/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.frameworkset.commons.jocl;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
/**
* Miscellaneous {@link Constructor} related utility functions.
*
* @author Rodney Waldhoff
* @version $Revision: 479137 $ $Date: 2006-11-25 10:51:48 -0500 (Sat, 25 Nov 2006) $
*/
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);
}
}