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1 package org.jbpm.instantiation;
2
3 import java.io.*;
4 import java.util.*;
5
6 import org.apache.commons.logging.*;
7 import org.dom4j.*;
8 import org.dom4j.Node;
9 import org.dom4j.io.*;
10 import org.jbpm.graph.def.*;
11 import org.jbpm.jpdl.xml.*;
12
13 public class Delegation implements Parsable, Serializable {
14
15 private static final long serialVersionUID = 1L;
16
17 protected static Map instantiatorCache = new HashMap();
18 static {
19 instantiatorCache.put(null, new FieldInstantiator());
20 instantiatorCache.put("field", new FieldInstantiator());
21 instantiatorCache.put("bean", new BeanInstantiator());
22 instantiatorCache.put("constructor", new ConstructorInstantiator());
23 instantiatorCache.put("configuration-property", new ConfigurationPropertyInstantiator());
24 }
25
26 long id = 0;
27 protected String  className = null;
28 protected String configuration = null;
29 protected String configType = null;
30 protected ProcessDefinition processDefinition = null;
31 private transient Object instance = null;
32
33 public Delegation() {
34 }
35
36 public Delegation(Object instance) {
37 this.instance = instance;
38 }
39
40 public Delegation(String className) {
41 this.className = className;
42 }
43
44 public void read(Element delegateElement, JpdlXmlReader jpdlReader) {
45 processDefinition = jpdlReader.getProcessDefinition();
46 className = delegateElement.attributeValue("class");
47 if (className==null) {
48 jpdlReader.addWarning("no class specified in "+delegateElement.asXML());
49 }
50
51 configType = delegateElement.attributeValue("config-type");
52 if ( delegateElement.hasContent() ) {
53 try {
54 StringWriter stringWriter = new StringWriter();
55 XMLWriter xmlWriter = new XMLWriter( stringWriter, OutputFormat.createCompactFormat() );
57 Iterator iter = delegateElement.content().iterator();
58 while (iter.hasNext()) {
59 xmlWriter.write( iter.next() );
60 }
61 xmlWriter.flush();
62 configuration = stringWriter.toString();
63 } catch (IOException e) {
64 jpdlReader.addWarning("io problem while parsing the configuration of "+delegateElement.asXML());
65 }
66 }
67 }
68
69 public void write(Element element) {
70 element.addAttribute("class", className);
71 element.addAttribute("config-type", configType);
72 String configuration = this.configuration;
73 if (configuration!=null) {
74 try {
75 Element actionElement = DocumentHelper.parseText( "<action>"+configuration+"</action>" ).getRootElement();
76 Iterator iter = new ArrayList( actionElement.content() ).iterator();
77 while (iter.hasNext()) {
78 Node node = (Node)iter.next();
79 node.setParent(null);
80 element.add( node );
81 }
82 } catch (DocumentException e) {
83 log.error("couldn't create dom-tree for action configuration '"+configuration+"'", e);
84 }
85 }
86 }
87
88 public Object getInstance() {
89 if (instance==null) {
90 instance = instantiate();
91 }
92 return instance;
93 }
94
95 public Object instantiate() {
96
97 Object newInstance = null;
98
99 ClassLoader classLoader = ClassLoaderUtil.getProcessClassLoader(processDefinition);
101
102 Class clazz = null;
104 try {
105 clazz = classLoader.loadClass(className);
106 } catch (ClassNotFoundException e) {
107 log.error("couldn't load delegation class '"+className+"'", e);
108 }
109
110 Instantiator instantiator = null;
111 try {
112 instantiator = (Instantiator) instantiatorCache.get(configType);
114 if (instantiator == null) {
115 Class instantiatorClass = classLoader.loadClass(configType);
117 instantiator = (Instantiator) instantiatorClass.newInstance();
119 instantiatorCache.put(configType, instantiator);
120 }
121 } catch (Exception e) {
122 log.error(e);
123 throw new RuntimeException ("couldn't instantiate custom instantiator '" + configType + "'", e);
124 }
125
126 try {
127 newInstance = instantiator.instantiate(clazz, configuration);
129 } catch (RuntimeException e) {
130 log.error("couldn't instantiate delegation class '"+className+"'", e);
131 }
132
133 return newInstance;
134 }
135
136 public String getClassName() {
137 return className;
138 }
139
140 public void setClassName(String className) {
141 this.className = className;
142 }
143
144 public String getConfiguration() {
145 return configuration;
146 }
147
148 public void setConfiguration(String configuration) {
149 this.configuration = configuration;
150 }
151
152 public String getConfigType() {
153 return configType;
154 }
155
156 public void setConfigType(String instantiatorType) {
157 this.configType = instantiatorType;
158 }
159
160 public long getId() {
161 return id;
162 }
163
164 public void setId(long id) {
165 this.id = id;
166 }
167
168 public ProcessDefinition getProcessDefinition() {
169 return processDefinition;
170 }
171 public void setProcessDefinition(ProcessDefinition processDefinition) {
172 this.processDefinition = processDefinition;
173 }
174
175 private static final Log log = LogFactory.getLog(Delegation.class);
176
177 }
178 |
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