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 */
36 public class PrefixedStringCodecFactory implements ProtocolCodecFactory {
37
38 private final PrefixedStringEncoder encoder;
39
40 private final PrefixedStringDecoder decoder;
41
42 public PrefixedStringCodecFactory(Charset charset) {
43 encoder = new PrefixedStringEncoder(charset);
44 decoder = new PrefixedStringDecoder(charset);
45 }
46
47 public PrefixedStringCodecFactory() {
48 this(Charset.defaultCharset());
49 }
50
51 /**
52 * Returns the allowed maximum size of an encoded string.
53 * If the size of the encoded String exceeds this value, the encoder
54 * will throw a {@link IllegalArgumentException}.
55 * The default value is {@link PrefixedStringEncoder#DEFAULT_MAX_DATA_LENGTH}.
56 * <p/>
57 * This method does the same job as {@link PrefixedStringEncoder#setMaxDataLength(int)}.
58 *
59 * @return the allowed maximum size of an encoded string.
60 */
61 public int getEncoderMaxDataLength() {
62 return encoder.getMaxDataLength();
63 }
64
65 /**
66 * Sets the allowed maximum size of an encoded String.
67 * If the size of the encoded String exceeds this value, the encoder
68 * will throw a {@link IllegalArgumentException}.
69 * The default value is {@link PrefixedStringEncoder#DEFAULT_MAX_DATA_LENGTH}.
70 * <p/>
71 * This method does the same job as {@link PrefixedStringEncoder#getMaxDataLength()}.
72 *
73 * @param maxDataLength allowed maximum size of an encoded String.
74 */
75 public void setEncoderMaxDataLength(int maxDataLength) {
76 encoder.setMaxDataLength(maxDataLength);
77 }
78
79 /**
80 * Returns the allowed maximum size of a decoded string.
81 * <p>
82 * This method does the same job as {@link PrefixedStringEncoder#setMaxDataLength(int)}.
83 * </p>
84 *
85 * @return the allowed maximum size of an encoded string.
86 * @see #setDecoderMaxDataLength(int)
87 */
88 public int getDecoderMaxDataLength() {
89 return decoder.getMaxDataLength();
90 }
91
92 /**
93 * Sets the maximum allowed value specified as data length in the decoded data
94 * <p>
95 * Useful for preventing an OutOfMemory attack by the peer.
96 * The decoder will throw a {@link BufferDataException} when data length
97 * specified in the incoming data is greater than maxDataLength
98 * The default value is {@link PrefixedStringDecoder#DEFAULT_MAX_DATA_LENGTH}.
99 *
100 * This method does the same job as {@link PrefixedStringDecoder#setMaxDataLength(int)}.
101 * </p>
102 *
103 * @param maxDataLength maximum allowed value specified as data length in the incoming data
104 */
105 public void setDecoderMaxDataLength(int maxDataLength) {
106 decoder.setMaxDataLength(maxDataLength);
107 }
108
109 /**
110 * Sets the length of the prefix used by the decoder
111 *
112 * @param prefixLength the length of the length prefix (1, 2, or 4)
113 */
114 public void setDecoderPrefixLength(int prefixLength) {
115 decoder.setPrefixLength(prefixLength);
116 }
117
118 /**
119 * Gets the length of the length prefix (1, 2, or 4) used by the decoder
120 *
121 * @return length of the length prefix
122 */
123 public int getDecoderPrefixLength() {
124 return decoder.getPrefixLength();
125 }
126
127 /**
128 * Sets the length of the prefix used by the encoder
129 *
130 * @param prefixLength the length of the length prefix (1, 2, or 4)
131 */
132 public void setEncoderPrefixLength(int prefixLength) {
133 encoder.setPrefixLength(prefixLength);
134 }
135
136 /**
137 * Gets the length of the length prefix (1, 2, or 4) used by the encoder
138 *
139 * @return length of the length prefix
140 */
141 public int getEncoderPrefixLength() {
142 return encoder.getPrefixLength();
143 }
144
145 public ProtocolEncoder getEncoder(IoSession session) throws Exception {
146 return encoder;
147 }
148
149 public ProtocolDecoder getDecoder(IoSession session) throws Exception {
150 return decoder;
151 }
152 }