001    /*
002     * $Id: MetaMethod.java,v 1.18 2005/10/17 08:36:21 tug Exp $
003     *
004     * Copyright 2003 (C) James Strachan and Bob Mcwhirter. 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:
009     *  1. Redistributions of source code must retain copyright statements and
010     * notices. Redistributions must also contain a copy of this document.
011     *  2. Redistributions in binary form must reproduce the above copyright
012     * notice, this list of conditions and the following disclaimer in the
013     * documentation and/or other materials provided with the distribution.
014     *  3. The name "groovy" must not be used to endorse or promote products
015     * derived from this Software without prior written permission of The Codehaus.
016     * For written permission, please contact info@codehaus.org.
017     *  4. Products derived from this Software may not be called "groovy" nor may
018     * "groovy" appear in their names without prior written permission of The
019     * Codehaus. "groovy" is a registered trademark of The Codehaus.
020     *  5. Due credit should be given to The Codehaus - http://groovy.codehaus.org/
021     *
022     * THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS ``AS IS'' AND ANY
023     * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
024     * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
025     * DISCLAIMED. IN NO EVENT SHALL THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR
026     * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
027     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
028     * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
029     * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
030     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
031     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
032     * DAMAGE.
033     *
034     */
035    package groovy.lang;
036    
037    import java.lang.reflect.Method;
038    import java.lang.reflect.Modifier;
039    import java.security.AccessController;
040    import java.security.PrivilegedAction;
041    import java.util.logging.Logger;
042    
043    import org.codehaus.groovy.runtime.InvokerHelper;
044    import org.codehaus.groovy.runtime.MetaClassHelper;
045    import org.codehaus.groovy.runtime.Reflector;
046    
047    /**
048     * Represents a Method on a Java object a little like {@link java.lang.reflect.Method}
049     * except without using reflection to invoke the method
050     * 
051     * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
052     * @version $Revision: 1.18 $
053     */
054    public class MetaMethod implements Cloneable {
055    
056        private static final Logger log = Logger.getLogger(MetaMethod.class.getName());
057    
058        private String name;
059        private Class declaringClass;
060        private Class interfaceClass;
061        private Class[] parameterTypes;
062        private Class returnType;
063        private int modifiers;
064        private Reflector reflector;
065        private int methodIndex;
066        private Method method;
067    
068        public MetaMethod(String name, Class declaringClass, Class[] parameterTypes, Class returnType, int modifiers) {
069            this.name = name;
070            this.declaringClass = declaringClass;
071            this.parameterTypes = parameterTypes;
072            this.returnType = returnType;
073            this.modifiers = modifiers;
074        }
075    
076        public MetaMethod(Method method) {
077            this(
078                method.getName(),
079                method.getDeclaringClass(),
080                method.getParameterTypes(),
081                method.getReturnType(),
082                method.getModifiers());
083            this.method = method;
084        }
085    
086        public MetaMethod(MetaMethod metaMethod) {
087            this(metaMethod.method);
088        }
089    
090        /**
091         * Checks that the given parameters are valid to call this method
092         * 
093         * @param arguments
094         * @throws IllegalArgumentException if the parameters are not valid
095         */
096        public void checkParameters(Class[] arguments) {
097            // lets check that the argument types are valid
098            if (!MetaClassHelper.isValidMethod(getParameterTypes(), arguments, false)) {
099                throw new IllegalArgumentException(
100                        "Parameters to method: "
101                        + getName()
102                        + " do not match types: "
103                        + InvokerHelper.toString(getParameterTypes())
104                        + " for arguments: "
105                        + InvokerHelper.toString(arguments));
106            }
107        }
108        
109        public Object invoke(Object object, Object[] arguments) throws Exception {
110            if (reflector != null) {
111                return reflector.invoke(this, object, arguments);
112            }
113            else {
114                AccessController.doPrivileged(new PrivilegedAction() {
115                                    public Object run() {
116                                        method.setAccessible(true);
117                                        return null;
118                                    }
119                            });
120                return method.invoke(object, arguments);
121            }
122        }
123    
124        public Class getDeclaringClass() {
125            return declaringClass;
126        }
127        
128        public void setDeclaringClass(Class c) {
129            declaringClass=c;
130        }
131    
132        public int getMethodIndex() {
133            return methodIndex;
134        }
135    
136        public void setMethodIndex(int methodIndex) {
137            this.methodIndex = methodIndex;
138        }
139    
140        public int getModifiers() {
141            return modifiers;
142        }
143    
144        public String getName() {
145            return name;
146        }
147    
148        public Class[] getParameterTypes() {
149            return parameterTypes;
150        }
151    
152        public Class getReturnType() {
153            return returnType;
154        }
155    
156        public Reflector getReflector() {
157            return reflector;
158        }
159    
160        public void setReflector(Reflector reflector) {
161            this.reflector = reflector;
162        }
163    
164        public boolean isMethod(Method method) {
165            return name.equals(method.getName())
166                && modifiers == method.getModifiers()
167                && returnType.equals(method.getReturnType())
168                && equal(parameterTypes, method.getParameterTypes());
169        }
170    
171        protected boolean equal(Class[] a, Class[] b) {
172            if (a.length == b.length) {
173                for (int i = 0, size = a.length; i < size; i++) {
174                    if (!a[i].equals(b[i])) {
175                        return false;
176                    }
177                }
178                return true;
179            }
180            return false;
181        }
182    
183        public String toString() {
184            return super.toString()
185                + "[name: "
186                + name
187                + " params: "
188                + InvokerHelper.toString(parameterTypes)
189                + " returns: "
190                + returnType
191                + " owner: "
192                + declaringClass
193                + "]";
194        }
195    
196        public Object clone() {
197            try {
198                return super.clone();
199            }
200            catch (CloneNotSupportedException e) {
201                throw new GroovyRuntimeException("This should never happen", e);
202            }
203        }
204    
205        public boolean isStatic() {
206            return (modifiers & Modifier.STATIC) != 0;
207        }
208    
209        public boolean isPrivate() {
210            return (modifiers & Modifier.PRIVATE) != 0;
211        }
212    
213        public boolean isProtected() {
214            return (modifiers & Modifier.PROTECTED) != 0;
215        }
216    
217        public boolean isPublic() {
218            return (modifiers & Modifier.PUBLIC) != 0;
219        }
220    
221        /**
222         * @return true if the given method has the same name, parameters, return type
223         * and modifiers but may be defined on another type
224         */
225        public boolean isSame(MetaMethod method) {
226            return name.equals(method.getName())
227                && compatibleModifiers(modifiers, method.getModifiers())
228                && returnType.equals(method.getReturnType())
229                && equal(parameterTypes, method.getParameterTypes());
230        }
231    
232        protected boolean compatibleModifiers(int modifiersA, int modifiersB) {
233            int mask = Modifier.PRIVATE | Modifier.PROTECTED | Modifier.PUBLIC | Modifier.STATIC;
234            return (modifiersA & mask) == (modifiersB & mask);
235        }
236    
237        public Class getInterfaceClass() {
238            return interfaceClass;
239        }
240    
241        public void setInterfaceClass(Class interfaceClass) {
242            this.interfaceClass = interfaceClass;
243        }
244    
245        public boolean isCacheable() {
246            return true;
247        }
248    
249    }