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
17package android.util;
18
19import java.io.DataInputStream;
20import java.io.DataOutputStream;
21import java.io.IOException;
22
23/**
24 * Utility methods for Backup/Restore
25 * @hide
26 */
27public 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}