1 /**
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18
19 package org.apache.hadoop.hbase.io;
20
21 import java.io.DataInput;
22 import java.io.IOException;
23 import java.io.InputStream;
24
25 import org.apache.hadoop.classification.InterfaceAudience;
26
27 /**
28 * An InputStream that wraps a DataInput.
29 * @see DataOutputOutputStream
30 */
31 @InterfaceAudience.Private
32 public class DataInputInputStream extends InputStream {
33
34 private DataInput in;
35
36 /**
37 * Construct an InputStream from the given DataInput. If 'in'
38 * is already an InputStream, simply returns it. Otherwise, wraps
39 * it in an InputStream.
40 * @param in the DataInput to wrap
41 * @return an InputStream instance that reads from 'in'
42 */
43 public static InputStream constructInputStream(DataInput in) {
44 if (in instanceof InputStream) {
45 return (InputStream)in;
46 } else {
47 return new DataInputInputStream(in);
48 }
49 }
50
51
52 public DataInputInputStream(DataInput in) {
53 this.in = in;
54 }
55
56 @Override
57 public int read() throws IOException {
58 return in.readUnsignedByte();
59 }
60 }