Over a million developers have joined DZone.
{{announcement.body}}
{{announcement.title}}

Image Storage within a J2EE Web Context

DZone's Guide to

Image Storage within a J2EE Web Context

· Java Zone ·
Free Resource

Download Microservices for Java Developers: A hands-on introduction to frameworks and containers. Brought to you in partnership with Red Hat.

In the big coding world, Say you have Web Application images that needs to be uploaded or even copied from one directory to another within your application container.

The Engine behind this processing is:

- Servlet Context  or getServlet() method in some Frameworks.

Using a Controller Class within  MVC pattern for processing, it is vital we get the Real Path to our Application context using this:

String webappPath = getServlet().getServletContext().getRealPath("/"); 

Once the Real Path is attained we can process the image to any created directory within the Web Context.

Please Note:

To create a Sub-Folder, the full path of the Parent Folder needs to be added into the sub-folder path.

 
String path = context+"\\photos";
File folder = new File(path);
File subfolder = new File(context+"\\photos\\"+businessName);
log.info("Create Folder - "+folder.getPath());
//Make the Folder
if(!folder.isDirectory()){
if(folder.mkdir()){
log.info("Create Folder Done - "+folder.getPath());
if(subfolder.mkdir())
log.info("Create Sub - Folder Done - "+subfolder.getPath());
}
}
if(!("").equals(fileName)){
File storeFile = new File(subfolder.getPath(),fileName);
log.info("Store File Format - "+storeFile.getName()+" Path - "+storeFile.getPath());
if(!storeFile.exists()){
try {
log.info("File Stream Store File Format - "+storeFile.getName()+"- Path - "+storeFile.getPath());
FileOutputStream fos = new FileOutputStream(storeFile);
fos.write(fileUploaded.getFileData());
fos.flush();
fos.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return storeFile.getPath();
}else{
return "Photo Failed to load";
}

 The Servlet Context can be used to copy from one directory to another.

public void copyLocalImagesToServer(String srcFolder,String destination){




String webappPath = getServlet().getServletContext().getRealPath("/");
FileUtils file = new FileUtils(); File src = new File(srcFolder); File destDir = new File(webappPath+destination); try { file.copyDirectoryToDirectory(src, destDir); log.info("Copy Dir "+src.getPath()+" to Src - "+destDir.getPath()); } catch (IOException e) { // TODO Auto-generated catch block log.info("Image Copy Failure from "+src.getPath()+" to "+destDir.getPath()); e.printStackTrace(); } }

Remember various frameworks uses different Context methods.

Download Building Reactive Microservices in Java: Asynchronous and Event-Based Application Design. Brought to you in partnership with Red Hat

Topics:

Opinions expressed by DZone contributors are their own.

{{ parent.title || parent.header.title}}

{{ parent.tldr }}

{{ parent.urlSource.name }}