = 50; /** Height of rectangle that displays color. */ private final static int COLOR_RECT_HEIGHT = 25; private final TextField redField = TextFieldBuilder.create() .text("Red Value").build(); private final TextField greenField = TextFieldBuilder.create() .text("Green Value").build(); private final TextField blueField = TextFieldBuilder.create() .text("Blue Value").build(); private final Rectangle customColorRectangle = RectangleBuilder.create() .width(COLOR_RECT_WIDTH).height(COLOR_RECT_HEIGHT) .fill(Color.WHITE).stroke(Color.BLACK).build(); /** * Build a pane containing details about the instance of Color provided. * * @param color Instance of Color about which generated Pane should describe. * @return Pane representing information on provided Color instance. */ private Pane buildColorBox(final Color color, final String colorName) { final HBox colorBox = new HBox(); final Label colorNameLabel = new Label(colorName); colorNameLabel.setMinWidth(COLOR_NAME_WIDTH); colorBox.getChildren().add(colorNameLabel); final Rectangle colorRectangle = new Rectangle(COLOR_RECT_WIDTH, COLOR_RECT_HEIGHT); colorRectangle.setFill(color); colorRectangle.setStroke(Color.BLACK); colorBox.getChildren().add(colorRectangle); final String rgbString = String.valueOf(color.getRed()) + " / " + String.valueOf(color.getGreen()) + " / " + String.valueOf(color.getBlue()) + " // " + String.valueOf(color.getOpacity()); final Label rgbLabel = new Label(rgbString); rgbLabel.setTooltip(new Tooltip("Red / Green / Blue // Opacity")); colorBox.getChildren().add(rgbLabel); return colorBox; } /** * Extracts a double between 0.0 and 1.0 inclusive from the provided String. * * @param colorString String from which a double is extracted. * @return Double between 0.0 and 1.0 inclusive based on provided String; * will be 0.0 if provided String cannot be parsed. */ private double extractValidColor(final String colorString) { double colorValue = 0.0; try { colorValue = Double.valueOf(colorString); } catch (Exception exception) { colorValue = 0.0; err.println("Treating '" + colorString + "' as " + colorValue); } finally { if (colorValue < 0) { colorValue = 0.0; err.println("Treating '" + colorString + "' as " + colorValue); } else if (colorValue > 1) { colorValue = 1.0; err.println("Treating '" + colorString + "' as " + colorValue); } } return colorValue; } /** * Build pane with ability to specify own RGB values and see color. * * @return Pane with ability to specify colors. */ private Pane buildCustomColorPane() { final HBox customBox = new HBox(); final Button button = new Button("Display Color"); button.setPrefWidth(COLOR_NAME_WIDTH); button.setOnMouseClicked(new EventHandler() { @Override public void handle(MouseEvent t) { final Color customColor = new Color(extractValidColor(redField.getText()), extractValidColor(greenField.getText()), extractValidColor(blueField.getText()), 1.0); customColorRectangle.setFill(customColor); } }); customBox.getChildren().add(button); customBox.getChildren().add(this.customColorRectangle); customBox.getChildren().add(this.redField); customBox.getChildren().add(this.greenField); customBox.getChildren().add(this.blueField); return customBox; } /** * Build the main pane indicating JavaFX 2's pre-defined Color instances. * * @return Pane containing JavaFX 2's pre-defined Color instances. */ private Pane buildColorsPane() { final VBox colorsPane = new VBox(); final Field[] fields = Color.class.getFields(); // only want public for (final Field field : fields) { if (field.getType() == Color.class) { try { final Color color = (Color) field.get(null); final String colorName = field.getName(); colorsPane.getChildren().add(buildColorBox(color, colorName)); } catch (IllegalAccessException illegalAccessEx) { err.println( "Securty Manager does not allow access of field '" + field.getName() + "'."); } } } colorsPane.getChildren().add(buildCustomColorPane()); return colorsPane; } /** * Start method overridden from parent Application class. * * @param stage Primary stage. * @throws Exception JavaFX application exception. */ @Override public void start(final Stage stage) throws Exception { final Group rootGroup = new Group(); final Scene scene = new Scene(rootGroup, 700, 725, Color.WHITE); final ScrollPane scrollPane = new ScrollPane(); scrollPane.setPrefWidth(scene.getWidth()); scrollPane.setPrefHeight(scene.getHeight()); scrollPane.setContent(buildColorsPane()); rootGroup.getChildren().add(scrollPane); stage.setScene(scene); stage.setTitle("JavaFX Standard Colors Demonstration"); stage.show(); } /** * Main function for running JavaFX application. * * @param arguments Command-line arguments; none expected. */ public static void main(final String[] arguments) { Application.launch(arguments); } } The snapshots shown next demonstrate this simple application. The first snapshot shows the application after loading. The second snapshot shows the application after scrolling down to the bottom and demonstrates use of the Tooltip and of the TextField.setPrompt(String) method. The third image shows the results of providing red/green/blue values and clicking on the button to see the corresponding color. The simple JavaFX 2 application shown in this post makes it easy to get an idea of what colors are available as standard JavaFX 2 public static Color fields. It also allows one to enter red/green/blue values that might be provided to the Color constructor to obtain an instance of Color. From http://marxsoftware.blogspot.com/2012/02/viewing-javafx-2-standard-colors.html

Java Collections allows you to add one or more elements with the same key by using the MultiValueMap class, found in the Apache org.apache.commons.collections package (http://commons.apache.org/collections/): package multihashmap.example; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Set; import org.apache.commons.collections.map.MultiValueMap; public class MultiHashMapExample { public static void main(String[] args) { List list; MultiValueMap map = new MultiValueMap(); map.put("A", 4); map.put("A", 6); map.put("B", 7); map.put("C", 1); map.put("B", 9); map.put("A", 5); Set entrySet = map.entrySet(); Iterator it = entrySet.iterator(); System.out.println(" Object key Object value"); while (it.hasNext()) { Map.Entry mapEntry = (Map.Entry) it.next(); list = (List) map.get(mapEntry.getKey()); for (int j = 0; j < list.size(); j++) { System.out.println("\t" + mapEntry.getKey() + "\t " + list.get(j)); } } } } Since Java Core does’t come with some solutions for supporting multiple keys, using the org.apache.commons.collections seems to be a proper way to deal with multiple keys. And the output is: From http://e-blog-java.blogspot.com/2012/02/how-to-allow-duplicate-key-in-java.html

today i have prepared another really great tutorial for you. recently i started development of my own radio software (as a module for dolphin cms) and got some interesting results i would like to share with you. it will be nice looking (css3) radio script that consists of three main elements: the header (with animated search bar and integrated radio player), the left side (with a list of categories and subcategories) and the right side (which will contain a list of recent or filtered stations). here's the final result of our player: here's our live demo and downloadable package: ok, download our source files and lets start coding! step 1. html markup this is the markup of one of the template files. this is a template of our main (index) page: templates/main_page.html stream radio script back to original tutorial on script tutorials alternative classic alternativeindustrialnew wavepunk classical modernoperapianoromanticsymphony electronic breakbeatdanceelectrohousetechnotrance metal classic metalheavy metalmetalcorepower metal pop dance popoldiestop 40world pop __stations__ powered by script tutorials first, pay attention to how the script loads the jquery library from google. this can be pretty useful if you don’t like to keep this file directly on your host. our header element contains a nice search bar with an embedded jasl player ( i used a great ffmp3 live stream player ), which allows us to play audio streams without any problems. next, on the left-hand side (beneath the header) we have a ul-li based list of categories and subcategories. the right-hand side will contain a list of the most recent stations and, when we search or select a category, the right-hand side will be filtered by ajaxy. for now – it contains __stations__ key (template key) and we will replace the actual value with php. on to our next template file, the radio player: templates/radio.html of course, it contains its own template keys (__title__ and __stream__) which we will use after. step 2. css here are our stylesheets files: css/main.css the first one contains the styles of our test page (this file is always available in our package) css/radio.css /* header area */ .header { height:62px; } .header input { background:#aaa url(../images/search.png) no-repeat 5px center; border:1px solid #888; border-radius:10px; float:right; margin:14px 10px 0 0; outline:none; padding-left:20px; width:200px; -webkit-transition: 0.5s; -moz-transition: 0.5s; -o-transition: 0.5s; transition: 0.5s; } .header input:focus { background-color:#eee; width:300px; } .header > span { display:block; float:left; line-height:40px; padding:7px; -webkit-transition: 0.5s; -moz-transition: 0.5s; -o-transition: 0.5s; transition: 0.5s; } /* stations list */ .stlist { float:right; margin-right:1%; width:71%; } .stlist ul { list-style:none outside none; margin:0; padding:0; } .stlist ul li { border-bottom:1px dotted #444; overflow:hidden; padding:10px; } .stlist ul li > a > img { border:1px solid #ccc; float:left; height:85px; margin-right:15px; padding:1px; width:85px; } .stlist ul li > div { float:right; margin-left:15px; margin-top:-5px; } .stlist ul li > p.label,.stlist ul li > p.track { font-size:11px; font-weight:700; } .stlist ul li > p.label { color:#888; } .stlist ul li > p.channel { font-size:14px; font-weight:700; margin-bottom:17px; } /* genres list */ .genres_par { border-right:1px solid #ccc; float:left; width:26%; } ul.genres,ul.genres ul { list-style-type:none; margin:0; padding:0; } ul.genres ul { display:none; overflow:hidden; padding:0 15px; } ul.genres ul li { margin:3px; } ul.genres a { color:#333; display:block; font-size:18px; padding:4px 0; text-align:center; text-decoration:none; } ul.genres ul a { font-size:12px; text-align:left; } ul.genres li { border-bottom:1px solid #ccc; margin:0; } ul.genres li ul li a { background:none repeat scroll 0 0 #5bb951; border-radius:2px; color:#fff; font-size:12px; padding:6px; } ul.genres li ul li a:hover { background-color:#53854e; } step 3. js js/script.js $(document).ready(function(){ $('#search').blur(function() { if ('' == $('#search').val()) $('#search').val('search'); }); $('#search').focus(function() { if ('search' == $('#search').val()) $('#search').val(''); }); $('ul.genres li a').click( // category slider function() { var checkelement = $(this).next(); if((checkelement.is('ul')) && (!checkelement.is(':visible'))) { $('.genres li ul').slideup(150); $(this).next().slidetoggle(150); } } ); $('ul.genres ul li a').click( // get stations by category function() { $.ajax({ type: 'get', url: 'index.php', data: 'action=get_genre_stations&id=' + $(this).parent().attr('id') + '&name=' + $(this).parent().attr('val'), success: function(data){ $('.stlist').fadeout(400, function () { $('.stlist').html(data); $('.stlist').fadein(400); }); } }); } ); }); function play(id) { // play function $('#rplayer').load('index.php?action=play&id=' + id, function() {}); return false; } function get_stations_by_keyword() { // get stations by keyword var keyword = $('#search').val().replace(/ /g,"+"); $.ajax({ type: 'get', url: 'index.php', data: 'action=get_keyword_stations&key=' + keyword, success: function(data){ $('.stlist').fadeout(400, function () { $('.stlist').html(data); $('.stlist').fadein(400); }); } }); } as you see – there's nothing difficult there. just several event handlers, and two new functions (to play radio station and to search for stations by keyword). step 4. php index.php =') == 1) error_reporting(e_all & ~e_notice & ~e_deprecated); else error_reporting(e_all & ~e_notice); $astations = array( 0 => array( 'category' => 31, 'name' => 'eurodance', 'desc' => 'the newest and best of eurodance hits', 'url' => 'http://www.di.fm/eurodance', 'br' => 96, 'stream' => 'http://scfire-mtc-aa06.stream.aol.com:80/stream/1024' ), 1 => array ( 'category' => 34, 'name' => 'house', 'desc' => 'silky sexy deep house music direct from new york city!', 'url' => 'http://www.di.fm/house', 'br' => 96, 'stream' => 'http://scfire-ntc-aa04.stream.aol.com:80/stream/1007' ), 2 => array ( 'category' => 13, 'name' => 'trance', 'desc' => 'the hottest, freshest trance music from around the globe!', 'url' => 'http://www.di.fm/trance', 'br' => 96, 'stream' => 'http://scfire-ntc-aa04.stream.aol.com:80/stream/1003' ), 3 => array ( 'category' => 51, 'name' => 'electro house', 'desc' => 'an eclectic mix of electro and dirty house', 'url' => 'http://www.di.fm/electro', 'br' => 96, 'stream' => 'http://scfire-ntc-aa04.stream.aol.com:80/stream/1025' ) ); function searchbycat($icat, $astations) { $ares = array(); foreach ($astations as $i => $ainfo) { if ($ainfo['category'] == $icat) { $ares[$i] = $ainfo; } } return $ares; } function searchbykeyword($skey, $astations) { $ares = array(); foreach ($astations as $i => $ainfo) { if (false !== strpos($ainfo['name'], $skey) || false !== strpos($ainfo['desc'], $skey)) { $ares[$i] = $ainfo; } } return $ares; } function parsestationlist($adata) { $sstations = ''; if (is_array($adata) && count($adata) > 0) { foreach ($adata as $i => $a) { $sstationid = $i; $sstationbr = (int)$a['br']; $sstationname = $a['name']; $sstationdesc = $a['desc']; $sstationurl = $a['url']; $sthumb = 'media/'.($sstationid+1).'.png'; $sstations .= << bitrate: {$sstationbr} {$sstationname} {$sstationdesc} {$sstationurl} eof; } } $sstations = ($sstations == '') ? 'nothing found' : $sstations; return '' . $sstations . ''; } switch ($_get['action']) { case 'play': $i = (int)$_get['id']; $ainfo = $astations[$i]; $avars = array ( '__stream__' => $ainfo['stream'], '__title__' => $ainfo['name'] ); echo strtr(file_get_contents('templates/radio.html'), $avars); exit; break; case 'get_genre_stations': $i = (int)$_get['id']; $asearch = searchbycat($i, $astations); $sstations = parsestationlist($asearch); header('content-type: text/html; charset=utf-8'); echo $sstations; exit; break; case 'get_keyword_stations': $skey = $_get['key']; $asearch = searchbykeyword($skey, $astations); $sstations = parsestationlist($asearch); header('content-type: text/html; charset=utf-8'); echo $sstations; exit; break; } $slaststations = parsestationlist($astations); echo strtr(file_get_contents('templates/main_page.html'), array('__stations__' => $slaststations)); at the beginning, i have prepared a list of our radio stations (4 stations total). then, two search functions: ‘searchbycat’ and ‘searchbykeyword’. next, the special function ‘parsestationlist’ which will transform array with filtered stations into its html representation. finally, a little switch case to manage with our inner ajax commands. conclusion you are always welcome to enhance our script and share your ideas. i will be glad to see your thanks and comments. good luck!

for a while now, we had been operating in the wild west when it comes to building our applications and deploying to production. builds were typically done straight from the developer’s ide and manually deployed to one of our app servers. we had a manual process in place, where the developer would do the following steps. check all project code into subversion and tag build the application. archive the application binary to a network drive deploy to production update our deployment wiki with the date and version number of the app that was just deployed. the problem is that there were occasionally times where one of these steps were missed, and it always seemed to be at a time when we needed to either rollback to the previous version, or branch from the tag to do a bugfix. sometimes the previous version had not been archived to the network, or the developer forgot to tag svn. we were already using jenkins to perform automated builds, so we wanted to look at extending it further to perform release builds. the maven release plug-in provides a good starting point for creating an automated release process. we have also just started using the nexus maven repository and wanted to incorporate that as well to archive our binaries to, rather than archiving them to a network drive. the first step is to set up the project’s pom file with the deploy plugin as well as include configuration information about our nexus and subversion repositories. org.apache.maven.plugins maven-release-plugin 2.2.2 http://mks:8080/svn/jrepo/tags/frameworks/siestaframework the release plugin configuration is pretty straightforward. the configuration takes the subversion url of the location where the tags will reside for this project. the next step is to configure the svn location where the code will be checked out from. scm:svn:http://mks:8080/svn/jrepo/trunk/frameworks/siestaframework http://mks:8080/svn the last step in configuring the project is to set up the location where the binaries will be archived to. in our case, the nexus repository. lynden-java-release lynden release repository http://cisunwk:8081/nexus/content/repositories/lynden-java-release the project is now ready to use the maven release plug-in. the release plugin provides a number of useful goals. release:clean – cleans the workspace in the event the last release process was not successful. release: prepare – performs a number of operations checks to make sure that there are no uncommitted changes. ensures that there are no snapshot dependencies in the pom file, changes the version of the application and removes snapshot from the version. ie 1.0.3-snapshot becomes 1.0.3 run project tests against modified poms commit the modified pom tag the code in subersion increment the version number and append snapshot. ie 1.0.3 becomes 1.0.4-snapshot commit modified pom release: perform – performs the release process checks out the code using the previously defined tag runs the deploy maven goal to move the resulting binary to the repository. putting it all together the last step in this process is to configure jenkins to allow release builds on-demand, meaning we want the user to have to explicitly kick off a release build for this process to take place. we have download and installed the release jenkins plug-in in order to allow developers to kick off release builds from jenkins. the release plug-in will execute tasks after the normal build has finished. below is a screenshot of the configuration of one of our projects. the release build option for the project is enabled by selecting the “configure release build” option in the “build environment” section. the maven release plug-in is activated by adding the goals to the “after successful release build” section. (the –b option enables batch mode so that the release plug-in will not ask the user for input, but use defaults instead.) once the release option has been configured for a project there will be a “release” icon on the left navigation menu for the project. selecting this will kick off a build and then the maven release process, assuming the build succeeds. finally a look at svn and nexus verifies that the build for version 1.0.4 of the siesta-framework project has been tagged in svn and uploaded to nexus. the next steps for this project will be to generate release notes for release builds, and also to automate a deployment pipeline, so that developers can deploy to our test, staging and production servers via jenkins rather than manually from their development workstations. twitter: @robterp blog: http://rterp.wordpress.com

v8js is a new PHP extension able to run JavaScript code inside V8, Google's JavaScript interpreter that powers for example Chrome and NodeJS. This extension is highly alpha - and its API would probably change in the months ahead. Since documentation is lacking, I invite you to repeat the discovering process I follow in this post in case you find some differences in a new version of v8js. Installation V8 must be present on the machine in order to install the extension. On a Debian/Ubuntu system, run the following: sudo apt-get install libv8-dev libv8-dbg libv8-dev will also install libv8 in its latest version. Afterwards, download and compile the extension with: sudo pecl install v8js There are no more requirements for compilation apart from the usual dependencies for PECL packages, like build-essential. After that, add: extension=v8js.so to php.ini or to a section in conf.d. $ php -m | grep v8 v8js will confirm you the extension is loaded. Some introspection PHP's reflection let us take a look at the classes and methods provided by this extension, even without documentation available. It probably hasn't been written yet, due to the unstable API. $ php -r 'var_dump(get_declared_classes());' | grep V8 string(8) "V8Object" string(10) "V8Function" string(4) "V8Js" string(13) "V8JsException" $ php -r '$class = new ReflectionClass("V8Js"); var_dump($class->getMethods());' array(5) { [0]=> &object(ReflectionMethod)#2 (2) { ["name"]=> string(11) "__construct" ["class"]=> string(4) "V8Js" } [1]=> &object(ReflectionMethod)#3 (2) { ["name"]=> string(13) "executeString" ["class"]=> string(4) "V8Js" } [2]=> &object(ReflectionMethod)#4 (2) { ["name"]=> string(19) "getPendingException" ["class"]=> string(4) "V8Js" } [3]=> &object(ReflectionMethod)#5 (2) { ["name"]=> string(17) "registerExtension" ["class"]=> string(4) "V8Js" } [4]=> &object(ReflectionMethod)#6 (2) { ["name"]=> string(13) "getExtensions" ["class"]=> string(4) "V8Js" } } $ php -r '$v8 = new V8Js(); var_dump($v8->executeString("1+2+3"));' int(6) Interesting! We have just executed our first JavaScript expression inside a PHP process. Apparently the last statement's value is returned by the executeString() method, with a rough conversion preserving the type: $ php -r '$v8 = new V8Js(); var_dump($v8->executeString("var obj = {}; obj.field = 1; obj.field++; obj.field;"));' int(2) Syntax or runtime errors are signaled with a V8JsException: $ php -r '$v8 = new V8Js(); var_dump($v8->executeString("var obj = {"));' PHP Fatal error: Uncaught exception 'V8JsException' with message 'V8Js::executeString():1: SyntaxError: Unexpected end of input' in Command line code:1 Stack trace: #0 Command line code(1): V8Js->executeString('var obj = {') #1 {main} thrown in Command line code on line 1 Let's add more difficulty The FizzBuzz kata OO solution is an example of JavaScript code creating an object and executing anonymous functions: it's a good test bench for our integration.Since evaluating a variable as the last line returns it, that is our channel of communication, supporting integers, strings, floats, booleans, arrays (not objects at this time). Meanwhile, input for JavaScript code can be embedded into the executed string. This code will output string(8) "FizzBuzz": executeString($javaScriptCode)); By changing it a bit, we can build a JSON string by backslashing the double quotes ("), and returns it in lieu of an object to communicate to the PHP process a complex result: ... var myFizzBuzz = new FizzBuzz({3 : "Fizz", 5 : "Buzz"}); "{\"15\" : \"" + myFizzBuzz.accept(15) + "\", \"5\" : \"" + myFizzBuzz.accept(5) + "\"}"; '; $v8 = new V8Js(); $result = $v8->executeString($javaScriptCode); var_dump($result); var_dump(json_decode($result)); The output is: string(33) "{"15" : "FizzBuzz", "5" : "Buzz"}" object(stdClass)#2 (2) { ["15"]=> string(8) "FizzBuzz" ["5"]=> string(4) "Buzz" } Wiring Executing an external script would be nice: it would provide better stack traces, with traceable line numbers at the JavaScript level. It would also mean we won't need backslashing for single quotes, simplifying the syntax. We cannot load scripts on the JavaScript side out of the box, due to V8 missing this functionality (Node JS adds this feature) but we can load the code on the PHP Side: // test.js $ php loadingfiles.php string(24) "test.js file was loaded." // loadingfiles.php executeString($javascriptCode); var_dump($result); Execution results in: $ php loadingfiles.php string(24) "test.js file was loaded." However, we still miss the capability of including JavaScript libraries. Conclusion There are many possible use cases for v8js, like sandboxed scripting or the integration of some code which was written for the client side. That would not be the most clean solution, but it's a Turing complete approach, so why not? After all, it's already possible to run PHP on Java or Python and Ruby on .NET. JavaScript is becoming ubiquitous, so why not providing support for it, even in a caged box?

In my previous article on the server lifecycle I mentioned ConfigurationDrift, a term that I’ve either coined, or I’ve forgotten where I originally heard, although most likely I got it from the Puppet Labs folks. Configuration Drift is the phenomenon where running servers in an infrastructure become more and more different as time goes on, due to manual ad-hoc changes and updates, and general entropy. A nice automated server provisioning process as I’ve advocated helps ensure machines are consistent when they are created, but during a given machine’s lifetime it will drift from the baseline, and from the other machines. There are two main methods to combat configuration drift. One is to use automated configuration tools such as Puppet or Chef, and run them frequently and repeatedly to keep machines in line. The other is to rebuild machine instances frequently, so that they don’t have much time to drift from the baseline. The challenge with automated configuration tools is that they only manage a subset of a machine’s state. Writing and maintaining manifests/recipes/scripts is time consuming, so most teams tend to focus their efforts on automating the most important areas of the system, leaving fairly large gaps. There are diminishing returns for trying to close these gaps, where you end up spending inordinate amounts of effort to nail down parts of the system that don’t change very often, and don’t matter very much day to day. On the other hand, if you rebuild machines frequently enough, you don’t need to worry about running configuration updates after provisioning happens. However, this may increase the burden of fairly trivial changes, such as tweaking a web server configuration. In practice, most infrastructures are probably best off using a combination of these methods. Use automated configuration, continuously updated, for the areas of machine configuration where it gives the most benefit, and also ensure that machines are rebuilt frequently. The frequency of rebuilds will vary depending on the nature of the services provided and the infrastructure implementation, and may even vary for different types of machines. For example, machines that provide network services such as DNS may be rebuilt weekly, while those which handle batch processing tasks may be rebuilt on demand. Source: http://kief.com/configuration-drift.html

(get wcf.js on github!) Take a look at the following code: var binding = new WSHttpBinding( { MessageEncoding: "Mtom" , SecurityMode:"TransportWithMessageCredential" }) , proxy = new Proxy(binding) proxy.ClientCredentials.Username.Username = "yaron"; proxy.ClientCredentials.Username.Password = "1234"; proxy.send(message, function(response) { console.log(response) }); Do you see anything...um, special? Well c# already has the "var" keyword since version 3.0 so maybe it is some kind of a c#-ish dialect? Or maybe it is a CTP for javascript as a CLR language? Or something related to the azure sdk for node.js? Not at all. This is a snippet from wcf.js - a pure javascript node.js module that makes wcf and node.js work together! As node assumes its central place in modern web development, many developers build node apps that must consume downstream wcf services. Now if these services use WCF Web API ASP.NET Web API it is very easy. It is also a breeze if you are in a position to add a basic http binding to the Wcf service, and just a little bit of more work if you plan to employ a wcf router to do the protocol bridging. Wcf.js is a library that aims to provide a pure-javascript development experiece for such scenarios. Note that building new node.js ws-* based services is a non-goal for this project. Putting aside all the religious wars, Soap is not the "node way", so you should stick to Rest where you'll get good language support (json) and built-in libraries. "Hello, Wcf... from node" You are closer than you think to consume your first Wcf service node.js: 1. Create a new wcf web site in VS and call it "Wcf2Node". If you use .Net 4 than BasicHttpBinding is the default, otherwise in web.config replace WsHttp with BasicHttp. No need to deploy, just run the service in VS using F5. 2. Create anywhere a folder for the node side and from the command line enter its root and execute: $> npm install wcf.js 3. In the same folder create test.js: var BasicHttpBinding = require('wcf.js').BasicHttpBinding , Proxy = require('wcf.js').Proxy , binding = new BasicHttpBinding() , proxy = new Proxy(binding, " http://localhost:12/Wcf2Node/Service.svc") , message = '' + '' + '' + '' + '123' + '' + '' + '' proxy.send(message, "http://tempuri.org/IService/GetData", function(response, ctx) { console.log(response) }); 4. In test.js, change the port 12 (don't ask...) to the port your service runs on. 5. Now we can execute node: $> node test.js 6. You should now see the output soap on the console. Of course this sample is not very interesting and you may be better off sending the raw soap using request. Let's see something more interesting. If your service uses ssl + username token (transport with message credential), the config may look like this: The following modifications to the previous example will allow to consume it from node: ... binding = new WSHttpBinding( { SecurityMode: "TransportWithMessageCredential" , MessageClientCredentialType: "UserName" }) ... proxy.ClientCredentials.Username.Username = "yaron"; proxy.ClientCredentials.Username.Password = "1234"; proxy.send(...) And here is the wire soap: 2012-02-26T11:03:40Z 2012-02-26T11:08:40Z yaron 1234 123 If you use Mtom check out this code: (The formatting here is a bit strage due to my blog layout - it looks much better in github!) var CustomBinding = require('wcf.js').CustomBinding , MtomMessageEncodingBindingElement = require('wcf.js').MtomMessageEncodingBindingElement , HttpTransportBindingElement = require('wcf.js').HttpTransportBindingElement , Proxy = require('wcf.js').Proxy , fs = require('fs') , binding = new CustomBinding( [ new MtomMessageEncodingBindingElement({MessageVersion: "Soap12WSAddressing10"}), , new HttpTransportBindingElement() ]) , proxy = new Proxy(binding, "http://localhost:7171/Service/mtom") , message = '' + '' + '' + '' + '' + '' + '' + '' + '' + '' proxy.addAttachment("//*[local-name(.)='File1']", "me.jpg"); proxy.send(message, "http://tempuri.org/IService/EchoFiles", function(response, ctx) { var file = proxy.getAttachment("//*[local-name(.)='File1']") fs.writeFileSync("result.jpg", file) }); Mtom is a little bit trickier since wcf.js needs to know which nodes are binary. Using simple xpath can help you achieve that. Getting your hands dirty with Soap Wcf.js uses soap in its raw format. Code generation of proxies does not resonate well with a dynamic language like javascript. I also assume you are consuming an existing service which already has working clients so you should be able to get a working soap sample. And if you do like some level of abstraction between you and your soap I recommend node-soap, though it still does not integrate with wcf.js. If you will use raw soap requests and responses you would need a good xml library. And while node has plenty of dom / xpath libraries, they are not windows friendly. My next post will be on a good match here. Supported standards Wcf implements many of the ws-* standards and even more via proprietary extensions. The first version of wcf.js supports the following: MTOM WS-Security (Username token only) WS-Addressing (all versions) HTTP(S) The supported binding are: BasicHttpBinding WSHttpBinding CustomBinding What do you want to see next? Let me know. Get the code Wcf.js is hosted in GitHub, and everyone is welcome to contribute features and fixes if needed. Wcf.js is powered by ws.js, the actual standards implementation, which I will introduce in an upcoming post.

kendo ui is html 5 and jquery based framework and it helps you to create modern web applications. kendo ui helps you in data binding in animations with ui widgets like grid and chart with drag and drop api in touch support. download kendo ui from here once you download you get these folders: navigate to the 'example' folder for examples of various widgets. if you want to start developing web applications using kendoui then you need to add the required file in your project. you need to add the below files in the script folder: and you need to add the below files in the style folder: even though i have added script files and css files in the script folder and style folders respectively, you are free to keep them anywhere you want. after adding these files you need to link them in the header of the html page. you can add the reference as below: in a later post i will go into the details of kendo ui and play around with all other aspects. however, working with any widgets is very intuitive. for example, if you want to work with kendo autocomplete , you can do that as below: and using jquery you can assign the value as below: putting all html and script code together: test.htm kendo ui demo when you run test.htm in your browser, you should get this output: in later posts i will get into detail about all widgets. i hope this post is useful. thanks for reading. source: http://debugmode.net/2012/02/18/introduction-to-telerik-kedno-ui/

This is an experiment for a real-time tracking of a football match using only web technologies. In this case I’ve chosen to track a football match from Futbol Club Barcelona (fcb). All the work is made by the browser and it’s interactive (there are four checkboxes to activate/deactivate each tracker). It is based on tracking the location of colored objects in the frames using the HSV colour space. As a practical use for the tracker, I’ve added a smart volume feature that activates the sound only when there are goal chances (every time the ball is near the area). So you can browse other pages and change to the video one only when chances are happening. It works based on the quantity of green color in the sides of the video. The path tracker shows ‘possible’ passes between fcb players If you want to watch it in action here is the demo So far it only works in chrome and firefox and because of the low resolution of the video (and my limited skills), the tracking is not perfect, but it could be improved for tracking videos from external sources like Youtube, Veetle, etc. Here is the code: function rgbToHsv(r, g, b){ r = r/255, g = g/255, b = b/255; var max = Math.max(r, g, b), min = Math.min(r, g, b); var h, s, v = max; var d = max - min; s = max == 0 ? 0 : d / max; if(max == min){ h = 0; // achromatic }else{ switch(max){ case r: h = (g - b) / d + (g < b ? 6 : 0); break; case g: h = (b - r) / d + 2; break; case b: h = (r - g) / d + 4; break; } h /= 6; } return [h, s, v]; } //Main object var processor = { isFirefox35: function() { // Let a chance to the navigator to deal with it: return true; var ua = navigator.userAgent; // Gecko ? if (ua.indexOf("Gecko") == -1) return false; // Geck >= 1.9.1 ? return !(ua.indexOf("rv:1.9.1") == -1 && ua.indexOf("rv:1.9.2") == -1); }, // Init doLoad: function() { if (!this.isFirefox35()) { document.getElementById("nofirefoxbeta").style.display = "block"; } // Some init this.displayBackground = true; this.video = document.getElementById("video"); this.mirrorVideo = document.getElementById("mirrorVideo"); this.mirrorVideoCtx = this.mirrorVideo.getContext("2d"); var self = this; // If the videos end, play again this.video.addEventListener("ended", function(){ try { clearTimeout(self.timeout); } catch(e){} self.video.play(); // Work around: https://bugzilla.mozilla.org/show_bug.cgi?id=488287 self.videoIsPlaying(); }, true); // Set the events listeners for the main video (update button) this.video.addEventListener("pause", function() { self.updateButtons(false); }, false); this.pageLoaded = true; this.startPlayer(); }, videoIsPlaying: function() { this.updateButtons(true); this.timerCallback(); }, videoIsReady: function() { this.videoLoaded = true; this.startPlayer(); }, startPlayer: function() { if (!this.videoLoaded || !this.pageLoaded) return; document.getElementById("wait").style.display = "none"; document.getElementById("player").style.display = "block"; this.width = this.video.videoWidth; this.height = this.video.videoHeight; this.mirrorVideo.width = this.width; this.mirrorVideo.height = this.height; }, playVideo:function(){ this.video.play(); this.videoIsPlaying(); }, stopVideo: function(){ this.video.pause(); clearTimeout(this.timeout); }, volumeDown:function(){ if(this.video.volume>0) this.video.volume=Math.round((this.video.volume - 0.1)*10)/10; }, volumeUp:function(){ if(this.video.volume<1) this.video.volume=Math.round((this.video.volume + 0.1)*10)/10; }, // Main loop timerCallback: function() { if (this.video.paused || this.video.ended) { return; } this.computeFrame(); var self = this; this.timeout = setTimeout(function () { self.timerCallback(); }, 50); }, // Update the SVG button updateButtons: function(play) { document.getElementById("playButton").setAttribute("play", play); document.getElementById("stopButton").setAttribute("play", play); }, // Handling some patterns (text, drawing) has_green_around: function(frameData, pos) { pos_left = pos+ 24; pos_right = pos - 24; r_left = frameData[pos_left+0]; g_left = frameData[pos_left+1]; b_left = frameData[pos_left+2]; r_right = frameData[pos_right+0]; g_right = frameData[pos_right+1]; b_right = frameData[pos_right+2]; return ((r_left < 125 && g_left > 125 && b_left < 80) && (r_right < 125 && g_right > 125 && b_right < 80)); }, is_team_color: function(frameData, pos){ for (i=pos-4; i<=pos+4; i+=4){ r = frameData[i+0]; g = frameData[i+1]; b = frameData[i+2]; hsv = rgbToHsv(r,g,b); //if(hsv[0] < 0.60|| hsv[1] < 0.35) if((hsv[0] < 0.40 || hsv[1] < 0.25 || hsv[2] < 0) || (hsv[0] > 0.70 || hsv[1] > 1 || hsv[2] > 1)) return false; } return true; }, is_ball_color: function(frameData, pos){ for (i=pos-4; i<=pos+4; i+=4){ r = frameData[i+0]; g = frameData[i+1]; b = frameData[i+2]; hsv = rgbToHsv(r,g,b); if((hsv[0] < 0.23 || hsv[1] < 0.40 || hsv[2] < 0.90) || (hsv[0] > 0.27 || hsv[1] > 0.50 || hsv[2] > 1)) return false; } return true; }, dist: function(x1, y1, x2, y2) { return Math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2)); }, computeFrame: function() { try { this.mirrorVideoCtx.clearRect(0, 0, this.width, this.height); this.mirrorVideoCtx.drawImage(this.video, 0, 0, this.width, this.height); } catch(e) { return; } var frame = this.mirrorVideoCtx.getImageData(0, 0, 640, 360); this.mirrorVideoCtx.fillStyle = 'rgba(200,200,200,0.5)'; this.mirrorVideoCtx.strokeStyle = 'rgba(200,200,200,0.5)'; this.mirrorVideoCtx.lineWidth = 1; var x, y; var weight = 0; var team_shape = null; var ball_shape = null; var ball_found = false; var ball_tracker = document.getElementById("balltracker").checked; var team_tracker = document.getElementById("teamtracker").checked; var path_tracker = document.getElementById("pathtracker").checked; var smart_volume = document.getElementById("smartvolume").checked; var shapes = []; var x, y; var green_bar_left = 0; var green_bar_rigth =0; var green_bar_down = 0; var frame_length = frame.data.length/4; // We dont' need to compute each pixels var step = 4; for (var i = 0; i < frame_length; i += step) { pos = i*4; x = i % this.width; y = Math.round(i / this.width); if (x == 4) green_bar_left += g; else if (x == this.width-4) { green_bar_rigth += g; if (y == 4) green_bar_down += g; } ball_found = ball_tracker && this.is_ball_color(frame.data, pos); team_found = team_tracker && this.is_team_color(frame.data, pos); if (this.has_green_around(frame.data, pos) && (ball_found || team_found)){ if (ball_found) { ball_shape = {}; ball_shape.x = x; ball_shape.y = y; } if(team_found) { if (!team_shape) { // no shape yet, create the first one team_shape = {}; team_shape.x = x; team_shape.y = y; team_shape.weight = 1; shapes.push(team_shape); } else { var d = this.dist(x, y, team_shape.x, team_shape.y); if (d>25){ team_shape = {}; team_shape.x = x; team_shape.y = y; team_shape.weight = 1; shapes.push(team_shape); } } } } } if (shapes.length>0) { if (path_tracker){ this.mirrorVideoCtx.beginPath(); this.mirrorVideoCtx.moveTo(shapes[0].x, shapes[0].y); } for( var s=0; s0 && Math.abs(green_left_average-green_right_average)>15){ //this.volumeUp(); this.video.volume=1; document.getElementById("soundIcon").setAttribute("mute", false); }else{ this.volumeDown(); //this.video.volume=0; document.getElementById("soundIcon").setAttribute("mute", true); } } return; } } Source: http://lusob.com/2012/02/tracking-a-football-match-with-html5-and-javascript/

There is an increasing number of libraries which are described as high performance and have benchmarks to back that claim up. Here is a selection that I am aware of.

I recently spent some time learning JavaFX and doing a custom control is a good practice to dive a little bit deeper into the concepts of a new gui library. Having some background in financial software I did of course miss the equivalent of a JFormattedTextField and a JSpinner control in the current 2.0 release. So going down that road seemed like a good choice to me. And here are my controls: a NumberTextField, that can be configured with an arbitrary NumberFormat a Spinner field that also can also be configured with an arbitrary NumberFormat and controlled with the arrow keys or arrow buttons, that are part of the control The controls and an example can be downloaded as a netbeans project.The example also includes a css file that styles the spinner with either straight or rounded corners. NumberTextField The NumberTextField was pretty easy and I wouldn't even consider this a custom control as I only changed the behaviour of an already existing control. It extends a normal TextField, adds a NumberProperty that serves as the model and holds a BigDecimal (for financial applications we need exact types) and does some formatting and parsing.That's it, no big deal. package de.thomasbolz.javafx; import java.math.BigDecimal; import java.text.NumberFormat; import java.text.ParseException; import javafx.beans.property.ObjectProperty; import javafx.beans.property.SimpleObjectProperty; import javafx.beans.value.ChangeListener; import javafx.beans.value.ObservableValue; import javafx.event.ActionEvent; import javafx.event.EventHandler; import javafx.scene.control.TextField; /** * Textfield implementation that accepts formatted number and stores them in a * BigDecimal property The user input is formatted when the focus is lost or the * user hits RETURN. * * @author Thomas Bolz */ public class NumberTextField extends TextField { private final NumberFormat nf; private ObjectProperty number = new SimpleObjectProperty<>(); public final BigDecimal getNumber() { return number.get(); } public final void setNumber(BigDecimal value) { number.set(value); } public ObjectProperty numberProperty() { return number; } public NumberTextField() { this(BigDecimal.ZERO); } public NumberTextField(BigDecimal value) { this(value, NumberFormat.getInstance()); initHandlers(); } public NumberTextField(BigDecimal value, NumberFormat nf) { super(); this.nf = nf; initHandlers(); setNumber(value); } private void initHandlers() { // try to parse when focus is lost or RETURN is hit setOnAction(new EventHandler() { @Override public void handle(ActionEvent arg0) { parseAndFormatInput(); } }); focusedProperty().addListener(new ChangeListener() { @Override public void changed(ObservableValue observable, Boolean oldValue, Boolean newValue) { if (!newValue.booleanValue()) { parseAndFormatInput(); } } }); // Set text in field if BigDecimal property is changed from outside. numberProperty().addListener(new ChangeListener() { @Override public void changed(ObservableValue obserable, BigDecimal oldValue, BigDecimal newValue) { setText(nf.format(newValue)); } }); } /** * Tries to parse the user input to a number according to the provided * NumberFormat */ private void parseAndFormatInput() { try { String input = getText(); if (input == null || input.length() == 0) { return; } Number parsedNumber = nf.parse(input); BigDecimal newValue = new BigDecimal(parsedNumber.toString()); setNumber(newValue); selectAll(); } catch (ParseException ex) { // If parsing fails keep old number setText(nf.format(number.get())); } } } NumberSpinner The NumberSpinner is only slightly more complicated. It builds upon the NumberTextField and adds an increment and decrement button, that increments and decrements the value in the field by a stepwidth. Initial value, stepwidth and underlying NumberFormat are set in the constructor. The textfield and the size of the buttons are scaled according to the font size that can be - for example - set in the .css file. package de.thomasbolz.javafx; import java.math.BigDecimal; import java.text.NumberFormat; import javafx.beans.binding.NumberBinding; import javafx.beans.property.ObjectProperty; import javafx.beans.property.SimpleObjectProperty; import javafx.event.ActionEvent; import javafx.event.EventHandler; import javafx.geometry.Pos; import javafx.scene.control.Button; import javafx.scene.input.KeyCode; import javafx.scene.input.KeyEvent; import javafx.scene.layout.HBox; import javafx.scene.layout.StackPane; import javafx.scene.layout.VBox; import javafx.scene.shape.LineTo; import javafx.scene.shape.MoveTo; import javafx.scene.shape.Path; import javax.swing.JSpinner; /** * JavaFX Control that behaves like a {@link JSpinner} known in Swing. The * number in the textfield can be incremented or decremented by a configurable * stepWidth using the arrow buttons in the control or the up and down arrow * keys. * * @author Thomas Bolz */ public class NumberSpinner extends HBox { public static final String ARROW = "NumberSpinnerArrow"; public static final String NUMBER_FIELD = "NumberField"; public static final String NUMBER_SPINNER = "NumberSpinner"; public static final String SPINNER_BUTTON_UP = "SpinnerButtonUp"; public static final String SPINNER_BUTTON_DOWN = "SpinnerButtonDown"; private final String BUTTONS_BOX = "ButtonsBox"; private NumberTextField numberField; private ObjectProperty stepWitdhProperty = new SimpleObjectProperty<>(); private final double ARROW_SIZE = 4; private final Button incrementButton; private final Button decrementButton; private final NumberBinding buttonHeight; private final NumberBinding spacing; public NumberSpinner() { this(BigDecimal.ZERO, BigDecimal.ONE); } public NumberSpinner(BigDecimal value, BigDecimal stepWidth) { this(value, stepWidth, NumberFormat.getInstance()); } public NumberSpinner(BigDecimal value, BigDecimal stepWidth, NumberFormat nf) { super(); this.setId(NUMBER_SPINNER); this.stepWitdhProperty.set(stepWidth); // TextField numberField = new NumberTextField(value, nf); numberField.setId(NUMBER_FIELD); // Enable arrow keys for dec/inc numberField.addEventFilter(KeyEvent.KEY_PRESSED, new EventHandler() { @Override public void handle(KeyEvent keyEvent) { if (keyEvent.getCode() == KeyCode.DOWN) { decrement(); keyEvent.consume(); } if (keyEvent.getCode() == KeyCode.UP) { increment(); keyEvent.consume(); } } }); // Painting the up and down arrows Path arrowUp = new Path(); arrowUp.setId(ARROW); arrowUp.getElements().addAll(new MoveTo(-ARROW_SIZE, 0), new LineTo(ARROW_SIZE, 0), new LineTo(0, -ARROW_SIZE), new LineTo(-ARROW_SIZE, 0)); // mouse clicks should be forwarded to the underlying button arrowUp.setMouseTransparent(true); Path arrowDown = new Path(); arrowDown.setId(ARROW); arrowDown.getElements().addAll(new MoveTo(-ARROW_SIZE, 0), new LineTo(ARROW_SIZE, 0), new LineTo(0, ARROW_SIZE), new LineTo(-ARROW_SIZE, 0)); arrowDown.setMouseTransparent(true); // the spinner buttons scale with the textfield size // TODO: the following approach leads to the desired result, but it is // not fully understood why and obviously it is not quite elegant buttonHeight = numberField.heightProperty().subtract(3).divide(2); // give unused space in the buttons VBox to the incrementBUtton spacing = numberField.heightProperty().subtract(2).subtract(buttonHeight.multiply(2)); // inc/dec buttons VBox buttons = new VBox(); buttons.setId(BUTTONS_BOX); incrementButton = new Button(); incrementButton.setId(SPINNER_BUTTON_UP); incrementButton.prefWidthProperty().bind(numberField.heightProperty()); incrementButton.minWidthProperty().bind(numberField.heightProperty()); incrementButton.maxHeightProperty().bind(buttonHeight.add(spacing)); incrementButton.prefHeightProperty().bind(buttonHeight.add(spacing)); incrementButton.minHeightProperty().bind(buttonHeight.add(spacing)); incrementButton.setFocusTraversable(false); incrementButton.setOnAction(new EventHandler() { @Override public void handle(ActionEvent ae) { increment(); ae.consume(); } }); // Paint arrow path on button using a StackPane StackPane incPane = new StackPane(); incPane.getChildren().addAll(incrementButton, arrowUp); incPane.setAlignment(Pos.CENTER); decrementButton = new Button(); decrementButton.setId(SPINNER_BUTTON_DOWN); decrementButton.prefWidthProperty().bind(numberField.heightProperty()); decrementButton.minWidthProperty().bind(numberField.heightProperty()); decrementButton.maxHeightProperty().bind(buttonHeight); decrementButton.prefHeightProperty().bind(buttonHeight); decrementButton.minHeightProperty().bind(buttonHeight); decrementButton.setFocusTraversable(false); decrementButton.setOnAction(new EventHandler() { @Override public void handle(ActionEvent ae) { decrement(); ae.consume(); } }); StackPane decPane = new StackPane(); decPane.getChildren().addAll(decrementButton, arrowDown); decPane.setAlignment(Pos.CENTER); buttons.getChildren().addAll(incPane, decPane); this.getChildren().addAll(numberField, buttons); } /** * increment number value by stepWidth */ private void increment() { BigDecimal value = numberField.getNumber(); value = value.add(stepWitdhProperty.get()); numberField.setNumber(value); } /** * decrement number value by stepWidth */ private void decrement() { BigDecimal value = numberField.getNumber(); value = value.subtract(stepWitdhProperty.get()); numberField.setNumber(value); } public final void setNumber(BigDecimal value) { numberField.setNumber(value); } public ObjectProperty numberProperty() { return numberField.numberProperty(); } public final BigDecimal getNumber() { return numberField.getNumber(); } // debugging layout bounds public void dumpSizes() { System.out.println("numberField (layout)=" + numberField.getLayoutBounds()); System.out.println("buttonInc (layout)=" + incrementButton.getLayoutBounds()); System.out.println("buttonDec (layout)=" + decrementButton.getLayoutBounds()); System.out.println("binding=" + buttonHeight.toString()); System.out.println("spacing=" + spacing.toString()); } } number_spinner.css Last but not least the control can be styled in the css file. I played around with two looks, rounded corners and straight corners (see attached screenshots). You can switch between them by changing the border/background-radiuses in #NumberField, #ButtonBox, #SpinnerButtonUp and #SpinnerButtonDown. .root{ -fx-font-size: 24pt; /* -fx-base: rgb(255,0,0);*/ /* -fx-background: rgb(50,50,50);*/ } #NumberField { -fx-border-width: 1; -fx-border-color: lightgray; -fx-background-insets:1; -fx-border-radius:3 0 0 3; /* -fx-border-radius:0 0 0 0;*/ } #NumberSpinnerArrow { -fx-fill: gray; -fx-stroke: gray; /* -fx-effect: innershadow( gaussian , black , 2 , 0.6 , 1 , 1 )*/ } #ButtonsBox { -fx-border-color:lightgray; -fx-border-width: 1 1 1 0; -fx-border-radius: 0 3 3 0; /* -fx-border-radius: 0 0 0 0;*/ } #SpinnerButtonUp { -fx-background-insets: 0; -fx-background-radius:0 3 0 0; /* -fx-background-radius:0;*/ } #SpinnerButtonDown { -fx-background-insets: 0; -fx-background-radius:0 0 3 0; /* -fx-background-radius:0;*/ } Conclusion Doing custom controls in JavaFX is really no big deal although the examples above are really easy ones. JavaFX being a pure Java API since 2.0 now integrates even better than before with languages like groovy where BigDecimal is a first class citizen. This makes it an almost perfect couple for financial desktops applications.

Execute the slow integration tests separately from unit tests and show as much information about them as possible in Sonar.

Prefix encoding, sometimes called front encoding, is yet another algorithm that tries to remove duplicated data in order to reduce its size. Its principles are simple, however this algorithm tends to be difficult to implement. To understand why, first let’s take a look at its nature. Have a look on the following dictionary. use used useful usefulness uselss uselessly uselessness Instead of keeping all these words in plain text or transferring all them over a network, we can compress (encode) them with prefix encoding. It’s clear that each of these words begins with the prefix “use” which is also the first word from the list. So we can easily compress them into the following array. $data = array( 0 => 'use', 1 => '0d', 2 => '0ful', 3 => '0fully', 4 => '0less', 5 => '0lessly', 6 => '0lessness', ); It’s clear that this is not the best compression and we can go even further by using not only the first word as prefix. $data = array( 0 => 'use', 1 => '0d', 2 => '0ful', 3 => '2ly', 4 => '0less', 5 => '4ly', 6 => '4ness', ); Now the compression is better and the good news is that decompression is a fairly simple process. However the tricky part is compression itself. The problem is that it is quite difficult to chose an appropriate prefix. In our first example this is simple, but most of the time in practice we will have more heterogeneous data. Indeed the process of compression can be very difficult for randomly generated data and the algorithm will be not only slow, but difficult to implement. The good thing is that this algorithm can be used in many cases once we know the data format in advance. So let’s see three examples where this algorithm can be very handy. Application Here are three examples of prefix encoding. As I stated above, the process of compression can be very difficult for random data, so it is a good practice to use it only if you know in advance the format of the input data. Date and time prefixes We humans often skip the first two digits of a year, so for instance we don’t always write 1995 or 1996, but we use the shorter – ‘95 and ‘96. Thus years can be encoded with shorter strings. input: (1991, 1992, 1993, 1994, 1995, 1996 output: (91, 92, 93, 94, 95, 96) The problem is that with small changes of the input stream we can confuse the decoder. Thus if we add years from the 21st century we lose the uniqueness of the data. input: (1998, 1992, 1999, 2011, 2012) output: (98, 92, 99, 11, 12) Now the decoder can decode the last two values as (1911, 1912) as “19” is considered to be the prefix. So we must know in advance that our prefix is absolutely equal for each of the values. If not the encoding format must be different. For instance we can also encode the prefix, with some special marker. input: (1998, 1992, 1932, 1924, 2001, 2012) output: (#19, 98, 92, 32, 24, #20, 01, 12) Once the decoder reads the # character it will know to decode the following number as prefix. This can be used in practice for date and time formats. Let’s say we have some datetime values, but we know that all of them are in the same day. 2012-01-31 15:33:45 2012-01-31 16:12:11 2012-01-31 17:32:35 2012-01-31 18:54:34 Obviously we can omit the date part of these strings and send (keep) only the time. Once again, we must be absolutely sure that all these values are in the same day. If not, we can use the encoding strategy of the previous example. Phone numbers Phone numbers are the typical case of prefix encoding. Not only the international code, but also the mobile network operators use prefixes for their phone numbers. Thus if we have to transfer phone numbers from, let’s say the UK, we can replace the leading “+44” with something shorter. If you happen to code a phone book for a mobile device you can save some space by compressing the data using prefix encoding and thus the user will have more space and will store more phone numbers on his or her mobile device. Phone number prefixes can be also used for database normalization. Thus you can store them in a separate db table and leave only the unique numbers from the phonebook. Geo Coordinates Using the same example from my previous post we can send GEO coordinates by removing a common prefix, for large levels of zoom. Indeed when you need to send lots of markers to your map application you can expect all of these markers to be fairly close to each other in large zoom level. On large zoom levels we can expect markers to have the same prefix. Now the coordinates of those points can have a common prefix, like the example bellow with the Subway stations. LatLon(40.762959,-73.985989) LatLon(40.761886,-73.983629) LatLon(40.762861,-73.981612) LatLon(40.764616,-73.98056) We can see that all of these GEO points have the same prefix (40.76x, -73.98x), so we can send the prefix only once. Prefix: (40.76,-73.98) Data: LatLon(2959,5989) LatLon(1886,3629) LatLon(2861,1612) LatLon(4616,056) These are only three examples of prefix encoding and this algorithm is very useful when transferring homogeneous data. Suffix Encoding Suffix encoding is practically the same algorithm as prefix encoding, with the small difference that we use to encode duplicating suffixes. Like the examples below, suffix encoding can be useful in replacing repeating last name suffixes. Johsnon Clark Jackson Or company names. Apple Inc. Google Inc. Yahoo! Inc. Here we can replace “ Inc.” with something else, but shorter. Related posts: Computer Algorithms: Data Compression with Relative Encoding Computer Algorithms: Data Compression with Run-length Encoding Computer Algorithms: Data Compression with Diagram Encoding and Pattern Substitution Source: http://www.stoimen.com/blog/2012/02/06/computer-algorithms-data-compression-with-prefix-encoding/

Right now, when I try to persist an object in Google App Engine, I’m facing the error “Java.lang.VerifyError: Expecting a stackmap frame at branch target“. I’m using JDK 7 and it seems like the problem lies with this JDK. After googling a bit, I found that there seems to be two solutions to fix this problem. Solution 1: Change to JDK 6 As simple as is, change your JDK to version 6 and you won’t be bugged by this exception anymore. Well, in my case, I have to use JDK 7. So, moving on to the solution 2. Solution 2: Configure JVM Go to Windows -> Preferences -> Installed JREs. Select the default JVM and click edit. Then add this parameter as VM argument “-XX:-UseSplitVerifier” as seen below. This should solve the issue. From http://veerasundar.com/blog/2012/01/java-lang-verifyerror-expecting-a-stackmap-frame-at-branch-target-jdk-7/