Setting HTTP headers with Jetty

What's the best way to set HTTP headers (based on filename patterns) in Jetty 6.1? Is it possible via jetty.xml (or jetty-web.xml)? Or do I have to modify web.xml?

You can add headers by configuration. In jetty.xml, put the following example :

<New id="RewriteHandler" class="org.eclipse.jetty.rewrite.handler.RewriteHandler">
  <Set name="rules">
    <Array type="org.eclipse.jetty.rewrite.handler.Rule">
      
      <Item>
        <New id="header" class="org.eclipse.jetty.rewrite.handler.HeaderPatternRule">
          <Set name="pattern">*.jsp</Set>
          <Set name="name">myheader</Set>
          <Set name="value">the value of myheader</Set>
        </New>
      </Item>
      
    </Array>
  </Set>
</New>

<Set name="handler">
  <New id="Handlers" class="org.eclipse.jetty.server.handler.HandlerCollection">
    <Set name="handlers">
      <Array type="org.eclipse.jetty.server.Handler">
        <Item>
          <Ref id="RewriteHandler"/>
        </Item>
      </Array>
    </Set>
  </New>
</Set>

See RewriteHandler api for more examples of what is possible (it was already available in Jetty 6 RewriteHandler)

For information, here is my maven configuration of jetty plugin :

<plugin>
  <groupId>org.mortbay.jetty</groupId>
  <artifactId>jetty-maven-plugin</artifactId>
  <version>8.1.5.v20120716</version>
  <configuration>
    <jettyXml>${basedir}/src/main/etc/jetty.xml</jettyXml>
  </configuration>
  <dependencies>
    <dependency>
      <groupId>org.eclipse.jetty</groupId>
      <artifactId>jetty-http</artifactId>
      <version>8.1.5.v20120716</version>
      <type>jar</type>
      <scope>runtime</scope>
    </dependency>
    <dependency>
      <groupId>org.eclipse.jetty</groupId>
      <artifactId>jetty-rewrite</artifactId>
      <version>8.1.5.v20120716</version>
      <type>jar</type>
      <scope>runtime</scope>
    </dependency>
  </dependencies>
</plugin>