content: /*
   * Copyright (C) 2008 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.util;
  
  import java.io.DataInputStream;
  import java.io.DataOutputStream;
  import java.io.IOException;
  
  /**
   * Utility methods for Backup/Restore
   * @hide
   */
  public class BackupUtils {
  
      public static final int NULL = 0;
      public static final int NOT_NULL = 1;
  
      /**
       * Thrown when there is a backup version mismatch
       * between the data received and what the system can handle
       */
      public static class BadVersionException extends Exception {
          public BadVersionException(String message) {
              super(message);
          }
      }
  
      public static String readString(DataInputStream in) throws IOException {
          return (in.readByte() == NOT_NULL) ? in.readUTF() : null;
      }
  
      public static void writeString(DataOutputStream out, String val) throws IOException {
          if (val != null) {
              out.writeByte(NOT_NULL);
              out.writeUTF(val);
          } else {
              out.writeByte(NULL);
          }
      }
  }