netty5/codec/src/main/java/io/netty/handler/codec/marshalling/MarshallingDecoder.java

84 lines
3.0 KiB
Java

/*
* Copyright 2012 The Netty Project
*
* The Netty Project 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 io.netty.handler.codec.marshalling;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
import io.netty.handler.codec.TooLongFrameException;
import org.jboss.marshalling.ByteInput;
import org.jboss.marshalling.Unmarshaller;
import java.io.StreamCorruptedException;
/**
* Decoder which MUST be used with {@link MarshallingEncoder}.
*
* A {@link LengthFieldBasedFrameDecoder} which use an {@link Unmarshaller} to read the Object out
* of the {@link ByteBuf}.
*
*/
public class MarshallingDecoder extends LengthFieldBasedFrameDecoder {
private final UnmarshallerProvider provider;
/**
* Creates a new decoder whose maximum object size is {@code 1048576}
* bytes. If the size of the received object is greater than
* {@code 1048576} bytes, a {@link StreamCorruptedException} will be
* raised.
*
*/
public MarshallingDecoder(UnmarshallerProvider provider) {
this(provider, 1048576);
}
/**
* Creates a new decoder with the specified maximum object size.
*
* @param maxObjectSize the maximum byte length of the serialized object.
* if the length of the received object is greater
* than this value, {@link TooLongFrameException}
* will be raised.
*/
public MarshallingDecoder(UnmarshallerProvider provider, int maxObjectSize) {
super(maxObjectSize, 0, 4, 0, 4);
this.provider = provider;
}
@Override
protected Object decode0(ChannelHandlerContext ctx, ByteBuf in) throws Exception {
ByteBuf frame = (ByteBuf) super.decode0(ctx, in);
if (frame == null) {
return null;
}
// Call close in a finally block as the ReplayingDecoder will throw an Error if not enough bytes are
// readable. This helps to be sure that we do not leak resource
try (Unmarshaller unmarshaller = provider.getUnmarshaller(ctx)) {
ByteInput input = new ChannelBufferByteInput(frame);
unmarshaller.start(input);
Object obj = unmarshaller.readObject();
unmarshaller.finish();
return obj;
}
}
@Override
protected ByteBuf extractFrame(ChannelHandlerContext ctx, ByteBuf buffer, int index, int length) {
return buffer.slice(index, length);
}
}