lightning-core/src/main/java/org/apache/directmemory/lightning/internal/instantiator/gcj/GCJInstantiatorBase.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.directmemory.lightning.internal.instantiator.gcj;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.lang.reflect.Method;

import org.apache.directmemory.lightning.instantiator.ObjectInstantiator;
import org.apache.directmemory.lightning.internal.instantiator.ObjenesisException;

/**
 * Base class for GCJ-based instantiators. It initializes reflection access to method ObjectInputStream.newObject, as
 * well as creating a dummy ObjectInputStream to be used as the "this" argument for the method.
 * 
 * @author Leonardo Mesquita
 */
public abstract class GCJInstantiatorBase
    implements ObjectInstantiator
{

    static Method newObjectMethod = null;

    static ObjectInputStream dummyStream;

    private static class DummyStream
        extends ObjectInputStream
    {

        public DummyStream()
            throws IOException
        {
        }
    }

    private static void initialize()
    {
        if ( newObjectMethod == null )
        {
            try
            {
                newObjectMethod =
                    ObjectInputStream.class.getDeclaredMethod( "newObject", new Class[] { Class.class, Class.class } );
                newObjectMethod.setAccessible( true );
                dummyStream = new DummyStream();
            }
            catch ( RuntimeException e )
            {
                throw new ObjenesisException( e );
            }
            catch ( NoSuchMethodException e )
            {
                throw new ObjenesisException( e );
            }
            catch ( IOException e )
            {
                throw new ObjenesisException( e );
            }
        }
    }

    protected final Class<?> type;

    public GCJInstantiatorBase( Class<?> type )
    {
        this.type = type;
        initialize();
    }

    @Override
    public abstract Object newInstance();
}