Android example source code file (BackupTestActivity.java)

This example Android source code file (BackupTestActivity.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, backuphelperdispatcher, bufferedreader, file, helpers, io, ioexception, mode_private, os, override, pref_key, printstream, runtimeexception, show, string, stringbuffer, test, ui

The BackupTestActivity.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.backuptest;

import android.app.ListActivity;
import android.app.backup.BackupHelperDispatcher;
import android.app.backup.BackupDataInput;
import android.app.backup.BackupDataOutput;
import android.app.backup.BackupManager;
import android.app.backup.FileBackupHelper;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.os.Handler;
import android.os.ParcelFileDescriptor;
import android.util.Log;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStreamReader;
import java.io.IOException;
import java.io.PrintStream;
import java.text.DateFormat;
import java.util.Date;

public class BackupTestActivity extends ListActivity
{
    static final String TAG = "BackupTestActivity";

    static final String PREF_GROUP_SETTINGS = "settings";
    static final String PREF_KEY = "pref";
    static final String FILE_NAME = "file.txt";

    BackupManager sBm = new BackupManager(this);

    Test[] mTests = new Test[] {
        new Test("Show File") {
            void run() {
                StringBuffer str = new StringBuffer();
                str.append("Text is:");
                BufferedReader reader = null;
                try {
                    reader = new BufferedReader(new InputStreamReader(openFileInput(FILE_NAME)));
                    while (reader.ready()) {
                        str.append("\n");
                        str.append(reader.readLine());
                    }
                } catch (IOException ex) {
                    str.append("ERROR: ");
                    str.append(ex.toString());
                }
                Log.d(TAG, str.toString());
                Toast.makeText(BackupTestActivity.this, str, Toast.LENGTH_SHORT).show();
            }
        },
        new Test("Append to File") {
            void run() {
                PrintStream output = null;
                try {
                    output = new PrintStream(openFileOutput(FILE_NAME, MODE_APPEND));
                    DateFormat formatter = DateFormat.getDateTimeInstance();
                    output.println(formatter.format(new Date()));
                    output.close();
                } catch (IOException ex) {
                    if (output != null) {
                        output.close();
                    }
                }
                sBm.dataChanged();
            }
        },
        new Test("Clear File") {
            void run() {
                PrintStream output = null;
                try {
                    output = new PrintStream(openFileOutput(FILE_NAME, MODE_PRIVATE));
                    output.close();
                } catch (IOException ex) {
                    if (output != null) {
                        output.close();
                    }
                }
                sBm.dataChanged();
            }
        },
        new Test("Poke") {
            void run() {
                sBm.dataChanged();
            }
        },
        new Test("Show Shared Pref") {
            void run() {
                SharedPreferences prefs = getSharedPreferences(PREF_GROUP_SETTINGS, MODE_PRIVATE);
                int val = prefs.getInt(PREF_KEY, 0);
                String str = "'" + PREF_KEY + "' is " + val;
                Log.d(TAG, str);
                Toast.makeText(BackupTestActivity.this, str, Toast.LENGTH_SHORT).show();
            }
        },
        new Test("Increment Shared Pref") {
            void run() {
                SharedPreferences prefs = getSharedPreferences(PREF_GROUP_SETTINGS, MODE_PRIVATE);
                int val = prefs.getInt(PREF_KEY, 0);
                SharedPreferences.Editor editor = prefs.edit();
                editor.putInt(PREF_KEY, val+1);
                editor.commit();
                sBm.dataChanged();
            }
        },
        new Test("Backup Helpers") {
            void run() {
                try {
                    writeFile("a", "a\naa", MODE_PRIVATE);
                    writeFile("empty", "", MODE_PRIVATE);

                    ParcelFileDescriptor state = ParcelFileDescriptor.open(
                            new File(getFilesDir(), "state"),
                            ParcelFileDescriptor.MODE_READ_WRITE|ParcelFileDescriptor.MODE_CREATE|
                            ParcelFileDescriptor.MODE_TRUNCATE);
                    FileBackupHelper h = new FileBackupHelper(BackupTestActivity.this,
                            new String[] { "a", "empty" });
                    FileOutputStream dataFile = openFileOutput("backup_test", MODE_WORLD_READABLE);
                    BackupDataOutput data = new BackupDataOutput(dataFile.getFD());
                    h.performBackup(null, data, state);
                    dataFile.close();
                    state.close();
                } catch (IOException ex) {
                    throw new RuntimeException(ex);
                }
            }
        },
        new Test("Restore Helpers") {
            void run() {
                try {
                    BackupHelperDispatcher dispatch = new BackupHelperDispatcher();
                    dispatch.addHelper("", new FileBackupHelper(BackupTestActivity.this,
                            new String[] { "a", "empty" }));
                    FileInputStream dataFile = openFileInput("backup_test");
                    BackupDataInput data = new BackupDataInput(dataFile.getFD());
                    ParcelFileDescriptor state = ParcelFileDescriptor.open(
                            new File(getFilesDir(), "restore_state"),
                            ParcelFileDescriptor.MODE_READ_WRITE|ParcelFileDescriptor.MODE_CREATE|
                            ParcelFileDescriptor.MODE_TRUNCATE);
                    // TODO: a more plausable synthetic stored-data version number
                    dispatch.performRestore(data, 0, state);
                    dataFile.close();
                    state.close();
                } catch (IOException ex) {
                    throw new RuntimeException(ex);
                }
            }
        }
    };

    abstract class Test {
        String name;
        Test(String n) {
            name = n;
        }
        abstract void run();
    }

    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);

        String[] labels = new String[mTests.length];
        for (int i=0; i<mTests.length; i++) {
            labels[i] = mTests[i].name;
        }

        setListAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, labels));
    }

    @Override
    public void onListItemClick(ListView l, View v, int position, long id)
    {
        Test t = mTests[position];
        Log.d(TAG, "Test: " + t.name);
        t.run();
    }
    
    void writeFile(String name, String contents, int mode) {
        try {
            PrintStream out = new PrintStream(openFileOutput(name, mode));
            out.print(contents);
            out.close();
        } catch (FileNotFoundException ex) {
            throw new RuntimeException(ex);
        }
    }
}