If you have an embedded setup for your webapp and wish to use JSPs, you will need to ensure that a JSP engine is correctly initialized.

For Apache, a Servlet Specification 3.1 style ServletContainerInitializer is used to accomplish this. You will need to ensure that this ServletContainerInitializer is run by jetty. Perhaps the easiest way to do this is to enable annotations processing so that Jetty automatically discovers and runs it. The Embedded Examples section includes a worked code example of how to do this.

Alternatively, you can manually wire in the appropriate ServletContainerInitializer as shown in the embedded-jetty-jsp example on GitHub, in which case you will not need the jetty-annotations jar on your classpath, nor include the AnnotationConfiguration in the list of configuration classes.

By default, the Apache JSP container will look for the Eclipse Java Compiler (jdt). The Jetty distribution ships a copy of this in {$jetty.home}/lib/apache-jsp. If you wish to use a different compiler, you will need to configure the compilerClassName init-param on the JspServlet with the name of the class.

The JSP engine has many configuration parameters. Some parameters affect only precompilation, and some affect runtime recompilation checking. Parameters also differ among the various versions of the JSP engine. This page lists the configuration parameters, their meanings, and their default settings. Set all parameters on the org.apache.jasper.JspServlet instance defined in the webdefault.xml file.

You can make a copy of the {$jetty.home}/etc/webdefault.xml that ships with Jetty, apply your changes, and use it instead of the shipped version. The example below shows how to do this when using the Jetty Maven plugin.

  <plugin>
    <groupId>org.eclipse.jetty</groupId>
    <artifactId>jetty-maven-plugin</artifactId>
    <configuration>
      <webApp>
        <defaultsDescriptor>src/main/resources/webdefault.xml</defaultsDescriptor>
      </webApp>
  </plugin>

If you are using the Jetty distribution, and you want to change the JSP settings for just one or a few of your webapps, copy the {$jetty.home}/etc/webdefault.xml file somewhere, modify it, and then use a context xml file to set this file as the defaultsDescriptor for your webapp. Here’s a snippet:

 <Configure class=>"org.eclipse.jetty.webapp.WebAppContext">

   <Set name=>"contextPath">/foo</Set>
   <Set name=>"war"><SystemProperty name=>"jetty.home" >default=>"."/>/webapps/foobar.war</Set>
   <Set name=>"defaultsDescriptor">/home/smith/dev/webdefault.xml</Set>

 </Configure>

If you want to change the JSP settings for all webapps, edit the {$jetty.home}/etc/webdefaults.xml file directly instead.

Another option is to add an entry for the JSPServlet to the WEB-INF/web.xml file of your webapp and change or add init-params. You may also add (but not remove) servlet-mappings. You can use the entry in {$jetty.home}/etc/webdefault.xml as a starting point.

 <servlet id="jsp">
     <servlet-name>jsp</servlet-name>
     <servlet-class>org.apache.jasper.servlet.JspServlet</servlet-class>
     <init-param>
         <param-name>logVerbosityLevel</param-name>
         <param-value>DEBUG</param-value>
     </init-param>
     <init-param>
         <param-name>fork</param-name>
         <param-value>>false</param-value>
     </init-param>
     <init-param>
         <param-name>keepgenerated</param-name>
         <param-value>>true</param-value>
     </init-param>
     ...

     <load-on-startup>0</load-on-startup>
   </servlet>

   <servlet-mapping>
     <servlet-name>jsp</servlet-name>
     <url-pattern>*.jsp</url-pattern>
     <url-pattern>*.jspf</url-pattern>
     <url-pattern>*.jspx</url-pattern>
     <url-pattern>*.xsp</url-pattern>
     <url-pattern>*.JSP</url-pattern>
     <url-pattern>*.JSPF</url-pattern>
     <url-pattern>*.JSPX</url-pattern>
     <url-pattern>*.XSP</url-pattern>
   </servlet-mapping>

   <servlet id="my-servlet">
     <servlet-name>myServlet</servlet-name>
     <servlet-class>com.acme.servlet.MyServlet</servlet-class>
      ...

By default, Jetty does not enable async support for the JSP servlet. Configuring the JSP servlet for async is relatively easy - simply define the async-supported parameter as true in either your webdefault.xml or the web.xml for a specific context.

<servlet id="jsp">
  <servlet-name>jsp</servlet-name>
  <async-supported>true</async-supported>
</servlet>

If you are using Jetty in an embedded scenario, and you need to use JSTL, then you must ensure that the JSTL jars are included on the container’s classpath - that is the classpath that is the parent of the webapp’s classpath. This is a restriction that arises from the JavaEE specification.

  webapp.setAttribute("org.eclipse.jetty.server.webapp.ContainerIncludeJarPattern",".*/[^/]*taglibs.*\\.jar$");

If you want to use JSF with your webapp, you need to copy the JSF implementation Jar (whichever Jar contains the META-INF/*.tld files from your chosen JSF implementation) into Jetty’s shared container lib directory. You can either put them into the lib directory for Apache {$jetty.home}/lib/apache-jsp or put them into {$jetty.home}/lib/ext.

You should make your JSF jars dependencies of the plugin and not the webapp itself. For example:

   <plugin>
    <groupId>org.eclipse.jetty</groupId>
    <artifactId>jetty-maven-plugin</artifactId>
    <configuration>
       <webApp>
         <contextPath>/${artifactId}</contextPath>
       </webApp>
       <scanIntervalSeconds>5</scanIntervalSeconds>
    </configuration>
    <dependencies>
      <dependency>
        <groupId>com.sun.faces</groupId>
        <artifactId>jsf-api</artifactId>
        <version>2.0.8</version>
      </dependency>
      <dependency>
        <groupId>com.sun.faces</groupId>
        <artifactId>jsf-impl</artifactId>
        <version>2.0.8</version>
     </dependency>
    </dependencies>
  </plugin>