Although I am using Maven since a long time I never used the Jetty plugin until recently. To be able to test a REST client I created a servlet which showed me all incoming parameters and headers with the incoming request. To run the servlet in a container I decided to give the Maven Jetty plugin a go.
So first I create a web application by using the specific Maven archetype:
mvn archetype:generate -DgroupId=net.pascalalma -DartifactId=rest-service -Dversion=1.0.0-SNAPSHOT -DarchetypeArtifactId=maven-archetype-webapp
This results in the complete project and the following logging:
[INFO] Scanning for projects... [INFO] [INFO] ------------------------------------------------------------------------ [INFO] Building Maven Stub Project (No POM) 1 [INFO] ------------------------------------------------------------------------ [INFO] [INFO] >>> maven-archetype-plugin:2.2:generate (default-cli) @ standalone-pom >>> [INFO] [INFO] <<< maven-archetype-plugin:2.2:generate (default-cli) @ standalone-pom <<< [INFO] [INFO] --- maven-archetype-plugin:2.2:generate (default-cli) @ standalone-pom --- [INFO] Generating project in Interactive mode Downloading: http://artifactory.redstream.nl/repo/org/apache/maven/archetypes/maven-archetype-webapp/1.0/maven-archetype-webapp-1.0.jar Downloaded: http://artifactory.redstream.nl/repo/org/apache/maven/archetypes/maven-archetype-webapp/1.0/maven-archetype-webapp-1.0.jar (4 KB at 5.2 KB/sec) Downloading: http://artifactory.redstream.nl/repo/org/apache/maven/archetypes/maven-archetype-webapp/1.0/maven-archetype-webapp-1.0.pom Downloaded: http://artifactory.redstream.nl/repo/org/apache/maven/archetypes/maven-archetype-webapp/1.0/maven-archetype-webapp-1.0.pom (533 B at 1.1 KB/sec) [INFO] Using property: groupId = net.pascalalma [INFO] Using property: artifactId = rest-service [INFO] Using property: version = 1.0.0-SNAPSHOT [INFO] Using property: package = net.pascalalma Confirm properties configuration: groupId: net.pascalalma artifactId: rest-service version: 1.0.0-SNAPSHOT package: net.pascalalma Y: : Y [INFO] ---------------------------------------------------------------------------- [INFO] Using following parameters for creating project from Old (1.x) Archetype: maven-archetype-webapp:1.0 [INFO] ---------------------------------------------------------------------------- [INFO] Parameter: groupId, Value: net.pascalalma [INFO] Parameter: packageName, Value: net.pascalalma [INFO] Parameter: package, Value: net.pascalalma [INFO] Parameter: artifactId, Value: rest-service [INFO] Parameter: basedir, Value: /Users/pascal/projects [INFO] Parameter: version, Value: 1.0.0-SNAPSHOT [INFO] project created from Old (1.x) Archetype in dir: /Users/pascal/projects/rest-service [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS [INFO] ------------------------------------------------------------------------ [INFO] Total time: 13.057s [INFO] Finished at: Sun Feb 03 17:13:33 CET 2013 [INFO] Final Memory: 7M/81M [INFO] ------------------------------------------------------------------------ MacBook-Air-van-Pascal:projects pascal$
Next I added the servlet code to the project:
package net.pascalalma.servlets;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
*
* @author pascal
*/
public class TestRestServlet extends HttpServlet {
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
PrintWriter out = response.getWriter();
out.println("GET method called");
out.println("parameters:\n " + parameters(request));
out.println("headers:\n " + headers(request));
}
public void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
PrintWriter out = response.getWriter();
out.println("POST method called");
out.println("parameters: " + parameters(request));
out.println("headers: " + headers(request));
}
public void doDelete(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
PrintWriter out = response.getWriter();
out.println("Delete method called");
}
private String parameters(HttpServletRequest request) {
StringBuilder builder = new StringBuilder();
for (Enumeration e = request.getParameterNames(); e.hasMoreElements();) {
String name = (String) e.nextElement();
builder.append("|" + name + "->" + request.getParameter(name)+"\n");
}
return builder.toString();
}
private String headers(HttpServletRequest request) {
StringBuilder builder = new StringBuilder();
for (Enumeration e = request.getHeaderNames(); e.hasMoreElements();) {
String name = (String) e.nextElement();
builder.append("|" + name + "->" + request.getHeader(name)+"\n");
}
return builder.toString();
}
}
And configure the servlet in the ‘web.xml’. By the way the generated ‘web.xml’ wasn’t able to be shown in my Netbeans version (v7.2.1). I got the message:
Web application version is unsupported. Upgrade web.xml to version 2.4 or newer or use previous version of NetBeans
To fixed this I modified the web.xml so it starts with the following declaration of namespaces:
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
Next add the servlet to the modified ‘web.xml’:
<?xml version="1.0" encoding="UTF-8"?>
...
<display-name>Archetype Created Web Application</display-name>
<servlet>
<servlet-name>TestRestServlet</servlet-name>
<servlet-class>net.pascalalma.servlets.TestRestServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>TestRestServlet</servlet-name>
<url-pattern>/TestRestServlet</url-pattern>
</servlet-mapping>
...
Now everything is ready to test the servlet. As I said before I am going to use the Jetty plugin for this. To add the plugin to the project simply put the following in your ‘pom.xml’:
<plugins>
<plugin>
<groupId>org.mortbay.jetty</groupId>
<artifactId>jetty-maven-plugin</artifactId>
<configuration>
<scanIntervalSeconds>10</scanIntervalSeconds>
<contextPath>/</contextPath>
<scanIntervalSeconds>10</scanIntervalSeconds>
<stopKey>STOP</stopKey>
<stopPort>8005</stopPort>
<port>8080</port>
</configuration>
</plugin>
</plugins>
Now I can run the command ‘mvn jetty:run’ in my terminal to have the container running the servlet. The log should end with something like:
.... 2013-02-19 09:54:53.044:INFO:oejs.AbstractConnector:Started SelectChannelConnector@0.0.0.0:8080 [INFO] Started Jetty Server [INFO] Starting scanner at interval of 10 seconds.</code>
Now if you open a browser and go to the this url ‘http://localhost:8080/TestRestServlet?bla=true’ you will see the servlet in action and outputting to the browser:
GET method called
parameters:
|bla->true
headers:
|DNT->1
|Host->localhost:8080
|Accept->text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
|Accept-Charset->ISO-8859-1,utf-8;q=0.7,*;q=0.3
|Accept-Language->en-US,en;q=0.8
|User-Agent->Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_5) AppleWebKit/537.17 (KHTML, like Gecko) Chrome/24.0.1312.57 Safari/537.17
|Connection->keep-alive
|Cache-Control->max-age=0
|Accept-Encoding->gzip,deflate,sdch
One note: As you can see in the plugin configuration I have added a few extra parameters for my convenience. So will the container check every 10 seconds for changes in the servlet, so I don’t have to restart the Jetty container after each change of the servlet. To stop the container you can now enter the command ‘mvn jetty:stop -DstopPort=8005 -DstopKey=STOP’ in another terminal session. By the way, make sure you name the plugin ‘jetty-maven-plugin’ and not ‘maven-jetty-plugin’ because then you will be using an old version of the plugin which doesn’t pickup the configuration parameters (yes, very confusing and frustrating as I found out).
The Pragmatic Integrator 