Android example source code file (Bmgr.java)

This example Android source code file (Bmgr.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, app, application, bmgr, bmgr_not_running_err, could, error, ibackupmanager, interruptedexception, irestoresession, is, numberformatexception, os, remoteexception, restoreobserver, restoreset, string, transport_not_running_err

The Bmgr.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 com.android.commands.bmgr;

import android.app.backup.RestoreSet;
import android.app.backup.IBackupManager;
import android.app.backup.IRestoreObserver;
import android.app.backup.IRestoreSession;
import android.os.RemoteException;
import android.os.ServiceManager;

public final class Bmgr {
    IBackupManager mBmgr;
    IRestoreSession mRestore;

    static final String BMGR_NOT_RUNNING_ERR =
            "Error: Could not access the Backup Manager.  Is the system running?";
    static final String TRANSPORT_NOT_RUNNING_ERR =
        "Error: Could not access the backup transport.  Is the system running?";

    private String[] mArgs;
    private int mNextArg;
    private String mCurArgData;

    public static void main(String[] args) {
        try {
            new Bmgr().run(args);
        } catch (Exception e) {
            System.err.println("Exception caught:");
            e.printStackTrace();
        }
    }

    public void run(String[] args) {
        boolean validCommand = false;
        if (args.length < 1) {
            showUsage();
            return;
        }

        mBmgr = IBackupManager.Stub.asInterface(ServiceManager.getService("backup"));
        if (mBmgr == null) {
            System.err.println(BMGR_NOT_RUNNING_ERR);
            return;
        }

        mArgs = args;
        String op = args[0];
        mNextArg = 1;

        if ("enabled".equals(op)) {
            doEnabled();
            return;
        }

        if ("enable".equals(op)) {
            doEnable();
            return;
        }

        if ("run".equals(op)) {
            doRun();
            return;
        }

        if ("backup".equals(op)) {
            doBackup();
            return;
        }

        if ("list".equals(op)) {
            doList();
            return;
        }

        if ("restore".equals(op)) {
            doRestore();
            return;
        }

        if ("transport".equals(op)) {
            doTransport();
            return;
        }

        if ("wipe".equals(op)) {
            doWipe();
            return;
        }

        System.err.println("Unknown command");
        showUsage();
    }

    private String enableToString(boolean enabled) {
        return enabled ? "enabled" : "disabled";
    }

    private void doEnabled() {
        try {
            boolean isEnabled = mBmgr.isBackupEnabled();
            System.out.println("Backup Manager currently "
                    + enableToString(isEnabled));
        } catch (RemoteException e) {
            System.err.println(e.toString());
            System.err.println(BMGR_NOT_RUNNING_ERR);
        }
    }

    private void doEnable() {
        String arg = nextArg();
        if (arg == null) {
            showUsage();
            return;
        }

        try {
            boolean enable = Boolean.parseBoolean(arg);
            mBmgr.setBackupEnabled(enable);
            System.out.println("Backup Manager now " + enableToString(enable));
        } catch (NumberFormatException e) {
            showUsage();
            return;
        } catch (RemoteException e) {
            System.err.println(e.toString());
            System.err.println(BMGR_NOT_RUNNING_ERR);
        }
    }

    private void doRun() {
        try {
            mBmgr.backupNow();
        } catch (RemoteException e) {
            System.err.println(e.toString());
            System.err.println(BMGR_NOT_RUNNING_ERR);
        }
    }

    private void doBackup() {
        boolean isFull = false;
        String pkg = nextArg();
        if ("-f".equals(pkg)) {
            isFull = true;
            pkg = nextArg();
        }

        if (pkg == null || pkg.startsWith("-")) {
            showUsage();
            return;
        }

        try {
            // !!! TODO: handle full backup
            mBmgr.dataChanged(pkg);
        } catch (RemoteException e) {
            System.err.println(e.toString());
            System.err.println(BMGR_NOT_RUNNING_ERR);
        }
    }

    private void doTransport() {
        try {
            String which = nextArg();
            String old = mBmgr.selectBackupTransport(which);
            if (old == null) {
                System.out.println("Unknown transport '" + which
                        + "' specified; no changes made.");
            } else {
                System.out.println("Selected transport " + which + " (formerly " + old + ")");
            }
        } catch (RemoteException e) {
            System.err.println(e.toString());
            System.err.println(BMGR_NOT_RUNNING_ERR);
        }
    }

    private void doWipe() {
        String pkg = nextArg();
        if (pkg == null) {
            showUsage();
            return;
        }

        try {
            mBmgr.clearBackupData(pkg);
            System.out.println("Wiped backup data for " + pkg);
        } catch (RemoteException e) {
            System.err.println(e.toString());
            System.err.println(BMGR_NOT_RUNNING_ERR);
        }
    }

    private void doList() {
        String arg = nextArg();     // sets, transports, packages set#
        if ("transports".equals(arg)) {
            doListTransports();
            return;
        }

        // The rest of the 'list' options work with a restore session on the current transport
        try {
            String curTransport = mBmgr.getCurrentTransport();
            mRestore = mBmgr.beginRestoreSession(curTransport);
            if (mRestore == null) {
                System.err.println(BMGR_NOT_RUNNING_ERR);
                return;
            }

            if ("sets".equals(arg)) {
                doListRestoreSets();
            } else if ("transports".equals(arg)) {
                doListTransports();
            }

            mRestore.endRestoreSession();
        } catch (RemoteException e) {
            System.err.println(e.toString());
            System.err.println(BMGR_NOT_RUNNING_ERR);
        }
    }

    private void doListTransports() {
        try {
            String current = mBmgr.getCurrentTransport();
            String[] transports = mBmgr.listAllTransports();
            if (transports == null || transports.length == 0) {
                System.out.println("No transports available.");
                return;
            }

            for (String t : transports) {
                String pad = (t.equals(current)) ? "  * " : "    ";
                System.out.println(pad + t);
            }
        } catch (RemoteException e) {
            System.err.println(e.toString());
            System.err.println(BMGR_NOT_RUNNING_ERR);
        }
    }

    private void doListRestoreSets() {
        try {
            RestoreObserver observer = new RestoreObserver();
            int err = mRestore.getAvailableRestoreSets(observer);
            if (err != 0) {
                System.out.println("Unable to request restore sets");
            } else {
                observer.waitForCompletion();
                printRestoreSets(observer.sets);
            }
        } catch (RemoteException e) {
            System.err.println(e.toString());
            System.err.println(TRANSPORT_NOT_RUNNING_ERR);
        }
    }

    private void printRestoreSets(RestoreSet[] sets) {
        for (RestoreSet s : sets) {
            System.out.println("  " + Long.toHexString(s.token) + " : " + s.name);
        }
    }

    class RestoreObserver extends IRestoreObserver.Stub {
        boolean done;
        RestoreSet[] sets = null;

        public void restoreSetsAvailable(RestoreSet[] result) {
            synchronized (this) {
                sets = result;
                done = true;
                this.notify();
            }
        }

        public void restoreStarting(int numPackages) {
            System.out.println("restoreStarting: " + numPackages + " packages");
        }

        public void onUpdate(int nowBeingRestored, String currentPackage) {
            System.out.println("onUpdate: " + nowBeingRestored + " = " + currentPackage);
        }

        public void restoreFinished(int error) {
            System.out.println("restoreFinished: " + error);
            synchronized (this) {
                done = true;
                this.notify();
            }
        }

        public void waitForCompletion() {
            // The restoreFinished() callback will throw the 'done' flag; we
            // just sit and wait on that notification.
            synchronized (this) {
                while (!this.done) {
                    try {
                        this.wait();
                    } catch (InterruptedException ex) {
                    }
                }
            }
        }
    }

    private void doRestore() {
        String arg = nextArg();
        if (arg.indexOf('.') >= 0) {
            // it's a package name
            doRestorePackage(arg);
        } else {
            try {
                long token = Long.parseLong(arg, 16);
                doRestoreAll(token);
            } catch (NumberFormatException e) {
                showUsage();
                return;
            }
        }

        System.out.println("done");
    }

    private void doRestorePackage(String pkg) {
        try {
            String curTransport = mBmgr.getCurrentTransport();
            mRestore = mBmgr.beginRestoreSession(curTransport);
            if (mRestore == null) {
                System.err.println(BMGR_NOT_RUNNING_ERR);
                return;
            }

            RestoreObserver observer = new RestoreObserver();
            int err = mRestore.restorePackage(pkg, observer);
            if (err == 0) {
                // Off and running -- wait for the restore to complete
                observer.waitForCompletion();
            } else {
                System.err.println("Unable to restore package " + pkg);
            }

            // And finally shut down the session
            mRestore.endRestoreSession();
        } catch (RemoteException e) {
            System.err.println(e.toString());
            System.err.println(BMGR_NOT_RUNNING_ERR);
        }
    }

    private void doRestoreAll(long token) {
        RestoreObserver observer = new RestoreObserver();

        try {
            boolean didRestore = false;
            String curTransport = mBmgr.getCurrentTransport();
            mRestore = mBmgr.beginRestoreSession(curTransport);
            if (mRestore == null) {
                System.err.println(BMGR_NOT_RUNNING_ERR);
                return;
            }
            RestoreSet[] sets = null;
            int err = mRestore.getAvailableRestoreSets(observer);
            if (err == 0) {
                observer.waitForCompletion();
                sets = observer.sets;
                for (RestoreSet s : sets) {
                    if (s.token == token) {
                        System.out.println("Scheduling restore: " + s.name);
                        didRestore = (mRestore.restoreAll(token, observer) == 0);
                        break;
                    }
                }
            }
            if (!didRestore) {
                if (sets == null || sets.length == 0) {
                    System.out.println("No available restore sets; no restore performed");
                } else {
                    System.out.println("No matching restore set token.  Available sets:");
                    printRestoreSets(sets);
                }
            }

            // if we kicked off a restore successfully, we have to wait for it
            // to complete before we can shut down the restore session safely
            if (didRestore) {
                observer.waitForCompletion();
            }

            // once the restore has finished, close down the session and we're done
            mRestore.endRestoreSession();
        } catch (RemoteException e) {
            System.err.println(e.toString());
            System.err.println(BMGR_NOT_RUNNING_ERR);
        }
    }

    private String nextArg() {
        if (mNextArg >= mArgs.length) {
            return null;
        }
        String arg = mArgs[mNextArg];
        mNextArg++;
        return arg;
    }

    private static void showUsage() {
        System.err.println("usage: bmgr [backup|restore|list|transport|run]");
        System.err.println("       bmgr backup PACKAGE");
        System.err.println("       bmgr enable BOOL");
        System.err.println("       bmgr enabled");
        System.err.println("       bmgr list transports");
        System.err.println("       bmgr list sets");
        System.err.println("       bmgr transport WHICH");
        System.err.println("       bmgr restore TOKEN");
        System.err.println("       bmgr restore PACKAGE");
        System.err.println("       bmgr run");
        System.err.println("       bmgr wipe PACKAGE");
        System.err.println("");
        System.err.println("The 'backup' command schedules a backup pass for the named package.");
        System.err.println("Note that the backup pass will effectively be a no-op if the package");
        System.err.println("does not actually have changed data to store.");
        System.err.println("");
        System.err.println("The 'enable' command enables or disables the entire backup mechanism.");
        System.err.println("If the argument is 'true' it will be enabled, otherwise it will be");
        System.err.println("disabled.  When disabled, neither backup or restore operations will");
        System.err.println("be performed.");
        System.err.println("");
        System.err.println("The 'enabled' command reports the current enabled/disabled state of");
        System.err.println("the backup mechanism.");
        System.err.println("");
        System.err.println("The 'list transports' command reports the names of the backup transports");
        System.err.println("currently available on the device.  These names can be passed as arguments");
        System.err.println("to the 'transport' command.  The currently selected transport is indicated");
        System.err.println("with a '*' character.");
        System.err.println("");
        System.err.println("The 'list sets' command reports the token and name of each restore set");
        System.err.println("available to the device via the current transport.");
        System.err.println("");
        System.err.println("The 'transport' command designates the named transport as the currently");
        System.err.println("active one.  This setting is persistent across reboots.");
        System.err.println("");
        System.err.println("The 'restore' command when given a restore token initiates a full-system");
        System.err.println("restore operation from the currently active transport.  It will deliver");
        System.err.println("the restore set designated by the TOKEN argument to each application");
        System.err.println("that had contributed data to that restore set.");
        System.err.println("");
        System.err.println("The 'restore' command when given a package name intiates a restore of");
        System.err.println("just that one package according to the restore set selection algorithm");
        System.err.println("used by the RestoreSession.restorePackage() method.");
        System.err.println("");
        System.err.println("The 'run' command causes any scheduled backup operation to be initiated");
        System.err.println("immediately, without the usual waiting period for batching together");
        System.err.println("data changes.");
        System.err.println("");
        System.err.println("The 'wipe' command causes all backed-up data for the given package to be");
        System.err.println("erased from the current transport's storage.  The next backup operation");
        System.err.println("that the given application performs will rewrite its entire data set.");
    }
}