Return-Path: Delivered-To: apmail-jakarta-velocity-dev-archive@jakarta.apache.org Received: (qmail 11416 invoked by uid 500); 11 Sep 2001 17:18:12 -0000 Mailing-List: contact velocity-dev-help@jakarta.apache.org; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Reply-To: velocity-dev@jakarta.apache.org Delivered-To: mailing list velocity-dev@jakarta.apache.org Received: (qmail 11407 invoked by uid 500); 11 Sep 2001 17:18:12 -0000 Delivered-To: apmail-jakarta-velocity-cvs@apache.org Date: 11 Sep 2001 17:14:03 -0000 Message-ID: <20010911171403.58975.qmail@icarus.apache.org> From: dlr@apache.org To: jakarta-velocity-cvs@apache.org Subject: cvs commit: jakarta-velocity/src/java/org/apache/velocity/util/introspection Introspector.java X-Spam-Rating: daedalus.apache.org 1.6.2 0/1000/N dlr 01/09/11 10:14:03 Modified: src/java/org/apache/velocity/util/introspection Introspector.java Log: JavaDoc improvements. Revision Changes Path 1.12 +207 -1 jakarta-velocity/src/java/org/apache/velocity/util/introspection/Introspector.java Index: Introspector.java =================================================================== RCS file: /home/cvs/jakarta-velocity/src/java/org/apache/velocity/util/introspection/Introspector.java,v retrieving revision 1.11 retrieving revision 1.12 diff -u -u -r1.11 -r1.12 --- Introspector.java 2001/09/10 10:36:09 1.11 +++ Introspector.java 2001/09/11 17:14:03 1.12 @@ -1 +1,207 @@ -package org.apache.velocity.util.introspection; /* * The Apache Software License, Version 1.1 * * Copyright (c) 2001 The Apache Software Foundation. All rights * reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. The end-user documentation included with the redistribution, if * any, must include the following acknowlegement: * "This product includes software developed by the * Apache Software Foundation (http://www.apache.org/)." * Alternately, this acknowlegement may appear in the software itself, * if and wherever such third-party acknowlegements normally appear. * * 4. The names "The Jakarta Project", "Velocity", and "Apache Software * Foundation" must not be used to endorse or promote products derived * from this software without prior written permission. For written * permission, please contact apache@apache.org. * * 5. Products derived from this software may not be called "Apache" * nor may "Apache" appear in their names without prior written * permission of the Apache Group. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * . */ import java.util.*; import java.lang.reflect.Method; import java.lang.reflect.Modifier; import org.apache.velocity.runtime.RuntimeServices; /** * This basic function of this class is to return a Method * object for a particular class given the name of a method * and the parameters to the method in the form of an Object[] * * The first time the Introspector sees a * class it creates a class method map for the * class in question. Basically the class method map * is a Hastable where Method objects are keyed by a * concatenation of the method name and the names of * classes that make up the parameters. * * For example, a method with the following signature: * * public void method(String a, StringBuffer b) * * would be mapped by the key: * * "method" + "java.lang.String" + "java.lang.StringBuffer" * * This mapping is performed for all the methods in a class * and stored for * @author Jason van Zyl * @author Bob McWhirter * @author Attila Szegedi * @author Paulo Gaspar * @version $Id: Introspector.java,v 1.11 2001/09/10 10:36:09 geirm Exp $ */ public class Introspector { private RuntimeServices rsvc = null; /* * Holds the method maps for the classes we know about, * keyed by Class */ private final Map classMethodMaps = new HashMap(); /* * Holds the qualified class name to Class mapping */ private final Map classByName = new HashMap(); /** * Recieves our RuntimeServices object */ public void init( RuntimeServices r ) { this.rsvc = r; } public Method getMethod(Class c, String name, Object[] params) throws Exception { if (c == null) { throw new Exception ( "Introspector.getMethod(): Class method key was null: " + name ); } ClassMap classMap = null; synchronized(classMethodMaps) { classMap = (ClassMap)classMethodMaps.get(c); /* * if we don't have this, check to see if we have it * by name. if so, then we have a classloader change * so dump our caches. */ if ( classMap == null) { Class cachedClass = (Class) classByName.get( c.getName() ); if ( cachedClass != null) { clearCache(); rsvc.info("Introspector : detected classloader change. Dumping cache."); } classMap = createClassMap(c); } } return classMap.findMethod(name, params); } /** * Creates a class map for specific class and registers it in the * cache. Also adds the qualified name to the name->class map * for later Classloader change detection. */ private ClassMap createClassMap(Class c) { ClassMap classMap = new ClassMap(c); classMethodMaps.put( c, classMap); classByName.put(c.getName(), c); return classMap; } /** * Clears the classmap and classname * caches */ private void clearCache() { classMethodMaps.clear(); classByName.clear(); } /** * Checks whether the provided object implements a given method. * * * @param object The object to check. * @param methodName The method to check for. * @return Whether the method is implemented. */ public boolean implementsMethod(Object object, String methodName) { int m; Method[] methods = object.getClass().getMethods(); for (m = 0 ; m < methods.length ; ++m) { if (methodName.equals(methods[m].getName())) { break; } } return (m < methods.length); } } \ No newline at end of file +package org.apache.velocity.util.introspection; + +/* + * The Apache Software License, Version 1.1 + * + * Copyright (c) 2001 The Apache Software Foundation. All rights + * reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * 3. The end-user documentation included with the redistribution, if + * any, must include the following acknowlegement: + * "This product includes software developed by the + * Apache Software Foundation (http://www.apache.org/)." + * Alternately, this acknowlegement may appear in the software itself, + * if and wherever such third-party acknowlegements normally appear. + * + * 4. The names "The Jakarta Project", "Velocity", and "Apache Software + * Foundation" must not be used to endorse or promote products derived + * from this software without prior written permission. For written + * permission, please contact apache@apache.org. + * + * 5. Products derived from this software may not be called "Apache" + * nor may "Apache" appear in their names without prior written + * permission of the Apache Group. + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR + * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * ==================================================================== + * + * This software consists of voluntary contributions made by many + * individuals on behalf of the Apache Software Foundation. For more + * information on the Apache Software Foundation, please see + * . + */ + +import java.util.*; + +import java.lang.reflect.Method; +import java.lang.reflect.Modifier; + +import org.apache.velocity.runtime.RuntimeServices; + +/** + * This basic function of this class is to return a Method + * object for a particular class given the name of a method + * and the parameters to the method in the form of an Object[] + * + * The first time the Introspector sees a + * class it creates a class method map for the + * class in question. Basically the class method map + * is a Hastable where Method objects are keyed by a + * concatenation of the method name and the names of + * classes that make up the parameters. + * + * For example, a method with the following signature: + * + * public void method(String a, StringBuffer b) + * + * would be mapped by the key: + * + * "method" + "java.lang.String" + "java.lang.StringBuffer" + * + * This mapping is performed for all the methods in a class + * and stored for + * @author Jason van Zyl + * @author Bob McWhirter + * @author Attila Szegedi + * @author Paulo Gaspar + * @version $Id: Introspector.java,v 1.12 2001/09/11 17:14:03 dlr Exp $ + */ +public class Introspector +{ + private RuntimeServices rsvc = null; + + /** + * Holds the method maps for the classes we know about, keyed by + * Class object. + */ + private final Map classMethodMaps = new HashMap(); + + /** + * Holds the qualified class name to Class object mapping. + */ + private final Map classByName = new HashMap(); + + /** + * Recieves our RuntimeServices object + */ + public void init( RuntimeServices r ) + { + this.rsvc = r; + } + + /** + * Gets the method defined by name and + * params for the Class c. + * + * @return The desired Method object. + */ + public Method getMethod(Class c, String name, Object[] params) + throws Exception + { + if (c == null) + { + throw new Exception ( + "Introspector.getMethod(): Class method key was null: " + name ); + } + + ClassMap classMap = null; + + synchronized(classMethodMaps) + { + classMap = (ClassMap)classMethodMaps.get(c); + + /* + * if we don't have this, check to see if we have it + * by name. if so, then we have a classloader change + * so dump our caches. + */ + + if (classMap == null) + { + Class cachedClass = (Class) classByName.get( c.getName() ); + + if (cachedClass != null) + { + clearCache(); + rsvc.info("Introspector : detected classloader change. Dumping cache."); + } + + classMap = createClassMap(c); + } + } + + return classMap.findMethod(name, params); + } + + /** + * Creates a class map for specific class and registers it in the + * cache. Also adds the qualified name to the name->class map + * for later Classloader change detection. + */ + private ClassMap createClassMap(Class c) + { + ClassMap classMap = new ClassMap(c); + classMethodMaps.put(c, classMap); + classByName.put(c.getName(), c); + + return classMap; + } + + /** + * Clears the classmap and classname + * caches + */ + private void clearCache() + { + classMethodMaps.clear(); + classByName.clear(); + } + + /** + * Checks whether the provided object implements a given method. + * + * + * @param object The object to check. + * @param methodName The method to check for. + * @return Whether the method is implemented. + */ + public boolean implementsMethod(Object object, String methodName) + { + int m; + + Method[] methods = object.getClass().getMethods(); + + for (m = 0 ; m < methods.length ; ++m) + { + if (methodName.equals(methods[m].getName())) + { + break; + } + } + + return (m < methods.length); + } +}