/*
* Copyright (c) 2009, 2015, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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/*
* This file is available under and governed by the GNU General Public
* License version 2 only, as published by the Free Software Foundation.
* However, the following notice accompanied the original version of this
* file:
*
* The MIT License
*
* Copyright (c) 2004-2014 Paul R. Holser, Jr.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package jdk.internal.joptsimple.internal;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import static java.lang.reflect.Modifier.*;
import jdk.internal.joptsimple.ValueConverter;
import static jdk.internal.joptsimple.internal.Classes.*;
/**
* Helper methods for reflection.
*
* @author <a href="mailto:pholser@alumni.rice.edu">Paul Holser</a>
*/
public final class Reflection {
private Reflection() {
throw new UnsupportedOperationException();
}
/**
* Finds an appropriate value converter for the given class.
*
* @param <V> a constraint on the class object to introspect
* @param clazz class to introspect on
* @return a converter method or constructor
*/
public static <V> ValueConverter<V> findConverter( Class<V> clazz ) {
Class<V> maybeWrapper = wrapperOf( clazz );
ValueConverter<V> valueOf = valueOfConverter( maybeWrapper );
if ( valueOf != null )
return valueOf;
ValueConverter<V> constructor = constructorConverter( maybeWrapper );
if ( constructor != null )
return constructor;
throw new IllegalArgumentException( clazz + " is not a value type" );
}
private static <V> ValueConverter<V> valueOfConverter( Class<V> clazz ) {
try {
Method valueOf = clazz.getDeclaredMethod( "valueOf", String.class );
if ( meetsConverterRequirements( valueOf, clazz ) )
return new MethodInvokingValueConverter<V>( valueOf, clazz );
return null;
}
catch ( NoSuchMethodException ignored ) {
return null;
}
}
private static <V> ValueConverter<V> constructorConverter( Class<V> clazz ) {
try {
return new ConstructorInvokingValueConverter<V>( clazz.getConstructor( String.class ) );
}
catch ( NoSuchMethodException ignored ) {
return null;
}
}
/**
* Invokes the given constructor with the given arguments.
*
* @param <T> constraint on the type of the objects yielded by the constructor
* @param constructor constructor to invoke
* @param args arguments to hand to the constructor
* @return the result of invoking the constructor
* @throws ReflectionException in lieu of the gaggle of reflection-related exceptions
*/
public static <T> T instantiate( Constructor<T> constructor, Object... args ) {
try {
return constructor.newInstance( args );
}
catch ( Exception ex ) {
throw reflectionException( ex );
}
}
/**
* Invokes the given static method with the given arguments.
*
* @param method method to invoke
* @param args arguments to hand to the method
* @return the result of invoking the method
* @throws ReflectionException in lieu of the gaggle of reflection-related exceptions
*/
public static Object invoke( Method method, Object... args ) {
try {
return method.invoke( null, args );
}
catch ( Exception ex ) {
throw reflectionException( ex );
}
}
@SuppressWarnings( "unchecked" )
public static <V> V convertWith( ValueConverter<V> converter, String raw ) {
return converter == null ? (V) raw : converter.convert( raw );
}
private static boolean meetsConverterRequirements( Method method, Class<?> expectedReturnType ) {
int modifiers = method.getModifiers();
return isPublic( modifiers ) && isStatic( modifiers ) && expectedReturnType.equals( method.getReturnType() );
}
private static RuntimeException reflectionException( Exception ex ) {
if ( ex instanceof IllegalArgumentException )
return new ReflectionException( ex );
if ( ex instanceof InvocationTargetException )
return new ReflectionException( ex.getCause() );
if ( ex instanceof RuntimeException )
return (RuntimeException) ex;
return new ReflectionException( ex );
}
}