001// Copyright 2011 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007// http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.tapestry5.internal.plastic;
016
017import org.apache.tapestry5.plastic.MethodHandle;
018import org.apache.tapestry5.plastic.MethodInvocationResult;
019
020public class MethodHandleImpl implements MethodHandle
021{
022    private final String className, methodDescription;
023
024    private final int methodIndex;
025
026    protected volatile PlasticClassHandleShim shim;
027
028    public MethodHandleImpl(String className, String methodDescription, int methodIndex)
029    {
030        this.className = className;
031        this.methodDescription = methodDescription;
032        this.methodIndex = methodIndex;
033    }
034
035    @Override
036    public String toString()
037    {
038        return String.format("MethodHandle[%s %s]", className, methodDescription);
039    }
040
041    @Override
042    public MethodInvocationResult invoke(Object instance, Object... arguments)
043    {
044
045        if (instance == null)
046            throw new NullPointerException(String.format(
047                    "Unable to invoke method %s of class %s, as provided instance is null.", methodDescription,
048                    className));
049
050        return shim.invoke(instance, methodIndex, arguments);
051    }
052
053}