1*ef39d40dSAndrew Rist /************************************************************** 2cdf0e10cSrcweir * 3*ef39d40dSAndrew Rist * Licensed to the Apache Software Foundation (ASF) under one 4*ef39d40dSAndrew Rist * or more contributor license agreements. See the NOTICE file 5*ef39d40dSAndrew Rist * distributed with this work for additional information 6*ef39d40dSAndrew Rist * regarding copyright ownership. The ASF licenses this file 7*ef39d40dSAndrew Rist * to you under the Apache License, Version 2.0 (the 8*ef39d40dSAndrew Rist * "License"); you may not use this file except in compliance 9*ef39d40dSAndrew Rist * with the License. You may obtain a copy of the License at 10*ef39d40dSAndrew Rist * 11*ef39d40dSAndrew Rist * http://www.apache.org/licenses/LICENSE-2.0 12*ef39d40dSAndrew Rist * 13*ef39d40dSAndrew Rist * Unless required by applicable law or agreed to in writing, 14*ef39d40dSAndrew Rist * software distributed under the License is distributed on an 15*ef39d40dSAndrew Rist * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16*ef39d40dSAndrew Rist * KIND, either express or implied. See the License for the 17*ef39d40dSAndrew Rist * specific language governing permissions and limitations 18*ef39d40dSAndrew Rist * under the License. 19*ef39d40dSAndrew Rist * 20*ef39d40dSAndrew Rist *************************************************************/ 21*ef39d40dSAndrew Rist 22*ef39d40dSAndrew Rist 23cdf0e10cSrcweir 24cdf0e10cSrcweir package util; 25cdf0e10cSrcweir 26cdf0e10cSrcweir import java.lang.reflect.Constructor; 27cdf0e10cSrcweir 28cdf0e10cSrcweir public class DynamicClassLoader { 29cdf0e10cSrcweir 30cdf0e10cSrcweir /** 31cdf0e10cSrcweir * This method returns a class created by its name 32cdf0e10cSrcweir * created by call to <code>Class.forName()</code>.<p> 33cdf0e10cSrcweir * This method must be overloaded if another loading 34cdf0e10cSrcweir * policy is required for Component and Interface 35cdf0e10cSrcweir * testing classes. 36cdf0e10cSrcweir * @param className The name of the class to create. 37cdf0e10cSrcweir * @return The created class. 38cdf0e10cSrcweir */ forName(String className)39cdf0e10cSrcweir public static Class forName(String className) 40cdf0e10cSrcweir throws ClassNotFoundException { 41cdf0e10cSrcweir 42cdf0e10cSrcweir return Class.forName(className) ; 43cdf0e10cSrcweir } 44cdf0e10cSrcweir 45cdf0e10cSrcweir /** 46cdf0e10cSrcweir * Get an instance of a class. The empty constructor is used. 47cdf0e10cSrcweir * @param className The class to instantiate. 48cdf0e10cSrcweir * @return The instance of the class. 49cdf0e10cSrcweir */ getInstance(String className)50cdf0e10cSrcweir public Object getInstance(String className) 51cdf0e10cSrcweir throws IllegalArgumentException { 52cdf0e10cSrcweir try { 53cdf0e10cSrcweir Class cls = DynamicClassLoader.forName(className); 54cdf0e10cSrcweir return cls.newInstance(); 55cdf0e10cSrcweir } catch ( ClassNotFoundException e ) { 56cdf0e10cSrcweir throw new IllegalArgumentException("Couldn't find " + className 57cdf0e10cSrcweir + " " + e); 58cdf0e10cSrcweir } catch ( IllegalAccessException e ) { 59cdf0e10cSrcweir throw new IllegalArgumentException("Couldn't access " + className 60cdf0e10cSrcweir + " " + e); 61cdf0e10cSrcweir } catch ( InstantiationException e ) { 62cdf0e10cSrcweir throw new IllegalArgumentException("Couldn't instantiate " + 63cdf0e10cSrcweir className + " " + e); 64cdf0e10cSrcweir } 65cdf0e10cSrcweir } 66cdf0e10cSrcweir 67cdf0e10cSrcweir /** 68cdf0e10cSrcweir * Get an instance of a class. The constructor matching to the 69cdf0e10cSrcweir * arguments is used and the arguments are given to this constructor. 70cdf0e10cSrcweir * @param className The class to instantiate. 71cdf0e10cSrcweir * @param ctorArgs Arguments for the constructor. 72cdf0e10cSrcweir * @return The instance of the class. 73cdf0e10cSrcweir */ getInstance(String className, Object[] ctorArgs)74cdf0e10cSrcweir public Object getInstance(String className, Object[] ctorArgs) 75cdf0e10cSrcweir throws IllegalArgumentException { 76cdf0e10cSrcweir Class[] ctorType = new Class[ctorArgs.length]; 77cdf0e10cSrcweir for(int i=0; i<ctorType.length; i++) { 78cdf0e10cSrcweir ctorType[i] = ctorArgs[i].getClass(); 79cdf0e10cSrcweir } 80cdf0e10cSrcweir return getInstance(className, ctorType, ctorArgs); 81cdf0e10cSrcweir 82cdf0e10cSrcweir } 83cdf0e10cSrcweir 84cdf0e10cSrcweir /** 85cdf0e10cSrcweir * Get an instance of a class. The constructor matching to the 86cdf0e10cSrcweir * given calss types is used and the instance is created using the arguments 87cdf0e10cSrcweir * for the constructor. 88cdf0e10cSrcweir * @param className The class to instantiate. 89cdf0e10cSrcweir * @param ctorClassTypes The class types matching to the constructor. 90cdf0e10cSrcweir * @param ctorArgs Arguments for the constructor. 91cdf0e10cSrcweir * @return The instance of the class. 92cdf0e10cSrcweir */ getInstance(String className, Class[]ctorClassTypes, Object[] ctorArgs)93cdf0e10cSrcweir public Object getInstance(String className, Class[]ctorClassTypes, Object[] ctorArgs) 94cdf0e10cSrcweir throws IllegalArgumentException { 95cdf0e10cSrcweir try { 96cdf0e10cSrcweir Class cls = DynamicClassLoader.forName(className); 97cdf0e10cSrcweir Constructor ctor = cls.getConstructor(ctorClassTypes); 98cdf0e10cSrcweir System.out.println("ctor: " + ctor.getName() + " " + ctor.getModifiers()); 99cdf0e10cSrcweir 100cdf0e10cSrcweir return ctor.newInstance(ctorArgs); 101cdf0e10cSrcweir } catch ( ClassNotFoundException e ) { 102cdf0e10cSrcweir throw new IllegalArgumentException("Couldn't find " + className 103cdf0e10cSrcweir + " " + e); 104cdf0e10cSrcweir } catch ( IllegalAccessException e ) { 105cdf0e10cSrcweir throw new IllegalArgumentException("Couldn't access " + className 106cdf0e10cSrcweir + " " + e); 107cdf0e10cSrcweir } catch ( NoSuchMethodException e ) { 108cdf0e10cSrcweir throw new IllegalArgumentException("Couldn't find constructor for " + className 109cdf0e10cSrcweir + " " + e); 110cdf0e10cSrcweir } catch ( java.lang.reflect.InvocationTargetException e ) { 111cdf0e10cSrcweir e.printStackTrace(); 112cdf0e10cSrcweir throw new IllegalArgumentException("Couldn't invoke " + 113cdf0e10cSrcweir className + " " + e); 114cdf0e10cSrcweir } catch ( InstantiationException e ) { 115cdf0e10cSrcweir throw new IllegalArgumentException("Couldn't instantiate " + 116cdf0e10cSrcweir className + " " + e); 117cdf0e10cSrcweir } 118cdf0e10cSrcweir } 119cdf0e10cSrcweir } 120