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1   /*
2    * Copyright 2006-2013 the original author or authors.
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  
17  package org.springframework.batch.core.repository.dao;
18  
19  import java.io.BufferedReader;
20  import java.io.IOException;
21  import java.io.InputStream;
22  import java.io.InputStreamReader;
23  import java.io.OutputStream;
24  
25  import org.springframework.batch.core.repository.ExecutionContextSerializer;
26  import org.springframework.beans.factory.InitializingBean;
27  import org.springframework.core.serializer.Deserializer;
28  import org.springframework.core.serializer.Serializer;
29  import org.springframework.util.Assert;
30  
31  import com.thoughtworks.xstream.XStream;
32  import com.thoughtworks.xstream.converters.reflection.ReflectionProvider;
33  import com.thoughtworks.xstream.io.HierarchicalStreamDriver;
34  import com.thoughtworks.xstream.io.json.JettisonMappedXmlDriver;
35  
36  /**
37   * Implementation that uses XStream and Jettison to provide serialization.
38   *
39   * @author Thomas Risberg
40   * @author Michael Minella
41   * @since 2.0
42   * @see ExecutionContextSerializer
43   */
44  public class XStreamExecutionContextStringSerializer implements ExecutionContextSerializer, InitializingBean {
45  
46  	private ReflectionProvider reflectionProvider = null;
47  
48  	private HierarchicalStreamDriver hierarchicalStreamDriver;
49  
50  	private XStream xstream;
51  
52  	public void setReflectionProvider(ReflectionProvider reflectionProvider) {
53  		this.reflectionProvider = reflectionProvider;
54  	}
55  
56  	public void setHierarchicalStreamDriver(HierarchicalStreamDriver hierarchicalStreamDriver) {
57  		this.hierarchicalStreamDriver = hierarchicalStreamDriver;
58  	}
59  
60  	@Override
61  	public void afterPropertiesSet() throws Exception {
62  		init();
63  	}
64  
65  	public synchronized void init() throws Exception {
66  		if (hierarchicalStreamDriver == null) {
67  			this.hierarchicalStreamDriver = new JettisonMappedXmlDriver();
68  		}
69  		if (reflectionProvider == null) {
70  			xstream =  new XStream(hierarchicalStreamDriver);
71  		}
72  		else {
73  			xstream = new XStream(reflectionProvider, hierarchicalStreamDriver);
74  		}
75  	}
76  
77  	/**
78  	 * Serializes the passed execution context to the supplied OutputStream.
79  	 *
80  	 * @param context
81  	 * @param out
82  	 * @see Serializer#serialize(Object, OutputStream)
83  	 */
84  	@Override
85  	public void serialize(Object context, OutputStream out) throws IOException {
86  		Assert.notNull(context);
87  		Assert.notNull(out);
88  
89  		out.write(xstream.toXML(context).getBytes());
90  	}
91  
92  	/**
93  	 * Deserializes the supplied input stream into a new execution context.
94  	 *
95  	 * @param in
96  	 * @return a reconstructed execution context
97  	 * @see Deserializer#deserialize(InputStream)
98  	 */
99  	@Override
100 	public Object deserialize(InputStream in) throws IOException {
101 		BufferedReader br = new BufferedReader(new InputStreamReader(in));
102 
103 		StringBuilder sb = new StringBuilder();
104 
105 		String line;
106 		while ((line = br.readLine()) != null) {
107 			sb.append(line);
108 		}
109 
110 		return xstream.fromXML(sb.toString());
111 	}
112 }