Java content handler for Android.

services/android/java/src/org/chromium/services/android/JavaHandler.java

Index: services/android/java/src/org/chromium/services/android/JavaHandler.java
diff --git a/services/android/java/src/org/chromium/services/android/JavaHandler.java b/services/android/java/src/org/chromium/services/android/JavaHandler.java
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index 0000000000000000000000000000000000000000..7abdcf402c93245bdd87314e36e310585097d2d7
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+++ b/services/android/java/src/org/chromium/services/android/JavaHandler.java
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+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.services.android;
+
+import android.content.Context;
+import android.util.Log;
+
+import dalvik.system.DexClassLoader;
+
+import org.chromium.base.CalledByNative;
+import org.chromium.base.JNINamespace;
+import org.chromium.mojo.system.Core;
+import org.chromium.mojo.system.MessagePipeHandle;
+import org.chromium.mojo.system.impl.CoreImpl;
+
+import java.io.File;
+import java.io.IOException;
+import java.lang.reflect.Method;
+import java.util.jar.JarFile;
+import java.util.jar.Manifest;
+
+/**
+ * Content handler for Android Java code.
+ */
+@JNINamespace("services::android")
+public class JavaHandler {
+    private static final String TAG = "JavaHandler";
+
+    // File extensions used to identify application libraries in the provided
+    // archive.
+    private static final String JAVA_LIBRARY_SUFFIX = ".dex.jar";
+    // Filename sections used for naming temporary files holding application
+    // files.
+    private static final String ARCHIVE_PREFIX = "archive";
+
+    // Directories used to hold temporary files. These are cleared when
+    // clearTemporaryFiles() is called.
+    private static final String DEX_OUTPUT_DIRECTORY = "dex_output";
+    private static final String APP_DIRECTORY = "applications";
+
+    private static final int BUFFER_SIZE = 1024;
+
+    /**
+     * Deletes directories holding the temporary files.
+     */
+    private static void clearTemporaryFiles(Context context, File archive) {
+        deleteRecursively(getDexOutputDir(context));
+        deleteRecursively(archive);
+    }
+
+    /**
+     * Deletes a file or directory. Directory will be deleted even if not empty.
+     */
+    private static void deleteRecursively(File file) {
+        if (file.isDirectory()) {
+            for (File child : file.listFiles()) {
+                deleteRecursively(child);
+            }
+        }
+        file.delete();
+    }
+
+    /**
+     * Returns the path at which the native part should save the application archive.
+     */
+    @CalledByNative
+    private static String getNewTempLibraryPath(Context context) throws IOException {
+        return File.createTempFile(ARCHIVE_PREFIX, JAVA_LIBRARY_SUFFIX, getAppDir(context))
+                .getAbsolutePath();
+    }
+
+    /**
+     * Extracts and runs the application libraries contained by the indicated archive.
+     *
+     * @param context the application context
+     * @param archivePath the path of the archive containing the application to be run
+     * @param handle handle to the shell to be passed to the native application. On the Java side
+     *        this is opaque payload.
+     * @param runApplicationPtr pointer to the function that will set the native thunks and call
+     *        into the application MojoMain. On the Java side this is opaque payload.
+     */
+    @CalledByNative
+    private static boolean bootstrap(Context context, String archivePath,
+            int applicationRequestHandle) {
+        File application_java_library = new File(archivePath);
+
+        String dexPath = application_java_library.getAbsolutePath();
+        DexClassLoader bootstrapLoader = new DexClassLoader(dexPath,
+                getDexOutputDir(context).getAbsolutePath(), null,
+                JavaHandler.class.getClassLoader());
+
+        // The starting Mojo class is a class implementing a static MojoMain
+        // method. Its name
+        // is defined in the .jar manifest file, like a .jar defines a
+        // Main-Class attribute for
+        // the starting point of a standalone java application.
+        String mojoClass;
+        try {
+            try {
+                JarFile jar = new JarFile(application_java_library);
+                Manifest manifest = jar.getManifest();
+                mojoClass = manifest.getMainAttributes().getValue("Mojo-Class");
+            } catch (IOException e) {
+                Log.e(TAG, "Unable to extract Manifest attributes", e);
+                return false;
+            }
+
+            if (mojoClass == null) {
+                Log.e(TAG, "Mojo-Class class not found");
+                return false;
+            }
+
+            Core core = CoreImpl.getInstance();
+            MessagePipeHandle handle =
+                    core.acquireNativeHandle(applicationRequestHandle).toMessagePipeHandle();
+            try {
+                Class<?> loadedClass = bootstrapLoader.loadClass(mojoClass);
+                Method mojoMain =
+                        loadedClass.getMethod("mojoMain", Context.class, Core.class,
+                                MessagePipeHandle.class);
+                mojoMain.invoke(null, context, core, handle);
+            } catch (Throwable t) {
+                Log.e(TAG, "Running MojoMain failed.", t);
+                return false;
+            }
+        } finally {
+            clearTemporaryFiles(context, application_java_library);
+        }
+        return true;
+    }
+
+    private static File getDexOutputDir(Context context) {
+        return context.getDir(DEX_OUTPUT_DIRECTORY, Context.MODE_PRIVATE);
+    }
+
+    private static File getAppDir(Context context) {
+        return context.getDir(APP_DIRECTORY, Context.MODE_PRIVATE);
+    }
+}