1 /* 2 * Copyright (c) 2008, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 package com.sun.beans.finder; 26 27 import com.sun.beans.util.Cache; 28 29 import java.lang.reflect.Constructor; 30 import java.lang.reflect.Modifier; 31 32 import static com.sun.beans.util.Cache.Kind.SOFT; 33 import static sun.reflect.misc.ReflectUtil.isPackageAccessible; 34 35 /** 36 * This utility class provides {@code static} methods 37 * to find a public constructor with specified parameter types 38 * in specified class. 39 * 40 * @since 1.7 41 * 42 * @author Sergey A. Malenkov 43 */ 44 public final class ConstructorFinder extends AbstractFinder<Constructor<?>> { 45 private static final Cache<Signature, Constructor<?>> CACHE = new Cache<Signature, Constructor<?>>(SOFT, SOFT) { 46 @Override 47 public Constructor create(Signature signature) { 48 try { 49 ConstructorFinder finder = new ConstructorFinder(signature.getArgs()); 50 return finder.find(signature.getType().getConstructors()); 51 } 52 catch (Exception exception) { 53 throw new SignatureException(exception); 54 } 55 } 56 }; 57 58 /** 59 * Finds public constructor 60 * that is declared in public class. 61 * 62 * @param type the class that can have constructor 63 * @param args parameter types that is used to find constructor 64 * @return object that represents found constructor 65 * @throws NoSuchMethodException if constructor could not be found 66 * or some constructors are found 67 */ 68 public static Constructor<?> findConstructor(Class<?> type, Class<?>...args) throws NoSuchMethodException { 69 if (type.isPrimitive()) { 70 throw new NoSuchMethodException("Primitive wrapper does not contain constructors"); 71 } 72 if (type.isInterface()) { 73 throw new NoSuchMethodException("Interface does not contain constructors"); 74 } 75 if (Modifier.isAbstract(type.getModifiers())) { 76 throw new NoSuchMethodException("Abstract class cannot be instantiated"); 77 } 78 if (!Modifier.isPublic(type.getModifiers()) || !isPackageAccessible(type)) { 79 throw new NoSuchMethodException("Class is not accessible"); 80 } 81 PrimitiveWrapperMap.replacePrimitivesWithWrappers(args); 82 Signature signature = new Signature(type, args); 83 84 try { 85 return CACHE.get(signature); 86 } 87 catch (SignatureException exception) { 88 throw exception.toNoSuchMethodException("Constructor is not found"); 89 } 90 } 91 92 /** 93 * Creates constructor finder with specified array of parameter types. 94 * 95 * @param args the array of parameter types 96 */ 97 private ConstructorFinder(Class<?>[] args) { 98 super(args); 99 } 100 }