Java Servlet 3.0 Tutorial: WebServlet Annotations with NetBeans 7, Jetty and Maven
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Join For FreeJava Servlet 3.0 has been officially released for a while now. Today I’ll show you one of the new features: WebServlet Annotations. I’ll be using Netbeans 7 with Jetty and Maven to build and run the demo code.
Create a new Maven Web Application with NetBeans 7 called: Servlet3Demo
Once the project is created make sure to remove the index.jsp file as we will not be using that.
Add a new servlet to the project called: MyServlet
Prior to Servlet 3.0 you had to put all your servlet, filter, etc. information in the web.xml file. With annotations now you don’t have to rely on web.xml anymore. Below is the code for the MyServlet, note the use of annotations to define this servlet and to set some initial parameters.
package com.giantflyingsaucer.servlet3demo;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet(asyncSupported = false, name = "MyServlet", urlPatterns = {"/"},
initParams = {@WebInitParam(name="webInitParam1", value="Hello"), @WebInitParam(name="webInitParam2", value="World")})
public class MyServlet extends HttpServlet {
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
out.println("<html><head><title>MyServlet</title></head><body>");
out.write(getServletConfig().getInitParameter("webInitParam1") + " ");
out.write(getServletConfig().getInitParameter("webInitParam2"));
out.println("</body>");
out.println("</html>");
} finally {
out.close();
}
}
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
@Override
public String getServletInfo() {
return "Short description";
}
}
Now we need to add support to run Jetty and have it load up the WAR file compliments of Maven. Modify your POM to include Jetty and the Jetty plugin.
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.giantflyingsaucer</groupId>
<artifactId>Servlet3Demo</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<name>Servlet3Demo</name>
<properties>
<endorsed.dir>${project.build.directory}/endorsed</endorsed.dir>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>org.mortbay.jetty</groupId>
<artifactId>jetty-maven-plugin</artifactId>
<version>8.0.1.v20110908</version>
</dependency>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-web-api</artifactId>
<version>6.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.8.2</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>1.6</source>
<target>1.6</target>
<compilerArguments>
<endorseddirs>${endorsed.dir}</endorseddirs>
</compilerArguments>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>2.1.1</version>
<configuration>
<failOnMissingWebXml>false</failOnMissingWebXml>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.1</version>
<executions>
<execution>
<phase>validate</phase>
<goals>
<goal>copy</goal>
</goals>
<configuration>
<outputDirectory>${endorsed.dir}</outputDirectory>
<silent>true</silent>
<artifactItems>
<artifactItem>
<groupId>javax</groupId>
<artifactId>javaee-endorsed-api</artifactId>
<version>6.0</version>
<type>jar</type>
</artifactItem>
</artifactItems>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.mortbay.jetty</groupId>
<artifactId>jetty-maven-plugin</artifactId>
<version>8.0.1.v20110908</version>
<configuration>
<scanIntervalSeconds>10</scanIntervalSeconds>
<webAppConfig>
<contextPath>/</contextPath>
</webAppConfig>
</configuration>
</plugin>
</plugins>
</build>
</project>
Set the project properties for Maven like the following:
Run your project, NetBeans 7 will display a prompt which you can use the following settings.
Load the project in your browser: http://localhost:8080
You should see Hello World in the browser.
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