001 /*
002 * $Id: GroovyCategorySupport.java,v 1.6 2004/07/10 03:31:42 bran Exp $version Apr 26, 2004 4:22:50 PM $user Exp $
003 *
004 * Copyright 2003 (C) Sam Pullara. All Rights Reserved.
005 *
006 * Redistribution and use of this software and associated documentation
007 * ("Software"), with or without modification, are permitted provided that the
008 * following conditions are met: 1. Redistributions of source code must retain
009 * copyright statements and notices. Redistributions must also contain a copy
010 * of this document. 2. Redistributions in binary form must reproduce the above
011 * copyright notice, this list of conditions and the following disclaimer in
012 * the documentation and/or other materials provided with the distribution. 3.
013 * The name "groovy" must not be used to endorse or promote products derived
014 * from this Software without prior written permission of The Codehaus. For
015 * written permission, please contact info@codehaus.org. 4. Products derived
016 * from this Software may not be called "groovy" nor may "groovy" appear in
017 * their names without prior written permission of The Codehaus. "groovy" is a
018 * registered trademark of The Codehaus. 5. Due credit should be given to The
019 * Codehaus - http://groovy.codehaus.org/
020 *
021 * THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS ``AS IS'' AND ANY
022 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
023 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
024 * DISCLAIMED. IN NO EVENT SHALL THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR
025 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
026 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
027 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
028 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
029 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
030 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
031 * DAMAGE.
032 *
033 */
034 package org.codehaus.groovy.runtime;
035
036 import groovy.lang.Closure;
037 import groovy.lang.MetaMethod;
038
039 import java.lang.reflect.Method;
040 import java.lang.reflect.Modifier;
041 import java.util.ArrayList;
042 import java.util.Collections;
043 import java.util.HashMap;
044 import java.util.Iterator;
045 import java.util.List;
046 import java.util.Map;
047 import java.util.WeakHashMap;
048
049
050 /**
051 * @author sam
052 */
053 public class GroovyCategorySupport {
054
055 /**
056 * This method is used to pull all the new methods out of the local thread context with a particular name.
057 *
058 * @param categorizedClass
059 * @param name
060 * @return
061 */
062 public static List getCategoryMethods(Class categorizedClass, String name) {
063 Map properties = getProperties();
064 List methodList = new ArrayList();
065 for (Iterator i = properties.keySet().iterator(); i.hasNext(); ) {
066 Class current = (Class) i.next();
067 if (current.isAssignableFrom(categorizedClass)) {
068 Map metaMethodsMap = (Map) properties.get(current);
069 List newMethodList = (List) metaMethodsMap.get(name);
070 if (newMethodList != null) {
071 methodList.addAll(newMethodList);
072 }
073 }
074 }
075 if (methodList.size() == 0) return null;
076 return methodList;
077 }
078
079 /**
080 * This method is delegated to from the global use(CategoryClass) method. It scans the Category class for static methods
081 * that take 1 or more parameters. The first parameter is the class you are adding the category method to, additional parameters
082 * are those paramteres needed by that method. A use statement cannot be undone and is valid only for the current thread.
083 *
084 * @param categoryClass
085 */
086 private static void use(Class categoryClass) {
087 Map properties = getProperties();
088 Method[] methods = categoryClass.getMethods();
089 for (int i = 0; i < methods.length; i++) {
090 Method method = methods[i];
091 if (Modifier.isStatic(method.getModifiers())) {
092 Class[] paramTypes = method.getParameterTypes();
093 if (paramTypes.length > 0) {
094 Class metaClass = paramTypes[0];
095 Map metaMethodsMap = getMetaMethods(properties, metaClass);
096 List methodList = getMethodList(metaMethodsMap, method.getName());
097 MetaMethod mmethod = new NewInstanceMetaMethod(new MetaMethod(method)) {
098 public boolean isCacheable() { return false; }
099 };
100 methodList.add(mmethod);
101 }
102 }
103 }
104 }
105
106 /**
107 * @param clazz
108 * @param closure
109 */
110 public static void use(Class clazz, Closure closure) {
111 newScope();
112 try {
113 use(clazz);
114 closure.call();
115 } finally {
116 endScope();
117 }
118 }
119
120 /**
121 * @param classes
122 * @param closure
123 */
124 public static void use(List classes, Closure closure) {
125 newScope();
126 try {
127 for (Iterator i = classes.iterator(); i.hasNext(); ) {
128 Class clazz = (Class) i.next();
129 use(clazz);
130 }
131 closure.call();
132 } finally {
133 endScope();
134 }
135 }
136
137 private static ThreadLocal local = new ThreadLocal() {
138 protected Object initialValue() {
139 List stack = new ArrayList();
140 stack.add(Collections.EMPTY_MAP);
141 return stack;
142 }
143 };
144
145 private static void newScope() {
146 List stack = (List) local.get();
147 Map properties = new WeakHashMap(getProperties());
148 stack.add(properties);
149 }
150
151 private static void endScope() {
152 List stack = (List) local.get();
153 stack.remove(stack.size() - 1);
154 }
155
156 private static Map getProperties() {
157 List stack = (List) local.get();
158 Map properties = (Map) stack.get(stack.size() - 1);
159 return properties;
160 }
161
162 /**
163 * @param method
164 * @param metaMethodsMap
165 * @return
166 */
167 private static List getMethodList(Map metaMethodsMap, String name) {
168 List methodList = (List) metaMethodsMap.get(name);
169 if (methodList == null) {
170 methodList = new ArrayList(1);
171 metaMethodsMap.put(name, methodList);
172 }
173 return methodList;
174 }
175
176 /**
177 * @param properties
178 * @param metaClass
179 * @return
180 */
181 private static Map getMetaMethods(Map properties, Class metaClass) {
182 Map metaMethodsMap = (Map) properties.get(metaClass);
183 if (metaMethodsMap == null) {
184 metaMethodsMap = new HashMap();
185 properties.put(metaClass, metaMethodsMap);
186 }
187 return metaMethodsMap;
188 }
189
190 }