001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.io;
019
020import java.io.DataOutput;
021import java.io.IOException;
022import java.io.OutputStream;
023
024import org.apache.hadoop.classification.InterfaceAudience;
025import org.apache.hadoop.classification.InterfaceStability;
026
027/**
028 * OutputStream implementation that wraps a DataOutput.
029 */
030@InterfaceAudience.Public
031@InterfaceStability.Unstable
032public class DataOutputOutputStream extends OutputStream {
033
034  private final DataOutput out;
035
036  /**
037   * Construct an OutputStream from the given DataOutput. If 'out'
038   * is already an OutputStream, simply returns it. Otherwise, wraps
039   * it in an OutputStream.
040   * @param out the DataOutput to wrap
041   * @return an OutputStream instance that outputs to 'out'
042   */
043  public static OutputStream constructOutputStream(DataOutput out) {
044    if (out instanceof OutputStream) {
045      return (OutputStream)out;
046    } else {
047      return new DataOutputOutputStream(out);
048    }
049  }
050  
051  private DataOutputOutputStream(DataOutput out) {
052    this.out = out;
053  }
054  
055  @Override
056  public void write(int b) throws IOException {
057    out.writeByte(b);
058  }
059
060  @Override
061  public void write(byte[] b, int off, int len) throws IOException {
062    out.write(b, off, len);
063  }
064
065  @Override
066  public void write(byte[] b) throws IOException {
067    out.write(b);
068  }
069  
070
071}