michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: package org.mozilla.gecko.annotationProcessors.classloader;
michael@0: 
michael@0: import java.io.File;
michael@0: import java.io.IOException;
michael@0: import java.net.URL;
michael@0: import java.net.URLClassLoader;
michael@0: import java.util.Collections;
michael@0: import java.util.Enumeration;
michael@0: import java.util.Iterator;
michael@0: import java.util.LinkedList;
michael@0: import java.util.jar.JarEntry;
michael@0: import java.util.jar.JarFile;
michael@0: 
michael@0: /**
michael@0:  * A classloader which can be initialised with a list of jar files and which can provide an iterator
michael@0:  * over the top level classes in the jar files it was initialised with.
michael@0:  * classNames is kept sorted to ensure iteration order is consistent across program invocations.
michael@0:  * Otherwise, we'd forever be reporting the outdatedness of the generated code as we permute its
michael@0:  * contents.
michael@0:  */
michael@0: public class IterableJarLoadingURLClassLoader extends URLClassLoader {
michael@0:     LinkedList<String> classNames = new LinkedList<String>();
michael@0: 
michael@0:     /**
michael@0:      * Create an instance and return its iterator. Provides an iterator over the classes in the jar
michael@0:      * files provided as arguments.
michael@0:      * Inner classes are not supported.
michael@0:      *
michael@0:      * @param args A list of jar file names an iterator over the classes of which is desired.
michael@0:      * @return An iterator over the top level classes in the jar files provided, in arbitrary order.
michael@0:      */
michael@0:     public static Iterator<ClassWithOptions> getIteratorOverJars(String[] args) {
michael@0:         URL[] urlArray = new URL[args.length];
michael@0:         LinkedList<String> aClassNames = new LinkedList<String>();
michael@0: 
michael@0:         for (int i = 0; i < args.length; i++) {
michael@0:             try {
michael@0:                 urlArray[i] = (new File(args[i])).toURI().toURL();
michael@0: 
michael@0:                 Enumeration<JarEntry> entries = new JarFile(args[i]).entries();
michael@0:                 while (entries.hasMoreElements()) {
michael@0:                     JarEntry e = entries.nextElement();
michael@0:                     String fName = e.getName();
michael@0:                     if (!fName.endsWith(".class")) {
michael@0:                         continue;
michael@0:                     }
michael@0:                     final String className = fName.substring(0, fName.length() - 6).replace('/', '.');
michael@0: 
michael@0:                     aClassNames.add(className);
michael@0:                 }
michael@0:             } catch (IOException e) {
michael@0:                 System.err.println("Error loading jar file \"" + args[i] + '"');
michael@0:                 e.printStackTrace(System.err);
michael@0:             }
michael@0:         }
michael@0:         Collections.sort(aClassNames);
michael@0:         return new JarClassIterator(new IterableJarLoadingURLClassLoader(urlArray, aClassNames));
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Constructs a classloader capable of loading all classes given as URLs in urls. Used by static
michael@0:      * method above.
michael@0:      *
michael@0:      * @param urls        URLs for all classes the new instance shall be capable of loading.
michael@0:      * @param aClassNames A list of names of the classes this instance shall be capable of loading.
michael@0:      */
michael@0:     protected IterableJarLoadingURLClassLoader(URL[] urls, LinkedList<String> aClassNames) {// Array to populate with URLs for each class in the given jars.
michael@0:         super(urls);
michael@0:         classNames = aClassNames;
michael@0:     }
michael@0: }