Jetty 9 The absolute uri: http://java.sun.com/jsp/jstl/core cannot be resolved

Question

I\'m using

• Jetty 9 embedded.
• Maven
• Java 1.7
• JSTL

When I run my app in Eclipse and browse to my webpage which contain

Answer 1

You should use:

    <dependency>
        <groupId>org.eclipse.jetty</groupId>
        <artifactId>apache-jstl</artifactId>
        <version>${jetty-version}</version>
    </dependency>

Instead of:

 <dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>jstl</artifactId>
    <version>1.2</version>
</dependency>

I also meet same problem but it was blown after I make that change.

Answer 2

I've run into the same problem but found no answer recently. I had to debug glassfish code to solve it. I hope the following explanation can help others.

About dependencies, to run with JSP with glassfish you will need:

<dependency>
    <groupId>org.eclipse.jetty</groupId>
    <artifactId>jetty-jsp</artifactId>
    <version>9.2.3.v20140905</version>
</dependency>

<dependency>
    <groupId>org.eclipse.jetty.toolchain</groupId>
    <artifactId>jetty-jsp-jdt</artifactId>
    <version>2.3.3</version>
</dependency>

The reason why your embedded Jetty could not load core even if you have a jar of JSLT 1.2 (propably javax.servlet.jsp.jstl.jar from glassfish) is because of TldScanner class including in glassfish jars for JSP. To be clear this class has some static like:

197    static {
198        systemUrisJsf.add("http://java.sun.com/jsf/core");
199        systemUrisJsf.add("http://java.sun.com/jsf/html");
200        systemUris.add("http://java.sun.com/jsp/jstl/core");
201    }

And it would not load TLD in the JAR because of the block in

515    private void mapTldLocation(String resourcePath, TldInfo tldInfo,
516                                boolean isLocal) {
517
518        String uri = tldInfo.getUri();
519        if (uri == null) {
520            return;
521        }
522
523        if ((isLocal
524                // Local tld files override the tlds in the jar files,
525                // unless it is in a system jar (except when using myfaces)
526                && mappings.get(uri) == null
527                && !systemUris.contains(uri)
528                && (!systemUrisJsf.contains(uri) || useMyFaces)
529            ) ||
530            (!isLocal
531                // Jars are scanned bottom up, so jars in WEB-INF override
532                // thos in the system (except when using myfaces)
533                && (mappings.get(uri) == null
534                    || systemUris.contains(uri)
535                    || (systemUrisJsf.contains(uri) && !useMyFaces)
536                   )
537            )
538           ) {
            ...

There is no way it's gonna load your TLD if the url is "http://java.sun.com/jsp/jstl/core" and it is stored in a local jar. To make it NOT LOCAL, the application must be loaded by a class loader whose parent contains the JSTL jar. In short, you need to modify code to initialize WebAppContext as something like:

  ...
  WebAppContext webapp = new WebAppContext();

  // classURLs may contains URL to WEB-INF/classes or WEB-INF/lib/additional_jar of you web app
  URLClassLoader classLoader = new URLClassLoader(classURLs.toArray(new URL[classURLs.size()]),
        Thread.currentThread().getContextClassLoader());
    webapp.setClassLoader(classLoader);
  ...
  ContextHandlerCollection contextCollection = new ContextHandlerCollection();
  contextCollection.addHandler(webapp);
  ...
  Server server = new Server(threadPool);
  server.setHandler(contextCollection);
  server.start();
  ...

If this does not help, I'd like to learn how you embed Jetty in you application.

Answer 3

You have a conflicting / duplicate artifact for JSTL.

Simplify your dependencies.

<dependencies>
  <!-- Meta Dependency - adds JSP support to the same version of Jetty -->
  <dependency>
    <groupId>org.eclipse.jetty</groupId>
    <artifactId>jetty-jsp</artifactId>
    <version>9.0.6.v20130930</version>
  </dependency>
  <!-- NOT NEEDED
  <dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>jstl</artifactId>
    <version>1.2</version>
  </dependency> -->
  <dependency>
    <groupId>org.eclipse.jetty</groupId>
    <artifactId>jetty-webapp</artifactId>
    <version>9.0.6.v20130930</version>
  </dependency>
  <!-- NOT NEEDED
  <dependency>
    <groupId>org.mortbay.jetty</groupId>
    <artifactId>jsp-2.1-glassfish</artifactId>
    <version>2.1.v20100127</version>
 </dependency> -->
</dependency>

You can see that we don't use the JSTL artifact and org.mortbay.jetty provided jsp support level.
Jetty has provided a meta dependency to pull in the artifacts to support JSP on the same version of Jetty as your jetty-webapp artifact.