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1 /*
2 * $Id: MethodBindingMethodExpressionAdapter.java,v 1.7 2007/04/27 22:00:12 ofung Exp $
3 */
4
5 /*
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
7 *
8 * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
9 *
10 * The contents of this file are subject to the terms of either the GNU
11 * General Public License Version 2 only ("GPL") or the Common Development
12 * and Distribution License("CDDL") (collectively, the "License"). You
13 * may not use this file except in compliance with the License. You can obtain
14 * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
15 * or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific
16 * language governing permissions and limitations under the License.
17 *
18 * When distributing the software, include this License Header Notice in each
19 * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
20 * Sun designates this particular file as subject to the "Classpath" exception
21 * as provided by Sun in the GPL Version 2 section of the License file that
22 * accompanied this code. If applicable, add the following below the License
23 * Header, with the fields enclosed by brackets [] replaced by your own
24 * identifying information: "Portions Copyrighted [year]
25 * [name of copyright owner]"
26 *
27 * Contributor(s):
28 *
29 * If you wish your version of this file to be governed by only the CDDL or
30 * only the GPL Version 2, indicate your decision by adding "[Contributor]
31 * elects to include this software in this distribution under the [CDDL or GPL
32 * Version 2] license." If you don't indicate a single choice of license, a
33 * recipient has the option to distribute your version of this file under
34 * either the CDDL, the GPL Version 2 or to extend the choice of license to
35 * its licensees as provided above. However, if you add GPL Version 2 code
36 * and therefore, elected the GPL Version 2 license, then the option applies
37 * only if the new code is made subject to such option by the copyright
38 * holder.
39 */
40
41 package javax.faces.component;
42
43 import java.io.Serializable;
44
45 import javax.faces.component.StateHolder;
46 import javax.faces.context.FacesContext;
47 import javax.faces.el.EvaluationException;
48 import javax.faces.el.ReferenceSyntaxException;
49 import javax.faces.el.MethodBinding;
50
51 import javax.el.MethodExpression;
52 import javax.el.MethodInfo;
53 import javax.el.ELException;
54 import javax.el.ELContext;
55 import javax.el.ExpressionFactory;
56 import javax.el.ValueExpression;
57
58 import java.util.Arrays;
59 import java.lang.reflect.Method;
60
61 /**
62 * <p>Wrap a MethodExpression instance and expose it as a MethodBinding</p>
63 *
64 */
65 class MethodBindingMethodExpressionAdapter extends MethodBinding implements StateHolder,
66 Serializable {
67
68 private static final long serialVersionUID = 7334926223014401689L;
69
70 private MethodExpression methodExpression= null;
71 private boolean tranzient;
72
73 public MethodBindingMethodExpressionAdapter() {} // for StateHolder
74
75 MethodBindingMethodExpressionAdapter(MethodExpression methodExpression) {
76 this.methodExpression = methodExpression;
77 }
78
79 public Object invoke(FacesContext context, Object params[])
80 throws javax.faces.el.EvaluationException, javax.faces.el.MethodNotFoundException {
81 assert(null != methodExpression);
82 if ( context == null ) {
83 throw new NullPointerException("FacesConext -> null");
84 }
85
86 Object result = null;
87 try {
88 result = methodExpression.invoke(context.getELContext(),
89 params);
90 }
91 catch (javax.el.MethodNotFoundException e) {
92 throw new javax.faces.el.MethodNotFoundException(e);
93 }
94 catch (javax.el.PropertyNotFoundException e) {
95 throw new EvaluationException(e);
96 }
97 catch (ELException e) {
98 Throwable cause = e.getCause();
99 if (cause == null) {
100 cause = e;
101 }
102 throw new EvaluationException(cause);
103 } catch (NullPointerException e) {
104 throw new javax.faces.el.MethodNotFoundException(e);
105 }
106 return result;
107 }
108
109 public Class getType(FacesContext context) throws javax.faces.el.MethodNotFoundException {
110 assert(null != methodExpression);
111 if (context == null) {
112 throw new NullPointerException("FacesConext -> null");
113 }
114 Class result = null;
115 if ( context == null ) {
116 throw new NullPointerException();
117 }
118
119 try {
120 MethodInfo mi =
121 methodExpression.getMethodInfo(context.getELContext());
122 result = mi.getReturnType();
123 }
124 catch (javax.el.PropertyNotFoundException e) {
125 throw new javax.faces.el.MethodNotFoundException(e);
126 }
127 catch (javax.el.MethodNotFoundException e) {
128 throw new javax.faces.el.MethodNotFoundException(e);
129 }
130 catch (ELException e) {
131 throw new javax.faces.el.MethodNotFoundException(e);
132 }
133 return result;
134 }
135
136
137 public String getExpressionString() {
138 assert(null != methodExpression);
139 return methodExpression.getExpressionString();
140 }
141
142 public boolean equals(Object other) {
143 if (this == other) {
144 return true;
145 }
146 if (other instanceof MethodBindingMethodExpressionAdapter) {
147 return methodExpression.equals(((MethodBindingMethodExpressionAdapter) other).getWrapped());
148 } else if (other instanceof MethodBinding) {
149 MethodBinding binding = (MethodBinding) other;
150
151 // We'll need to do a little leg work to determine
152 // if the MethodBinding is equivalent to the
153 // wrapped MethodExpression
154 String expr = binding.getExpressionString();
155 int idx = expr.indexOf('.');
156 String target = expr.substring(0, idx).substring(2);
157 String t = expr.substring(idx + 1);
158 String method = t.substring(0, (t.length() - 1));
159
160 FacesContext context = FacesContext.getCurrentInstance();
161 ELContext elContext = context.getELContext();
162 MethodInfo controlInfo = methodExpression.getMethodInfo(elContext);
163
164 // ensure the method names are the same
165 if (!controlInfo.getName().equals(method)) {
166 return false;
167 }
168
169 // Using the target, create an expression and evaluate
170 // it.
171 ExpressionFactory factory = context.getApplication().getExpressionFactory();
172 ValueExpression ve = factory.createValueExpression(elContext,
173 "#{" + target + '}',
174 Object.class);
175 if (ve == null) {
176 return false;
177 }
178
179 Object result = ve.getValue(elContext);
180
181 if (result == null) {
182 return false;
183 }
184
185 // Get all of the methods with the matching name and try
186 // to find a match based on controlInfo's return and parameter
187 // types
188 Class type = binding.getType(context);
189 Method[] methods = result.getClass().getMethods();
190 for (Method meth : methods) {
191 if (meth.getName().equals(method)
192 && type.equals(controlInfo.getReturnType())
193 && Arrays.equals(meth.getParameterTypes(),
194 controlInfo.getParamTypes())) {
195 return true;
196 }
197 }
198 }
199
200 return false;
201
202 }
203
204 public int hashCode() {
205 assert(null != methodExpression);
206
207 return methodExpression.hashCode();
208 }
209
210
211 public boolean isTransient() {
212 return this.tranzient;
213 }
214
215 public void setTransient(boolean tranzient) {
216 this.tranzient = tranzient;
217 }
218
219 public Object saveState(FacesContext context){
220 Object result = null;
221 if (!tranzient) {
222 if (methodExpression instanceof StateHolder) {
223 Object [] stateStruct = new Object[2];
224
225 // save the actual state of our wrapped methodExpression
226 stateStruct[0] = ((StateHolder)methodExpression).saveState(context);
227 // save the class name of the methodExpression impl
228 stateStruct[1] = methodExpression.getClass().getName();
229
230 result = stateStruct;
231 }
232 else {
233 result = methodExpression;
234 }
235 }
236
237 return result;
238
239 }
240
241 public void restoreState(FacesContext context, Object state) {
242 // if we have state
243 if (null == state) {
244 return;
245 }
246
247 if (!(state instanceof MethodExpression)) {
248 Object [] stateStruct = (Object []) state;
249 Object savedState = stateStruct[0];
250 String className = stateStruct[1].toString();
251 MethodExpression result = null;
252
253 Class toRestoreClass = null;
254 if (null != className) {
255 try {
256 toRestoreClass = loadClass(className, this);
257 }
258 catch (ClassNotFoundException e) {
259 throw new IllegalStateException(e.getMessage());
260 }
261
262 if (null != toRestoreClass) {
263 try {
264 result =
265 (MethodExpression) toRestoreClass.newInstance();
266 }
267 catch (InstantiationException e) {
268 throw new IllegalStateException(e.getMessage());
269 }
270 catch (IllegalAccessException a) {
271 throw new IllegalStateException(a.getMessage());
272 }
273 }
274
275 if (null != result && null != savedState) {
276 // don't need to check transient, since that was
277 // done on the saving side.
278 ((StateHolder)result).restoreState(context, savedState);
279 }
280 methodExpression = result;
281 }
282 }
283 else {
284 methodExpression = (MethodExpression) state;
285 }
286 }
287
288 public MethodExpression getWrapped() {
289 return methodExpression;
290 }
291
292 //
293 // Helper methods for StateHolder
294 //
295
296 private static Class loadClass(String name,
297 Object fallbackClass) throws ClassNotFoundException {
298 ClassLoader loader =
299 Thread.currentThread().getContextClassLoader();
300 if (loader == null) {
301 loader = fallbackClass.getClass().getClassLoader();
302 }
303 return Class.forName(name, true, loader);
304 }
305
306
307
308 }