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,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 *
19 */
20 package org.apache.mina.util;
21
22 import java.io.OutputStream;
23 import java.nio.ByteBuffer;
24
25 /**
26 * {@link OutputStream} wrapper for {@link ByteBuffer}
27 *
28 * <p>
29 * <i>Currently this class is only used and available in MINA's codec module</i>
30 * </p>
31 *
32 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
33 *
34 */
35 public class ByteBufferOutputStream extends OutputStream {
36 private ByteBuffer buffer;
37
38 private boolean elastic = false;
39
40 public ByteBufferOutputStream() {
41 this(1024);
42 }
43
44 private ByteBufferOutputStream(ByteBuffer buffer) {
45 this.buffer = buffer;
46 }
47
48 public ByteBufferOutputStream(int initialSize) {
49 this(ByteBuffer.allocate(initialSize));
50 }
51
52 public ByteBuffer getByteBuffer() {
53 ByteBuffer out = buffer.asReadOnlyBuffer();
54 out.limit(out.position());
55 out.position(0);
56
57 return out;
58 }
59
60 public boolean isElastic() {
61 return elastic;
62 }
63
64 private void needSpace(int len) {
65 if (elastic && buffer.capacity() - buffer.position() < len) {
66 ByteBuffer newBuffer = ByteBuffer.allocate(Math.max(buffer.capacity() * 2, buffer.position() + len));
67 buffer.limit(buffer.position());
68 newBuffer.put(buffer);
69 buffer = newBuffer;
70 }
71 }
72
73 public void setElastic(boolean elastic) {
74 this.elastic = elastic;
75 }
76
77 @Override
78 public void write(byte[] b, int off, int len) {
79 needSpace(len);
80 buffer.put(b, off, len);
81 }
82
83 @Override
84 public void write(int b) {
85 needSpace(1);
86 buffer.put((byte) b);
87 }
88 }