Jetty/Feature/JNDI

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Contents

Introduction

Jetty supports java:comp/env lookups in webapps. This is an optional feature, and as such some setup needs to be done. However, if you're using the [Hightide] distribution of jetty, then this feature is already fully enabled for you, so you can skip any setup steps, and read the section on how to put objects into jetty's JNDI so that you can retrieve them at runtime.

Feature

Setup

Deployment-time configuration

Skip this step if you are using the Hightide distribution of jetty as JNDI is automatically enabled for you. For non-Hightide distributions, you may enable JNDI either for a particular web app or you can enable it by default for all webapps. In either case, we need to re-define the list of configurations that can be applied to a WebAppContext on deployment:

<Array id="plusConfig" type="java.lang.String">
  <Item>org.eclipse.jetty.webapp.WebInfConfiguration</Item>
  <Item>org.eclipse.jetty.webapp.WebXmlConfiguration</Item>
  <Item>org.eclipse.jetty.webapp.MetaInfConfiguration</Item>
  <Item>org.eclipse.jetty.webapp.FragmentConfiguration</Item>
  <Item>org.eclipse.jetty.plus.webapp.EnvConfiguration</Item> <!-- add -->
  <Item>org.eclipse.jetty.plus.webapp.Configuration</Item>    <!-- add -->
  <Item>org.eclipse.jetty.webapp.JettyWebXmlConfiguration</Item>
  <Item>org.eclipse.jetty.webapp.TagLibConfiguration</Item>
</Array>

Now, to apply this to a single webapp, we create a context xml file that describes the setup of that particular webapp and instruct it to apply these special configurations on deployment:

<Configure id='wac' class="org.eclipse.jetty.webapp.WebAppContext">
 
  <Array id="plusConfig" type="java.lang.String">
    <Item>org.eclipse.jetty.webapp.WebInfConfiguration</Item>
    <Item>org.eclipse.jetty.webapp.WebXmlConfiguration</Item>
    <Item>org.eclipse.jetty.webapp.MetaInfConfiguration</Item>
    <Item>org.eclipse.jetty.webapp.FragmentConfiguration</Item>
    <Item>org.eclipse.jetty.plus.webapp.EnvConfiguration</Item> <!-- add for JNDI -->
    <Item>org.eclipse.jetty.plus.webapp.Configuration</Item>    <!-- add for JNDI -->
    <Item>org.eclipse.jetty.webapp.JettyWebXmlConfiguration</Item>
    <Item>org.eclipse.jetty.webapp.TagLibConfiguration</Item>
  </Array>
 
  <Set name="war"><SystemProperty name="jetty.home" default="."/>/webapps/my-cool-webapp</Set>
  <Set name="configurationClasses"><Ref id="plusConfig"/></Set>
 
</Configure>

Alternatively, we could apply these configurations to every webapp that is deployed. To do that, we edit the $JETTY_HOME/etc/jetty.xml file (or create a new new file and put it on the runline or put it in start.ini) to add:

<Configure id="Server" class="org.eclipse.jetty.server.Server">
 
    <Call name="setAttribute">
      <Arg>org.eclipse.jetty.webapp.configuration</Arg>
      <Arg>
          <Array type="java.lang.String">
              <Item>org.eclipse.jetty.webapp.WebInfConfiguration</Item>
              <Item>org.eclipse.jetty.webapp.WebXmlConfiguration</Item>
              <Item>org.eclipse.jetty.webapp.MetaInfConfiguration</Item>
              <Item>org.eclipse.jetty.webapp.FragmentConfiguration</Item>
              <Item>org.eclipse.jetty.plus.webapp.EnvConfiguration</Item>
              <Item>org.eclipse.jetty.plus.webapp.Configuration</Item>
              <Item>org.eclipse.jetty.webapp.JettyWebXmlConfiguration</Item>
              <Item>org.eclipse.jetty.webapp.TagLibConfiguration</Item>
          </Array>
      </Arg>
    </Call>
</Configure>
Idea.png
Tip:
We have included the etc/jetty-plus.xml configuration file that configures a WebAppDeployer to deploy all webapps in the webapps-plus directory with JNDI. You can modify this file as desired, or merge it with your etc/jetty.xml file.


Classpath jars

Now that we have the JNDI configuration for the webapp(s) set up, we need to ensure that the JNDI implementation jars are on jetty's classpath. These jars are optional, so won't be there by default. We add these into the classpath by using startup time OPTIONS:

java -jar start.jar OPTIONS=plus
Idea.png
Tip:
If you prefer, you can edit the start.ini file and add "plus" to the default OPTIONS to lessen the verbosity of the runline.

You may now configure naming resources that can be referenced in a web.xml file and accessed from within the java:comp/env naming environment of the webapp during execution. Specifically, you may configure support for the following web.xml elements:

<env-entry/>
<resource-ref/>
<resource-env-ref/>

#Configuring_env-entrys shows you how to set up overrides for <env-entry> elements in web.xml. [Configuring resource-refs and resource-env-refs