1 /* 2 * Copyright (c) 2009, 2015, 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 26 /* 27 * This file is available under and governed by the GNU General Public 28 * License version 2 only, as published by the Free Software Foundation. 29 * However, the following notice accompanied the original version of this 30 * file: 31 * 32 * The MIT License 33 * 34 * Copyright (c) 2004-2015 Paul R. Holser, Jr. 35 * 36 * Permission is hereby granted, free of charge, to any person obtaining 37 * a copy of this software and associated documentation files (the 38 * "Software"), to deal in the Software without restriction, including 39 * without limitation the rights to use, copy, modify, merge, publish, 40 * distribute, sublicense, and/or sell copies of the Software, and to 41 * permit persons to whom the Software is furnished to do so, subject to 42 * the following conditions: 43 * 44 * The above copyright notice and this permission notice shall be 45 * included in all copies or substantial portions of the Software. 46 * 47 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 48 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 49 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 50 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 51 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 52 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 53 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 54 */ 55 56 package jdk.internal.joptsimple.internal; 57 58 import java.lang.reflect.Constructor; 59 import java.lang.reflect.InvocationTargetException; 60 import java.lang.reflect.Method; 61 62 import static java.lang.reflect.Modifier.*; 63 64 import jdk.internal.joptsimple.ValueConverter; 65 66 import static jdk.internal.joptsimple.internal.Classes.*; 67 68 /** 69 * Helper methods for reflection. 70 * 71 * @author <a href="mailto:pholser@alumni.rice.edu">Paul Holser</a> 72 */ 73 public final class Reflection { Reflection()74 private Reflection() { 75 throw new UnsupportedOperationException(); 76 } 77 78 /** 79 * Finds an appropriate value converter for the given class. 80 * 81 * @param <V> a constraint on the class object to introspect 82 * @param clazz class to introspect on 83 * @return a converter method or constructor 84 */ findConverter( Class<V> clazz )85 public static <V> ValueConverter<V> findConverter( Class<V> clazz ) { 86 Class<V> maybeWrapper = wrapperOf( clazz ); 87 88 ValueConverter<V> valueOf = valueOfConverter( maybeWrapper ); 89 if ( valueOf != null ) 90 return valueOf; 91 92 ValueConverter<V> constructor = constructorConverter( maybeWrapper ); 93 if ( constructor != null ) 94 return constructor; 95 96 throw new IllegalArgumentException( clazz + " is not a value type" ); 97 } 98 valueOfConverter( Class<V> clazz )99 private static <V> ValueConverter<V> valueOfConverter( Class<V> clazz ) { 100 try { 101 Method valueOf = clazz.getMethod( "valueOf", String.class ); 102 if ( meetsConverterRequirements( valueOf, clazz ) ) 103 return new MethodInvokingValueConverter<>( valueOf, clazz ); 104 105 return null; 106 } catch ( NoSuchMethodException ignored ) { 107 return null; 108 } 109 } 110 constructorConverter( Class<V> clazz )111 private static <V> ValueConverter<V> constructorConverter( Class<V> clazz ) { 112 try { 113 return new ConstructorInvokingValueConverter<>( clazz.getConstructor( String.class ) ); 114 } catch ( NoSuchMethodException ignored ) { 115 return null; 116 } 117 } 118 119 /** 120 * Invokes the given constructor with the given arguments. 121 * 122 * @param <T> constraint on the type of the objects yielded by the constructor 123 * @param constructor constructor to invoke 124 * @param args arguments to hand to the constructor 125 * @return the result of invoking the constructor 126 * @throws ReflectionException in lieu of the gaggle of reflection-related exceptions 127 */ instantiate( Constructor<T> constructor, Object... args )128 public static <T> T instantiate( Constructor<T> constructor, Object... args ) { 129 try { 130 return constructor.newInstance( args ); 131 } catch ( Exception ex ) { 132 throw reflectionException( ex ); 133 } 134 } 135 136 /** 137 * Invokes the given static method with the given arguments. 138 * 139 * @param method method to invoke 140 * @param args arguments to hand to the method 141 * @return the result of invoking the method 142 * @throws ReflectionException in lieu of the gaggle of reflection-related exceptions 143 */ invoke( Method method, Object... args )144 public static Object invoke( Method method, Object... args ) { 145 try { 146 return method.invoke( null, args ); 147 } catch ( Exception ex ) { 148 throw reflectionException( ex ); 149 } 150 } 151 152 @SuppressWarnings( "unchecked" ) convertWith( ValueConverter<V> converter, String raw )153 public static <V> V convertWith( ValueConverter<V> converter, String raw ) { 154 return converter == null ? (V) raw : converter.convert( raw ); 155 } 156 meetsConverterRequirements( Method method, Class<?> expectedReturnType )157 private static boolean meetsConverterRequirements( Method method, Class<?> expectedReturnType ) { 158 int modifiers = method.getModifiers(); 159 return isPublic( modifiers ) && isStatic( modifiers ) && expectedReturnType.equals( method.getReturnType() ); 160 } 161 reflectionException( Exception ex )162 private static RuntimeException reflectionException( Exception ex ) { 163 if ( ex instanceof IllegalArgumentException ) 164 return new ReflectionException( ex ); 165 if ( ex instanceof InvocationTargetException ) 166 return new ReflectionException( ex.getCause() ); 167 if ( ex instanceof RuntimeException ) 168 return (RuntimeException) ex; 169 170 return new ReflectionException( ex ); 171 } 172 } 173