Gemini Web 2.2.7 NPE

Demonstration of NullPointerException in Gemini Web 2.2.7 when adding a bundle fragment to a web application bundle. The problem arises when the fragment bundle introduces a class in a package that doesn't exist in the host bundle. For example, if in the host bundle there is a servlet in package test:

package test;

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/hello")
public class HostHello extends HttpServlet {
	@Override
	public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
		PrintWriter writer = response.getWriter();
		writer.println("<html>Hello, world!</html>");
		writer.flush();
	}
}

And then in the fragment bundle a servlet in package test.frag:

package test.frag;

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/hello-frag")
public class FragHello extends HttpServlet {
	@Override
	public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
		PrintWriter writer = response.getWriter();
		writer.println("<html>Hello, fragment!</html>");
		writer.flush();
	}
}

Then on startup Gemini Web will throw a NullPointerException:

Caused by: java.lang.NullPointerException
	at org.eclipse.gemini.web.tomcat.internal.loading.BundleEntry.isDirectory(BundleEntry.java:231)
	at org.eclipse.gemini.web.tomcat.internal.loading.BundleDirContext.entryToResult(BundleDirContext.java:118)
	at org.eclipse.gemini.web.tomcat.internal.loading.BundleDirContext.entryToResult(BundleDirContext.java:113)
	at org.eclipse.gemini.web.tomcat.internal.loading.BundleDirContext.doList(BundleDirContext.java:106)
	at org.eclipse.gemini.web.tomcat.internal.loading.BundleDirContext.doSafeList(BundleDirContext.java:89)
	at org.eclipse.gemini.web.tomcat.internal.loading.BundleDirContext.doListBindings(BundleDirContext.java:59)
	at org.apache.naming.resources.BaseDirContext.list(BaseDirContext.java:707)
	at org.apache.naming.resources.DirContextURLConnection.list(DirContextURLConnection.java:432)
	at org.apache.catalina.startup.ContextConfig.processAnnotationsJndi(ContextConfig.java:2013)
	at org.apache.catalina.startup.ContextConfig.processAnnotationsUrl(ContextConfig.java:1933)
	at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1311)
	at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:889)
	at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:386)
	at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
	at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
	at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5416)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
	...

Looking in BundleDirContext:118, a url property is null for the BundleEntry describing the test.frag package directory (described as BundleEntry [bundle=gemini-web-npe-host_1.0.0 [177],path=WEB-INF/classes/test/frag/]).

The NPE does not occur if the FragHello servlet is moved into the test package.

This repository contains two Eclipse PDE projects that expect Gemini Web to be provided by the PDE target runtime. Launch the runtime to see the NPE thrown during startup. I have submitted bug 501935 to Eclipse. I have also developed a patch that fixes the problem for my use case.

msqr/gemini-web-fragment-npe

Gemini Web 2.2.7 NPE