Android example source code file (PluginManager.java)

This example Android source code file (PluginManager.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, annotate, app, arraylist, can't, classloader, classnotfoundexception, content, context, logtag, namenotfoundexception, os, packageinfo, plugin_action, plugin_type, pluginmanager, signature, string, the, util

The PluginManager.java Android example source code

/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.webkit;

import java.util.ArrayList;
import java.util.List;

import android.annotation.SdkConstant;
import android.annotation.SdkConstant.SdkConstantType;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.content.pm.ServiceInfo;
import android.content.pm.Signature;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.SystemProperties;
import android.util.Log;

/**
 * Class for managing the relationship between the {@link WebView} and installed
 * plugins in the system. You can find this class through
 * {@link PluginManager#getInstance}.
 * 
 * @hide pending API solidification
 */
public class PluginManager {

    /**
     * Service Action: A plugin wishes to be loaded in the WebView must provide
     * {@link android.content.IntentFilter IntentFilter} that accepts this
     * action in their AndroidManifest.xml.
     * <p>
     * TODO: we may change this to a new PLUGIN_ACTION if this is going to be
     * public.
     */
    @SdkConstant(SdkConstantType.SERVICE_ACTION)
    public static final String PLUGIN_ACTION = "android.webkit.PLUGIN";

    /**
     * A plugin wishes to be loaded in the WebView must provide this permission
     * in their AndroidManifest.xml.
     */
    public static final String PLUGIN_PERMISSION = "android.webkit.permission.PLUGIN";

    private static final String LOGTAG = "webkit";

    private static final String PLUGIN_TYPE = "type";
    private static final String TYPE_NATIVE = "native";

    private static PluginManager mInstance = null;

    private final Context mContext;

    private ArrayList<PackageInfo> mPackageInfoCache;

    // Only plugin matches one of the signatures in the list can be loaded
    // inside the WebView process
    private static final String SIGNATURE_1 = "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";

    private static final Signature[] SIGNATURES = new Signature[] {
        new Signature(SIGNATURE_1)
    };

    private PluginManager(Context context) {
        mContext = context;
        mPackageInfoCache = new ArrayList<PackageInfo>();
    }

    public static synchronized PluginManager getInstance(Context context) {
        if (mInstance == null) {
            if (context == null) {
                throw new IllegalStateException(
                        "First call to PluginManager need a valid context.");
            }
            mInstance = new PluginManager(context.getApplicationContext());
        }
        return mInstance;
    }

    /**
     * Signal the WebCore thread to refresh its list of plugins. Use this if the
     * directory contents of one of the plugin directories has been modified and
     * needs its changes reflecting. May cause plugin load and/or unload.
     * 
     * @param reloadOpenPages Set to true to reload all open pages.
     */
    public void refreshPlugins(boolean reloadOpenPages) {
        BrowserFrame.sJavaBridge.obtainMessage(
                JWebCoreJavaBridge.REFRESH_PLUGINS, reloadOpenPages)
                .sendToTarget();
    }

    String[] getPluginDirectories() {

        ArrayList<String> directories = new ArrayList();
        PackageManager pm = mContext.getPackageManager();
        List<ResolveInfo> plugins = pm.queryIntentServices(new Intent(
                PLUGIN_ACTION), PackageManager.GET_SERVICES
                | PackageManager.GET_META_DATA);

        synchronized(mPackageInfoCache) {

            // clear the list of existing packageInfo objects
            mPackageInfoCache.clear();

            for (ResolveInfo info : plugins) {

                // retrieve the plugin's service information
                ServiceInfo serviceInfo = info.serviceInfo;
                if (serviceInfo == null) {
                    Log.w(LOGTAG, "Ignore bad plugin");
                    continue;
                }

                // retrieve information from the plugin's manifest
                PackageInfo pkgInfo;
                try {
                    pkgInfo = pm.getPackageInfo(serviceInfo.packageName,
                                    PackageManager.GET_PERMISSIONS
                                    | PackageManager.GET_SIGNATURES);
                } catch (NameNotFoundException e) {
                    Log.w(LOGTAG, "Can't find plugin: " + serviceInfo.packageName);
                    continue;
                }
                if (pkgInfo == null) {
                    continue;
                }

                // check if their is a conflict in the lib directory names
                String directory = pkgInfo.applicationInfo.dataDir + "/lib";
                if (directories.contains(directory)) {
                    continue;
                }

                // check if the plugin has the required permissions
                String permissions[] = pkgInfo.requestedPermissions;
                if (permissions == null) {
                    continue;
                }
                boolean permissionOk = false;
                for (String permit : permissions) {
                    if (PLUGIN_PERMISSION.equals(permit)) {
                        permissionOk = true;
                        break;
                    }
                }
                if (!permissionOk) {
                    continue;
                }

                // check to ensure the plugin is properly signed
                Signature signatures[] = pkgInfo.signatures;
                if (signatures == null) {
                    continue;
                }
                if (SystemProperties.getBoolean("ro.secure", false)) {
                    boolean signatureMatch = false;
                    for (Signature signature : signatures) {
                        for (int i = 0; i < SIGNATURES.length; i++) {
                            if (SIGNATURES[i].equals(signature)) {
                                signatureMatch = true;
                                break;
                            }
                        }
                    }
                    if (!signatureMatch) {
                        continue;
                    }
                }

                // determine the type of plugin from the manifest
                if (serviceInfo.metaData == null) {
                    Log.e(LOGTAG, "The plugin '" + serviceInfo.name + "' has no type defined");
                    continue;
                }

                String pluginType = serviceInfo.metaData.getString(PLUGIN_TYPE);
                if (!TYPE_NATIVE.equals(pluginType)) {
                    Log.e(LOGTAG, "Unrecognized plugin type: " + pluginType);
                    continue;
                }

                try {
                    Class<?> cls = getPluginClass(serviceInfo.packageName, serviceInfo.name);

                    //TODO implement any requirements of the plugin class here!
                    boolean classFound = true;

                    if (!classFound) {
                        Log.e(LOGTAG, "The plugin's class' " + serviceInfo.name + "' does not extend the appropriate class.");
                        continue;
                    }

                } catch (NameNotFoundException e) {
                    Log.e(LOGTAG, "Can't find plugin: " + serviceInfo.packageName);
                    continue;
                } catch (ClassNotFoundException e) {
                    Log.e(LOGTAG, "Can't find plugin's class: " + serviceInfo.name);
                    continue;
                }

                // if all checks have passed then make the plugin available
                mPackageInfoCache.add(pkgInfo);
                directories.add(directory);
            }
        }

        return directories.toArray(new String[directories.size()]);
    }

    /* package */
    String getPluginsAPKName(String pluginLib) {

        // basic error checking on input params
        if (pluginLib == null || pluginLib.length() == 0) {
            return null;
        }

        // must be synchronized to ensure the consistency of the cache
        synchronized(mPackageInfoCache) {
            for (PackageInfo pkgInfo : mPackageInfoCache) {
                if (pluginLib.startsWith(pkgInfo.applicationInfo.dataDir)) {
                    return pkgInfo.packageName;
                }
            }
        }

        // if no apk was found then return null
        return null;
    }

    String getPluginSharedDataDirectory() {
        return mContext.getDir("plugins", 0).getPath();
    }

    /* package */
    Class<?> getPluginClass(String packageName, String className)
            throws NameNotFoundException, ClassNotFoundException {
        Context pluginContext = mContext.createPackageContext(packageName,
                Context.CONTEXT_INCLUDE_CODE |
                Context.CONTEXT_IGNORE_SECURITY);
        ClassLoader pluginCL = pluginContext.getClassLoader();
        return pluginCL.loadClass(className);
    }
}