| /* |
| * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//dbcp/src/java/org/apache/commons/jocl/ConstructorUtil.java,v 1.1 2001/04/14 17:16:12 rwaldhoff Exp $ |
| * $Revision: 1.1 $ |
| * $Date: 2001/04/14 17:16:12 $ |
| * |
| * ==================================================================== |
| * |
| * The Apache Software License, Version 1.1 |
| * |
| * Copyright (c) 1999-2001 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", "Commons", 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 |
| * <http://www.apache.org/>. |
| * |
| */ |
| |
| package org.apache.commons.jocl; |
| |
| import java.lang.reflect.Constructor; |
| import java.lang.reflect.InvocationTargetException; |
| |
| /** |
| * Miscellaneous {@link Constructor} related utility functions. |
| * |
| * @version $Id: ConstructorUtil.java,v 1.1 2001/04/14 17:16:12 rwaldhoff Exp $ |
| * @author Rodney Waldhoff |
| */ |
| public class ConstructorUtil { |
| /** |
| * Returns a {@link Constructor} for the given method signature, or <tt>null</tt> |
| * if no such <tt>Constructor</tt> can be found. |
| * |
| * @param type the (non-<tt>null</tt>) type of {@link Object} the returned {@link Constructor} should create |
| * @param argTypes a non-<tt>null</tt> array of types describing the parameters to the {@link Constructor}. |
| * @return a {@link Constructor} for the given method signature, or <tt>null</tt> |
| * if no such <tt>Constructor</tt> can be found. |
| * @see #invokeConstructor |
| */ |
| public static Constructor getConstructor(Class type, Class[] argTypes) { |
| if(null == type || null == argTypes) { |
| throw new NullPointerException(); |
| } |
| Constructor ctor = null; |
| try { |
| ctor = type.getConstructor(argTypes); |
| } catch(Exception e) { |
| ctor = null; |
| } |
| if(null == ctor) { |
| // no directly declared matching constructor, |
| // look for something that will work |
| // XXX this should really be more careful to |
| // adhere to the jls mechanism for late binding |
| Constructor[] ctors = type.getConstructors(); |
| for(int i=0;i<ctors.length;i++) { |
| Class[] paramtypes = ctors[i].getParameterTypes(); |
| if(paramtypes.length == argTypes.length) { |
| boolean canuse = true; |
| for(int j=0;j<paramtypes.length;j++) { |
| if(paramtypes[j].isAssignableFrom(argTypes[j])) { |
| continue; |
| } else { |
| canuse = false; |
| break; |
| } |
| } |
| if(canuse = true) { |
| ctor = ctors[i]; |
| break; |
| } |
| } |
| } |
| } |
| return ctor; |
| } |
| |
| /** |
| * Creates a new instance of the specified <tt><i>type</i></tt> |
| * using a {@link Constructor} described by the given parameter types |
| * and values. |
| * |
| * @param type the type of {@link Object} to be created |
| * @param argTypes a non-<tt>null</tt> array of types describing the parameters to the {@link Constructor}. |
| * @param argValues a non-<tt>null</tt> array containing the values of the parameters to the {@link Constructor}. |
| * @return a new instance of the specified <tt><i>type</i></tt> |
| * using a {@link Constructor} described by the given parameter types |
| * and values. |
| * @exception InstantiationException |
| * @exception IllegalAccessException |
| * @exception InvocationTargetException |
| */ |
| public static Object invokeConstructor(Class type, Class[] argTypes, Object[] argValues) throws InstantiationException, IllegalAccessException, InvocationTargetException { |
| return ConstructorUtil.getConstructor(type,argTypes).newInstance(argValues); |
| } |
| } |
| |
| |
