1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.util; 18 19 import java.io.DataInputStream; 20 import java.io.DataOutputStream; 21 import java.io.IOException; 22 23 /** 24 * Utility methods for Backup/Restore 25 * @hide 26 */ 27 public class BackupUtils { 28 29 public static final int NULL = 0; 30 public static final int NOT_NULL = 1; 31 32 /** 33 * Thrown when there is a backup version mismatch 34 * between the data received and what the system can handle 35 */ 36 public static class BadVersionException extends Exception { 37 public BadVersionException(String message) { 38 super(message); 39 } 40 } 41 42 public static String readString(DataInputStream in) throws IOException { 43 return (in.readByte() == NOT_NULL) ? in.readUTF() : null; 44 } 45 46 public static void writeString(DataOutputStream out, String val) throws IOException { 47 if (val != null) { 48 out.writeByte(NOT_NULL); 49 out.writeUTF(val); 50 } else { 51 out.writeByte(NULL); 52 } 53 } 54 }
