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 <a href="http://mina.apache.org">Apache MINA Project</a>
35 */
36 public class PrefixedStringCodecFactory implements ProtocolCodecFactory {
37
38 private final PrefixedStringEncoder encoder;
39
40 private final PrefixedStringDecoder decoder;
41
42 /**
43 * Creates a new PrefixedStringCodecFactory instance
44 *
45 * @param charset The {@link Charset} to use for encoding or decoding
46 */
47 public PrefixedStringCodecFactory(Charset charset) {
48 encoder = new PrefixedStringEncoder(charset);
49 decoder = new PrefixedStringDecoder(charset);
50 }
51
52 /**
53 * Creates a new PrefixedStringCodecFactory instance
54 */
55 public PrefixedStringCodecFactory() {
56 this(Charset.defaultCharset());
57 }
58
59 /**
60 * Returns the allowed maximum size of an encoded string.
61 * If the size of the encoded String exceeds this value, the encoder
62 * will throw a {@link IllegalArgumentException}.
63 * The default value is {@link PrefixedStringEncoder#DEFAULT_MAX_DATA_LENGTH}.
64 * <p>
65 * This method does the same job as {@link PrefixedStringEncoder#setMaxDataLength(int)}.
66 *
67 * @return the allowed maximum size of an encoded string.
68 */
69 public int getEncoderMaxDataLength() {
70 return encoder.getMaxDataLength();
71 }
72
73 /**
74 * Sets the allowed maximum size of an encoded String.
75 * If the size of the encoded String exceeds this value, the encoder
76 * will throw a {@link IllegalArgumentException}.
77 * The default value is {@link PrefixedStringEncoder#DEFAULT_MAX_DATA_LENGTH}.
78 * <p>
79 * This method does the same job as {@link PrefixedStringEncoder#getMaxDataLength()}.
80 *
81 * @param maxDataLength allowed maximum size of an encoded String.
82 */
83 public void setEncoderMaxDataLength(int maxDataLength) {
84 encoder.setMaxDataLength(maxDataLength);
85 }
86
87 /**
88 * @return the allowed maximum size of a decoded string.
89 * <p>
90 * This method does the same job as {@link PrefixedStringEncoder#setMaxDataLength(int)}.
91 * @see #setDecoderMaxDataLength(int)
92 */
93 public int getDecoderMaxDataLength() {
94 return decoder.getMaxDataLength();
95 }
96
97 /**
98 * Sets the maximum allowed value specified as data length in the decoded data
99 * <p>
100 * Useful for preventing an OutOfMemory attack by the peer.
101 * The decoder will throw a {@link BufferDataException} when data length
102 * specified in the incoming data is greater than maxDataLength
103 * The default value is {@link PrefixedStringDecoder#DEFAULT_MAX_DATA_LENGTH}.
104 * <p>
105 * This method does the same job as {@link PrefixedStringDecoder#setMaxDataLength(int)}.
106 *
107 * @param maxDataLength maximum allowed value specified as data length in the incoming data
108 */
109 public void setDecoderMaxDataLength(int maxDataLength) {
110 decoder.setMaxDataLength(maxDataLength);
111 }
112
113 /**
114 * Sets the length of the prefix used by the decoder
115 *
116 * @param prefixLength the length of the length prefix (1, 2, or 4)
117 */
118 public void setDecoderPrefixLength(int prefixLength) {
119 decoder.setPrefixLength(prefixLength);
120 }
121
122 /**
123 * Gets the length of the length prefix (1, 2, or 4) used by the decoder
124 *
125 * @return length of the length prefix
126 */
127 public int getDecoderPrefixLength() {
128 return decoder.getPrefixLength();
129 }
130
131 /**
132 * Sets the length of the prefix used by the encoder
133 *
134 * @param prefixLength the length of the length prefix (1, 2, or 4)
135 */
136 public void setEncoderPrefixLength(int prefixLength) {
137 encoder.setPrefixLength(prefixLength);
138 }
139
140 /**
141 * Gets the length of the length prefix (1, 2, or 4) used by the encoder
142 *
143 * @return length of the length prefix
144 */
145 public int getEncoderPrefixLength() {
146 return encoder.getPrefixLength();
147 }
148
149 /**
150 * {@inheritDoc}
151 */
152 @Override
153 public ProtocolEncoder getEncoder(IoSession session) throws Exception {
154 return encoder;
155 }
156
157 /**
158 * {@inheritDoc}
159 */
160 @Override
161 public ProtocolDecoder getDecoder(IoSession session) throws Exception {
162 return decoder;
163 }
164 }