Unit tests with embeded tomcat artifacts

In the 7.x releases of Apache Tomcat, some maven artifacts are now published which include a nice and fluent embeded api to run a Tomcat instance.

So it's a nice opportunity to use it writing units to test servlets, rest api etc..
But until 7.0.25 it was only possible to do it with using a barcoding port which can cause some issues on ci servers where you are not sure ports are not used by something else running.

I have personally sended a RFC to ITEF to have port allocation for only my personal use on my birthday year or zip code port but strangely this RFC was never approved :-).

Now you can use the java ServerSocket port 0 feature to use any free port available on the machine.
It has been fixed with the issue 52028.

So now you can write a unit test as it (here a test with a REST service provided by Apache CXF).

    @Before
    public void startTomcat()
        throws Exception
    {
        tomcat = new Tomcat();
        tomcat.setBaseDir( System.getProperty( "java.io.tmpdir" ) );
        tomcat.setPort( 0 );

        Context context = tomcat.addContext( "", System.getProperty( "java.io.tmpdir" ) );

        A context param in your web.xml:

        <context-param>
          <param-name>contextConfigLocation</param-name>
          <param-value>classpath*:META-INF/spring-context.xml</param-value>
        </context-param>
        
        In the code

        ApplicationParameter applicationParameter = new ApplicationParameter();
        applicationParameter.setName( "contextConfigLocation" );
        applicationParameter.setValue( "classpath*:META-INF/spring-context.xml" );
        context.addApplicationParameter( applicationParameter );

        A listener class in your web.xml:

        <listener>
          <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
        </listener>

        In the code

        context.addApplicationListener( ContextLoaderListener.class.getName() );

        CXF servlet declaration in your web.xml:

        <servlet>
          <servlet-name>CXFServlet</servlet-name>
          <servlet-class>org.apache.cxf.transport.servlet.CXFServlet</servlet-class>
       </servlet>

       <servlet-mapping>
         <servlet-name>CXFServlet</servlet-name>
         <url-pattern>/restServices/*</url-pattern>
       </servlet-mapping>

       In the code:

       tomcat.addServlet( context, "cxf", new CXFServlet() );
       context.addServletMapping( "/restServices/*", "cxf" );

        tomcat.start();

        port = tomcat.getConnector().getLocalPort();

        System.out.println("Tomcat started on port:"+port);
    }

So now you can test/consume you REST services on localhost with the port.

Don't miss to shutdown the tomcat instance on tearDown or @After

    @After
    public void stopTomcat()
        throws Exception
    {
        tomcat.stop();
    }

If you use Maven you need the following dependencies:

    <dependency>
      <groupId>org.apache.tomcat.embed</groupId>
      <artifactId>tomcat-embed-core</artifactId>
      <scope>test</scope>
      <version>7.0.25</version>
    </dependency>
    <dependency>
      <groupId>org.apache.tomcat</groupId>
      <artifactId>tomcat-juli</artifactId>
      <scope>test</scope>
      <version>7.0.25</version>
    </dependency>
    <dependency>
      <groupId>org.apache.tomcat.embed</groupId>
      <artifactId>tomcat-embed-logging-juli</artifactId>
      <scope>test</scope>
      <version>7.0.25</version>
    </dependency>
    <dependency>
      <groupId>org.apache.tomcat</groupId>
      <artifactId>tomcat-servlet-api</artifactId>
      <scope>test</scope>
      <version>7.0.25</version>
    </dependency>

As samples talks more than long docs ("Code talks, bullshit walks" :-) ).
The tomcat maven archetype has been improved with a sample. (see previous post)

Have Fun!