JarRsrcLoader.java

package org.eclipse.jdt.internal.jarinjarloader;

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.jar.Attributes;
import java.util.jar.Manifest;

public class JarRsrcLoader
{
  public static void main(String[] args)
    throws ClassNotFoundException, IllegalArgumentException, IllegalAccessException, InvocationTargetException, SecurityException, NoSuchMethodException, IOException
  {
    ManifestInfo mi = getManifestInfo();
    ClassLoader cl = Thread.currentThread().getContextClassLoader();
    URL.setURLStreamHandlerFactory(new RsrcURLStreamHandlerFactory(cl));
    URL[] rsrcUrls = new URL[mi.rsrcClassPath.length];
    for (int i = 0; i < mi.rsrcClassPath.length; i++) {
      String rsrcPath = mi.rsrcClassPath[i];
      if (rsrcPath.endsWith("/"))
        rsrcUrls[i] = new URL("rsrc:" + rsrcPath);
      else
        rsrcUrls[i] = new URL("jar:rsrc:" + rsrcPath + "!/");
    }
    ClassLoader jceClassLoader = new URLClassLoader(rsrcUrls, null);
    Thread.currentThread().setContextClassLoader(jceClassLoader);
    Class c = Class.forName(mi.rsrcMainClass, true, jceClassLoader);
    Method main = c.getMethod("main", new Class[] { args.getClass() });
    main.invoke(null, new Object[] { args });
  }

  private static ManifestInfo getManifestInfo() throws IOException
  {
    Enumeration resEnum = Thread.currentThread().getContextClassLoader().getResources("META-INF/MANIFEST.MF");
    while (resEnum.hasMoreElements()) {
      try {
        URL url = (URL)resEnum.nextElement();
        InputStream is = url.openStream();
        if (is != null) {
          ManifestInfo result = new ManifestInfo(null);
          Manifest manifest = new Manifest(is);
          Attributes mainAttribs = manifest.getMainAttributes();
          result.rsrcMainClass = mainAttribs.getValue("Rsrc-Main-Class");
          String rsrcCP = mainAttribs.getValue("Rsrc-Class-Path");
          if (rsrcCP == null)
            rsrcCP = "";
          result.rsrcClassPath = splitSpaces(rsrcCP);
          if ((result.rsrcMainClass != null) && (!result.rsrcMainClass.trim().equals("")))
            return result;
        }
      }
      catch (Exception localException)
      {
      }
    }
    System.err.println("Missing attributes for JarRsrcLoader in Manifest (Rsrc-Main-Class, Rsrc-Class-Path)");
    return null;
  }

  private static String[] splitSpaces(String line)
  {
    if (line == null)
      return null;
    List result = new ArrayList();
    int firstPos = 0;
    while (firstPos < line.length()) {
      int lastPos = line.indexOf(' ', firstPos);
      if (lastPos == -1)
        lastPos = line.length();
      if (lastPos > firstPos) {
        result.add(line.substring(firstPos, lastPos));
      }
      firstPos = lastPos + 1;
    }
    return (String[])result.toArray(new String[result.size()]);
  }

  private static class ManifestInfo
  {
    String rsrcMainClass;
    String[] rsrcClassPath;

    private ManifestInfo()
    {
    }

    ManifestInfo(ManifestInfo paramManifestInfo)
    {
      this();
    }
  }
}