/*
* Copyright (c) 2005, 2006, 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
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.swing;
import java.security.*;
import java.lang.reflect.*;
/**
* A utility for accessing and invoking methods, via reflection,
* that would otherwise be unaccessible.
*
* @author Shannon Hickey
*/
public class AccessibleMethod {
private final Method method;
/**
* Construct an instance for the given params.
*
* @param klass the class to which the method belongs
* @param methodName the name of the method
* @param paramTypes the paramater type array
* @throws NullPointerException if <code>klass</code>
* or <code>name</code> is <code>null</code>
* @throws NoSuchMethodException if the method can't be found
*/
public AccessibleMethod(Class klass,
String methodName,
Class ... paramTypes) throws NoSuchMethodException {
try {
method = AccessController.doPrivileged(
new AccessMethodAction(klass, methodName, paramTypes));
} catch (PrivilegedActionException e) {
throw (NoSuchMethodException)e.getCause();
}
}
/**
* Invoke the method that this object represents.
* Has the same behavior and throws the same exceptions as
* <code>java.lang.reflect.Method.invoke</code> with one
* exception: This method does not throw
* <code>IllegalAccessException</code> since the target
* method has already been made accessible.
*
* @param obj the object the underlying method is invoked from
* @param args the arguments used for the method call
* @return the result of dispatching the method represented by
* this object on <code>obj</code> with parameters
* <code>args</code>
* @see java.lang.reflect.Method#invoke
*/
public Object invoke(Object obj, Object ... args)
throws IllegalArgumentException, InvocationTargetException {
try {
return method.invoke(obj, args);
} catch (IllegalAccessException e) {
// should never happen since we've made it accessible
throw new AssertionError("accessible method inaccessible");
}
}
/**
* Invoke the method that this object represents, with the
* expectation that the method being called throws no
* checked exceptions.
* <p>
* Simply calls <code>this.invoke(obj, args)</code>
* but catches any <code>InvocationTargetException</code>
* and returns the cause wrapped in a runtime exception.
*
* @param obj the object the underlying method is invoked from
* @param args the arguments used for the method call
* @return the result of dispatching the method represented by
* this object on <code>obj</code> with parameters
* <code>args</code>
* @see #invoke
*/
public Object invokeNoChecked(Object obj, Object ... args) {
try {
return invoke(obj, args);
} catch (InvocationTargetException ex) {
if (ex.getCause() instanceof RuntimeException) {
throw (RuntimeException)ex.getCause();
} else {
throw new RuntimeException(ex.getCause());
}
}
}
/** The action used to fetch the method and make it accessible */
private static class AccessMethodAction implements PrivilegedExceptionAction<Method> {
private final Class klass;
private final String methodName;
private final Class[] paramTypes;
public AccessMethodAction(Class klass,
String methodName,
Class ... paramTypes) {
this.klass = klass;
this.methodName = methodName;
this.paramTypes = paramTypes;
}
public Method run() throws NoSuchMethodException {
Method method = klass.getDeclaredMethod(methodName, paramTypes);
method.setAccessible(true);
return method;
}
}
}