1 files changed, 76 insertions, 0 deletions
diff --git a/mobile/android/annotations/src/main/java/org/mozilla/gecko/annotationProcessors/classloader/IterableJarLoadingURLClassLoader.java b/mobile/android/annotations/src/main/java/org/mozilla/gecko/annotationProcessors/classloader/IterableJarLoadingURLClassLoader.java
new file mode 100644
index 0000000000..50200ef3ec
--- /dev/null
+++ b/mobile/android/annotations/src/main/java/org/mozilla/gecko/annotationProcessors/classloader/IterableJarLoadingURLClassLoader.java
@@ -0,0 +1,76 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.annotationProcessors.classloader;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+
+/**
+ * A classloader which can be initialised with a list of jar files and which can provide an iterator
+ * over the top level classes in the jar files it was initialised with. classNames is kept sorted to
+ * ensure iteration order is consistent across program invocations. Otherwise, we'd forever be
+ * reporting the outdatedness of the generated code as we permute its contents.
+ */
+public class IterableJarLoadingURLClassLoader extends URLClassLoader {
+  LinkedList<String> classNames = new LinkedList<String>();
+
+  /**
+   * Create an instance and return its iterator. Provides an iterator over the classes in the jar
+   * files provided as arguments. Inner classes are not supported.
+   *
+   * @param args A list of jar file names an iterator over the classes of which is desired.
+   * @return An iterator over the top level classes in the jar files provided, in arbitrary order.
+   */
+  public static Iterator<ClassWithOptions> getIteratorOverJars(String[] args) {
+    URL[] urlArray = new URL[args.length];
+    LinkedList<String> aClassNames = new LinkedList<String>();
+
+    for (int i = 0; i < args.length; i++) {
+      try {
+        urlArray[i] = (new File(args[i])).toURI().toURL();
+
+        Enumeration<JarEntry> entries = new JarFile(args[i]).entries();
+        while (entries.hasMoreElements()) {
+          JarEntry e = entries.nextElement();
+          String fName = e.getName();
+          if (!fName.endsWith(".class")) {
+            continue;
+          }
+          final String className = fName.substring(0, fName.length() - 6).replace('/', '.');
+
+          aClassNames.add(className);
+        }
+      } catch (IOException e) {
+        System.err.println("Error loading jar file \"" + args[i] + '"');
+        e.printStackTrace(System.err);
+      }
+    }
+    Collections.sort(aClassNames);
+    return new JarClassIterator(new IterableJarLoadingURLClassLoader(urlArray, aClassNames));
+  }
+
+  /**
+   * Constructs a classloader capable of loading all classes given as URLs in urls. Used by static
+   * method above.
+   *
+   * @param urls URLs for all classes the new instance shall be capable of loading.
+   * @param aClassNames A list of names of the classes this instance shall be capable of loading.
+   */
+  protected IterableJarLoadingURLClassLoader(
+      URL[] urls,
+      LinkedList<String>
+          aClassNames) { // Array to populate with URLs for each class in the given jars.
+    super(urls);
+    classNames = aClassNames;
+  }
+}