/*
* 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 com.sun.script.util;
import javax.script.*;
import java.lang.reflect.*;
import java.security.*;
/*
* java.lang.reflect.Proxy based interface implementor. This is meant
* to be used to implement Invocable.getInterface.
*
* @author Mike Grogan
* @since 1.6
*/
public class InterfaceImplementor {
private Invocable engine;
/** Creates a new instance of Invocable */
public InterfaceImplementor(Invocable engine) {
this.engine = engine;
}
private final class InterfaceImplementorInvocationHandler
implements InvocationHandler {
private Object thiz;
private AccessControlContext accCtxt;
public InterfaceImplementorInvocationHandler(Object thiz,
AccessControlContext accCtxt) {
this.thiz = thiz;
this.accCtxt = accCtxt;
}
public Object invoke(Object proxy , Method method, Object[] args)
throws java.lang.Throwable {
// give chance to convert input args
args = convertArguments(method, args);
Object result;
final Method m = method;
final Object[] a = args;
result = AccessController.doPrivileged(new PrivilegedExceptionAction<Object>() {
public Object run() throws Exception {
if (thiz == null) {
return engine.invokeFunction(m.getName(), a);
} else {
return engine.invokeMethod(thiz, m.getName(), a);
}
}
}, accCtxt);
// give chance to convert the method result
return convertResult(method, result);
}
}
public <T> T getInterface(Object thiz, Class<T> iface)
throws ScriptException {
if (iface == null || !iface.isInterface()) {
throw new IllegalArgumentException("interface Class expected");
}
AccessControlContext accCtxt = AccessController.getContext();
return iface.cast(Proxy.newProxyInstance(iface.getClassLoader(),
new Class[]{iface},
new InterfaceImplementorInvocationHandler(thiz, accCtxt)));
}
// called to convert method result after invoke
protected Object convertResult(Method method, Object res)
throws ScriptException {
// default is identity conversion
return res;
}
// called to convert method arguments before invoke
protected Object[] convertArguments(Method method, Object[] args)
throws ScriptException {
// default is identity conversion
return args;
}
}