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.filter.codec.prefixedstring;
21
22 import org.apache.mina.core.buffer.BufferDataException;
23 import org.apache.mina.core.session.IoSession;
24 import org.apache.mina.filter.codec.ProtocolCodecFactory;
25 import org.apache.mina.filter.codec.ProtocolDecoder;
26 import org.apache.mina.filter.codec.ProtocolEncoder;
27
28 import java.nio.charset.Charset;
29
30 /**
31 * A {@link ProtocolCodecFactory} that performs encoding and decoding
32 * of a Java String object using a fixed-length length prefix.
33 *
34 * @author The Apache MINA Project (dev@mina.apache.org)
35 * @version $Rev: 596187 $, $Date: 2007-11-19 04:41:14 +0100 (ma, 19 nov 2007) $
36 */
37 public class PrefixedStringCodecFactory implements ProtocolCodecFactory {
38
39 private final PrefixedStringEncoder encoder;
40
41 private final PrefixedStringDecoder decoder;
42
43 public PrefixedStringCodecFactory(Charset charset) {
44 encoder = new PrefixedStringEncoder(charset);
45 decoder = new PrefixedStringDecoder(charset);
46 }
47
48 public PrefixedStringCodecFactory() {
49 this(Charset.defaultCharset());
50 }
51
52 /**
53 * Returns the allowed maximum size of an encoded string.
54 * If the size of the encoded String exceeds this value, the encoder
55 * will throw a {@link IllegalArgumentException}.
56 * The default value is {@link PrefixedStringEncoder#DEFAULT_MAX_DATA_LENGTH}.
57 * <p/>
58 * This method does the same job as {@link PrefixedStringEncoder#setMaxDataLength(int)}.
59 *
60 * @return the allowed maximum size of an encoded string.
61 */
62 public int getEncoderMaxDataLength() {
63 return encoder.getMaxDataLength();
64 }
65
66 /**
67 * Sets the allowed maximum size of an encoded String.
68 * If the size of the encoded String exceeds this value, the encoder
69 * will throw a {@link IllegalArgumentException}.
70 * The default value is {@link PrefixedStringEncoder#DEFAULT_MAX_DATA_LENGTH}.
71 * <p/>
72 * This method does the same job as {@link PrefixedStringEncoder#getMaxDataLength()}.
73 *
74 * @param maxDataLength allowed maximum size of an encoded String.
75 */
76 public void setEncoderMaxDataLength(int maxDataLength) {
77 encoder.setMaxDataLength(maxDataLength);
78 }
79
80 /**
81 * Returns the allowed maximum size of a decoded string.
82 * <p>
83 * This method does the same job as {@link PrefixedStringEncoder#setMaxDataLength(int)}.
84 * </p>
85 *
86 * @return the allowed maximum size of an encoded string.
87 * @see #setDecoderMaxDataLength(int)
88 */
89 public int getDecoderMaxDataLength() {
90 return decoder.getMaxDataLength();
91 }
92
93 /**
94 * Sets the maximum allowed value specified as data length in the decoded data
95 * <p>
96 * Useful for preventing an OutOfMemory attack by the peer.
97 * The decoder will throw a {@link BufferDataException} when data length
98 * specified in the incoming data is greater than maxDataLength
99 * The default value is {@link PrefixedStringDecoder#DEFAULT_MAX_DATA_LENGTH}.
100 *
101 * This method does the same job as {@link PrefixedStringDecoder#setMaxDataLength(int)}.
102 * </p>
103 *
104 * @param maxDataLength maximum allowed value specified as data length in the incoming data
105 */
106 public void setDecoderMaxDataLength(int maxDataLength) {
107 decoder.setMaxDataLength(maxDataLength);
108 }
109
110 /**
111 * Sets the length of the prefix used by the decoder
112 *
113 * @param prefixLength the length of the length prefix (1, 2, or 4)
114 */
115 public void setDecoderPrefixLength(int prefixLength) {
116 decoder.setPrefixLength(prefixLength);
117 }
118
119 /**
120 * Gets the length of the length prefix (1, 2, or 4) used by the decoder
121 *
122 * @return length of the length prefix
123 */
124 public int getDecoderPrefixLength() {
125 return decoder.getPrefixLength();
126 }
127
128 /**
129 * Sets the length of the prefix used by the encoder
130 *
131 * @param prefixLength the length of the length prefix (1, 2, or 4)
132 */
133 public void setEncoderPrefixLength(int prefixLength) {
134 encoder.setPrefixLength(prefixLength);
135 }
136
137 /**
138 * Gets the length of the length prefix (1, 2, or 4) used by the encoder
139 *
140 * @return length of the length prefix
141 */
142 public int getEncoderPrefixLength() {
143 return encoder.getPrefixLength();
144 }
145
146 public ProtocolEncoder getEncoder(IoSession session) throws Exception {
147 return encoder;
148 }
149
150 public ProtocolDecoder getDecoder(IoSession session) throws Exception {
151 return decoder;
152 }
153 }