Save This Page
1 /*
2 * Copyright (c) 2002-2006 by OpenSymphony
3 * All rights reserved.
4 */
5 package com.opensymphony.xwork2;
6
7 import java.io.Serializable;
8 import java.util.HashMap;
9 import java.util.Map;
10
11 import com.opensymphony.xwork2.config.ConfigurationException;
12 import com.opensymphony.xwork2.config.entities.ActionConfig;
13 import com.opensymphony.xwork2.config.entities.InterceptorConfig;
14 import com.opensymphony.xwork2.config.entities.ResultConfig;
15 import com.opensymphony.xwork2.inject.Container;
16 import com.opensymphony.xwork2.inject.Inject;
17 import com.opensymphony.xwork2.interceptor.Interceptor;
18 import com.opensymphony.xwork2.util.ClassLoaderUtil;
19 import com.opensymphony.xwork2.util.logging.Logger;
20 import com.opensymphony.xwork2.util.logging.LoggerFactory;
21 import com.opensymphony.xwork2.util.reflection.ReflectionProvider;
22 import com.opensymphony.xwork2.validator.Validator;
23
24
25 /**
26 * ObjectFactory is responsible for building the core framework objects. Users may register their
27 * own implementation of the ObjectFactory to control instantiation of these Objects.
28 * <p/>
29 * This default implementation uses the {@link #buildBean(Class,java.util.Map) buildBean}
30 * method to create all classes (interceptors, actions, results, etc).
31 * <p/>
32 *
33 * @author Jason Carreira
34 */
35 public class ObjectFactory implements Serializable {
36 private static final Logger LOG = LoggerFactory.getLogger(ObjectFactory.class);
37
38 private transient ClassLoader ccl;
39 private Container container;
40 protected ReflectionProvider reflectionProvider;
41
42 @Inject(value="objectFactory.classloader", required=false)
43 public void setClassLoader(ClassLoader cl) {
44 this.ccl = cl;
45 }
46
47 @Inject
48 public void setReflectionProvider(ReflectionProvider prov) {
49 this.reflectionProvider = prov;
50 }
51
52 public ObjectFactory() {
53 }
54
55 public ObjectFactory(ReflectionProvider prov) {
56 this.reflectionProvider = prov;
57 }
58
59 @Inject
60 public void setContainer(Container container) {
61 this.container = container;
62 }
63
64 /**
65 * @deprecated Since 2.1
66 */
67 public static ObjectFactory getObjectFactory() {
68 return ActionContext.getContext().getContainer().getInstance(ObjectFactory.class);
69 }
70
71 /**
72 * Allows for ObjectFactory implementations that support
73 * Actions without no-arg constructors.
74 *
75 * @return true if no-arg constructor is required, false otherwise
76 */
77 public boolean isNoArgConstructorRequired() {
78 return true;
79 }
80
81 /**
82 * Utility method to obtain the class matched to className. Caches look ups so that subsequent
83 * lookups will be faster.
84 *
85 * @param className The fully qualified name of the class to return
86 * @return The class itself
87 * @throws ClassNotFoundException
88 */
89 public Class getClassInstance(String className) throws ClassNotFoundException {
90 if (ccl != null) {
91 return ccl.loadClass(className);
92 }
93
94 return ClassLoaderUtil.loadClass(className, this.getClass());
95 }
96
97 /**
98 * Build an instance of the action class to handle a particular request (eg. web request)
99 * @param actionName the name the action configuration is set up with in the configuration
100 * @param namespace the namespace the action is configured in
101 * @param config the action configuration found in the config for the actionName / namespace
102 * @param extraContext a Map of extra context which uses the same keys as the {@link com.opensymphony.xwork2.ActionContext}
103 * @return instance of the action class to handle a web request
104 * @throws Exception
105 */
106 public Object buildAction(String actionName, String namespace, ActionConfig config, Map extraContext) throws Exception {
107 return buildBean(config.getClassName(), extraContext);
108 }
109
110 /**
111 * Build a generic Java object of the given type.
112 *
113 * @param clazz the type of Object to build
114 * @param extraContext a Map of extra context which uses the same keys as the {@link com.opensymphony.xwork2.ActionContext}
115 */
116 public Object buildBean(Class clazz, Map extraContext) throws Exception {
117 return clazz.newInstance();
118 }
119
120 /**
121 * @param obj
122 */
123 protected Object injectInternalBeans(Object obj) {
124 if (obj != null && container != null) {
125 container.inject(obj);
126 }
127 return obj;
128 }
129
130 /**
131 * Build a generic Java object of the given type.
132 *
133 * @param className the type of Object to build
134 * @param extraContext a Map of extra context which uses the same keys as the {@link com.opensymphony.xwork2.ActionContext}
135 */
136 public Object buildBean(String className, Map extraContext) throws Exception {
137 return buildBean(className, extraContext, true);
138 }
139
140 /**
141 * Build a generic Java object of the given type.
142 *
143 * @param className the type of Object to build
144 * @param extraContext a Map of extra context which uses the same keys as the {@link com.opensymphony.xwork2.ActionContext}
145 */
146 public Object buildBean(String className, Map extraContext, boolean injectInternal) throws Exception {
147 Class clazz = getClassInstance(className);
148 Object obj = buildBean(clazz, extraContext);
149 if (injectInternal) {
150 injectInternalBeans(obj);
151 }
152 return obj;
153 }
154
155 /**
156 * Builds an Interceptor from the InterceptorConfig and the Map of
157 * parameters from the interceptor reference. Implementations of this method
158 * should ensure that the Interceptor is parameterized with both the
159 * parameters from the Interceptor config and the interceptor ref Map (the
160 * interceptor ref params take precedence), and that the Interceptor.init()
161 * method is called on the Interceptor instance before it is returned.
162 *
163 * @param interceptorConfig the InterceptorConfig from the configuration
164 * @param interceptorRefParams a Map of params provided in the Interceptor reference in the
165 * Action mapping or InterceptorStack definition
166 */
167 public Interceptor buildInterceptor(InterceptorConfig interceptorConfig, Map interceptorRefParams) throws ConfigurationException {
168 String interceptorClassName = interceptorConfig.getClassName();
169 Map thisInterceptorClassParams = interceptorConfig.getParams();
170 Map params = (thisInterceptorClassParams == null) ? new HashMap() : new HashMap(thisInterceptorClassParams);
171 params.putAll(interceptorRefParams);
172
173 String message;
174 Throwable cause;
175
176 try {
177 // interceptor instances are long-lived and used across user sessions, so don't try to pass in any extra context
178 Interceptor interceptor = (Interceptor) buildBean(interceptorClassName, null);
179 reflectionProvider.setProperties(params, interceptor);
180 interceptor.init();
181
182 return interceptor;
183 } catch (InstantiationException e) {
184 cause = e;
185 message = "Unable to instantiate an instance of Interceptor class [" + interceptorClassName + "].";
186 } catch (IllegalAccessException e) {
187 cause = e;
188 message = "IllegalAccessException while attempting to instantiate an instance of Interceptor class [" + interceptorClassName + "].";
189 } catch (ClassCastException e) {
190 cause = e;
191 message = "Class [" + interceptorClassName + "] does not implement com.opensymphony.xwork2.interceptor.Interceptor";
192 } catch (Exception e) {
193 cause = e;
194 message = "Caught Exception while registering Interceptor class " + interceptorClassName;
195 } catch (NoClassDefFoundError e) {
196 cause = e;
197 message = "Could not load class " + interceptorClassName + ". Perhaps it exists but certain dependencies are not available?";
198 }
199
200 throw new ConfigurationException(message, cause, interceptorConfig);
201 }
202
203 /**
204 * Build a Result using the type in the ResultConfig and set the parameters in the ResultConfig.
205 *
206 * @param resultConfig the ResultConfig found for the action with the result code returned
207 * @param extraContext a Map of extra context which uses the same keys as the {@link com.opensymphony.xwork2.ActionContext}
208 */
209 public Result buildResult(ResultConfig resultConfig, Map extraContext) throws Exception {
210 String resultClassName = resultConfig.getClassName();
211 Result result = null;
212
213 if (resultClassName != null) {
214 result = (Result) buildBean(resultClassName, extraContext);
215 reflectionProvider.setProperties(resultConfig.getParams(), result, extraContext, true);
216 }
217
218 return result;
219 }
220
221 /**
222 * Build a Validator of the given type and set the parameters on it
223 *
224 * @param className the type of Validator to build
225 * @param params property name -> value Map to set onto the Validator instance
226 * @param extraContext a Map of extra context which uses the same keys as the {@link com.opensymphony.xwork2.ActionContext}
227 */
228 public Validator buildValidator(String className, Map params, Map extraContext) throws Exception {
229 Validator validator = (Validator) buildBean(className, null);
230 reflectionProvider.setProperties(params, validator);
231
232 return validator;
233 }
234
235 static class ContinuationsClassLoader extends ClassLoader {
236
237 }
238 }