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1   /*
2    * Copyright (c) 2007, James Leigh All rights reserved.
3    * 
4    * Redistribution and use in source and binary forms, with or without
5    * modification, are permitted provided that the following conditions are met:
6    * 
7    * - Redistributions of source code must retain the above copyright notice, this
8    *   list of conditions and the following disclaimer.
9    * - Redistributions in binary form must reproduce the above copyright notice,
10   *   this list of conditions and the following disclaimer in the documentation
11   *   and/or other materials provided with the distribution. 
12   * - Neither the name of the openrdf.org nor the names of its contributors may
13   *   be used to endorse or promote products derived from this software without
14   *   specific prior written permission.
15   * 
16   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
20   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26   * POSSIBILITY OF SUCH DAMAGE.
27   * 
28   */
29  package org.openrdf.elmo.sesame.converters.impl;
30  
31  import java.io.ByteArrayInputStream;
32  import java.io.ByteArrayOutputStream;
33  import java.io.InputStream;
34  import java.io.ObjectInputStream;
35  import java.io.ObjectOutputStream;
36  
37  import org.openrdf.elmo.exceptions.ElmoConversionException;
38  import org.openrdf.elmo.sesame.converters.Marshall;
39  import org.openrdf.model.Literal;
40  import org.openrdf.model.URI;
41  import org.openrdf.model.ValueFactory;
42  
43  public class ObjectSerializationMarshall<T> implements Marshall<T> {
44  	private static final String pseudo[] = { "0", "1", "2", "3", "4", "5", "6", "7", "8",
45  			"9", "A", "B", "C", "D", "E", "F" };
46  	private ValueFactory vf;
47  
48  	private Class<T> type;
49  
50  	private URI datatype;
51  
52  	public ObjectSerializationMarshall(ValueFactory vf, Class<T> type) {
53  		super();
54  		this.vf = vf;
55  		this.type = type;
56  		this.datatype = vf.createURI("java:", type.getName());
57  	}
58  
59  	public Class<T> getJavaClass() {
60  		return type;
61  	}
62  
63  	public URI getDatatype() {
64  		return datatype;
65  	}
66  
67  	public void setDatatype(URI datatype) {
68  		this.datatype = datatype;
69  	}
70  
71  	public T deserialize(Literal literal) {
72  		try {
73  			byte[] decoded = decode(literal.getLabel());
74  			InputStream is = new ByteArrayInputStream(decoded);
75  			ObjectInputStream ois = new ObjectInputStream(is);
76  			Object result = ois.readObject();
77  			ois.close();
78  			return type.cast(result);
79  		} catch (ElmoConversionException e) {
80  			throw e;
81  		} catch (Exception e) {
82  			throw new ElmoConversionException(e);
83  		}
84  	}
85  
86  	public Literal serialize(T object) {
87  		try {
88  			ByteArrayOutputStream bos = new ByteArrayOutputStream();
89  			ObjectOutputStream oos = new ObjectOutputStream(bos);
90  			oos.writeObject(object);
91  			oos.close();
92  			byte[] byteArray = bos.toByteArray();
93  			String label = encode(byteArray);
94  			return vf.createLiteral(label, datatype);
95  		} catch (ElmoConversionException e) {
96  			throw e;
97  		} catch (Exception e) {
98  			throw new ElmoConversionException(e);
99  		}
100 	}
101 
102 	private String encode(byte[] in) {
103 		StringBuilder out = new StringBuilder(in.length * 2);
104 		for (int i = 0; i < in.length; i++) {
105 			byte ch = (byte) (in[i] & 0xF0);
106 			ch = (byte) (ch >>> 4);
107 			ch = (byte) (ch & 0x0F);
108 			out.append(pseudo[ch]);
109 			ch = (byte) (in[i] & 0x0F);
110 			out.append(pseudo[ch]);
111 		}
112 		return out.toString();
113 	}
114 
115 	private byte[] decode(String str) {
116 		char[] in = str.toCharArray();
117         byte[] out = new byte[in.length / 2];
118         if (in.length % 2 == 1)
119             throw new ElmoConversionException("Hex String must be an odd number of characters");
120         int j = 0;
121         for (int i = 0; i < out.length; i++) {
122             int most = Character.digit(in[j++], 16);
123             int least = Character.digit(in[j++], 16);
124 			int value = most << 4 | least;
125             out[i] = (byte) (value & 0xFF);
126         }
127         return out;
128 	}
129 }