1 package org.apache.commons.jcs.utils.serialization;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import org.apache.commons.jcs.engine.behavior.IElementSerializer;
23 import org.apache.commons.jcs.io.ObjectInputStreamClassLoaderAware;
24 import org.apache.commons.jcs.utils.zip.CompressionUtil;
25
26 import java.io.BufferedInputStream;
27 import java.io.ByteArrayInputStream;
28 import java.io.ByteArrayOutputStream;
29 import java.io.IOException;
30 import java.io.ObjectInputStream;
31 import java.io.ObjectOutputStream;
32
33 /**
34 * Performs default serialization and de-serialization. It gzips the value.
35 */
36 public class CompressingSerializer
37 implements IElementSerializer
38 {
39 /**
40 * Serializes an object using default serialization. Compresses the byte array.
41 * <p>
42 * @param obj object
43 * @return byte[]
44 * @throws IOException on i/o problem
45 */
46 @Override
47 public <T> byte[] serialize( T obj )
48 throws IOException
49 {
50 byte[] uncompressed = serializeObject( obj );
51 byte[] compressed = CompressionUtil.compressByteArray( uncompressed );
52 return compressed;
53 }
54
55 /**
56 * Does the basic serialization.
57 * <p>
58 * @param obj object
59 * @return byte[]
60 * @throws IOException on i/o problem
61 */
62 protected <T> byte[] serializeObject( T obj )
63 throws IOException
64 {
65 ByteArrayOutputStream baos = new ByteArrayOutputStream();
66 ObjectOutputStream oos = new ObjectOutputStream( baos );
67 try
68 {
69 oos.writeObject( obj );
70 }
71 finally
72 {
73 oos.close();
74 }
75 byte[] uncompressed = baos.toByteArray();
76 return uncompressed;
77 }
78
79 /**
80 * Uses default de-serialization to turn a byte array into an object. Decompresses the value
81 * first. All exceptions are converted into IOExceptions.
82 * <p>
83 * @param data bytes of data
84 * @return Object
85 * @throws IOException on i/o problem
86 * @throws ClassNotFoundException if class is not found during deserialization
87 */
88 @Override
89 public <T> T deSerialize( byte[] data, ClassLoader loader )
90 throws IOException, ClassNotFoundException
91 {
92 if ( data == null )
93 {
94 return null;
95 }
96 byte[] decompressedByteArray = CompressionUtil.decompressByteArray( data );
97 return deserializeObject( decompressedByteArray );
98 }
99
100 /**
101 * Does the standard deserialization.
102 * <p>
103 * @param decompressedByteArray array of decompressed bytes
104 * @return Object
105 * @throws IOException on i/o error
106 * @throws ClassNotFoundException if class is not found during deserialization
107 */
108 protected <T> T deserializeObject( byte[] decompressedByteArray )
109 throws IOException, ClassNotFoundException
110 {
111 ByteArrayInputStream bais = new ByteArrayInputStream( decompressedByteArray );
112 BufferedInputStream bis = new BufferedInputStream( bais );
113 ObjectInputStream ois = new ObjectInputStreamClassLoaderAware( bis, null );
114
115 try
116 {
117 @SuppressWarnings("unchecked") // Need to cast from Object
118 T readObject = (T) ois.readObject();
119 return readObject;
120 }
121 finally
122 {
123 ois.close();
124 }
125 }
126 }