001// Copyright 2004, 2005 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.tapestry.util.io;
016
017import java.io.IOException;
018import java.io.InputStream;
019import java.io.ObjectInputStream;
020import java.io.ObjectStreamClass;
021
022import org.apache.hivemind.ClassResolver;
023import org.apache.hivemind.util.Defense;
024
025/**
026 * Specialized subclass of {@link java.io.ObjectInputStream}that knows how to resolve classes with
027 * a non-default class loader (represented by an instance of
028 * {@link org.apache.hivemind.ClassResolver}).
029 * 
030 * @author Howard Lewis Ship
031 * @since 3.0
032 */
033
034public class ResolvingObjectInputStream extends ObjectInputStream
035{
036    private ClassResolver _resolver;
037
038    public ResolvingObjectInputStream(ClassResolver resolver, InputStream input) throws IOException
039    {
040        super(input);
041
042        Defense.notNull(resolver, "resolver");
043
044        _resolver = resolver;
045    }
046
047    /**
048     * Overrides the default implementation to have the resource resolver find the class.
049     */
050
051    protected Class resolveClass(ObjectStreamClass v) throws IOException, ClassNotFoundException
052    {
053        return _resolver.findClass(v.getName());
054    }
055}