com.nanxiaoqiang.test.netty.protocol.demo1.codec.NettyMessageEncoder.java Source code

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Here is the source code for com.nanxiaoqiang.test.netty.protocol.demo1.codec.NettyMessageEncoder.java

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/*
 * Copyright 2013-2018 Lilinfeng.
 *  
 * Licensed 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 com.nanxiaoqiang.test.netty.protocol.demo1.codec;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToByteEncoder;

import java.io.IOException;
import java.util.Map;

import com.nanxiaoqiang.test.netty.protocol.demo1.struct.NettyMessage;

/**
 * @author Lilinfeng
 * @date 2014314
 * @version 1.0
 */
public final class NettyMessageEncoder extends MessageToByteEncoder<NettyMessage> {

    MarshallingEncoder marshallingEncoder;

    public NettyMessageEncoder() throws IOException {
        this.marshallingEncoder = new MarshallingEncoder();
    }

    @Override
    protected void encode(ChannelHandlerContext ctx, NettyMessage msg, ByteBuf sendBuf) throws Exception {
        if (msg == null || msg.getHeader() == null)
            throw new Exception("The encode message is null");
        // Header Start
        sendBuf.writeInt((msg.getHeader().getCrcCode()));// crc
        sendBuf.writeInt((msg.getHeader().getLength()));// ?
        sendBuf.writeLong((msg.getHeader().getSessionID()));
        sendBuf.writeByte((msg.getHeader().getType()));
        sendBuf.writeByte((msg.getHeader().getPriority()));
        sendBuf.writeInt((msg.getHeader().getAttachment().size()));
        String key = null;
        byte[] keyArray = null;
        Object value = null;
        for (Map.Entry<String, Object> param : msg.getHeader().getAttachment().entrySet()) {
            key = param.getKey();
            keyArray = key.getBytes("UTF-8");
            sendBuf.writeInt(keyArray.length);
            sendBuf.writeBytes(keyArray);
            value = param.getValue();
            marshallingEncoder.encode(value, sendBuf);
        }
        key = null;
        keyArray = null;
        value = null;
        // Head End

        // Body Start
        if (msg.getBody() != null) {// ?
            marshallingEncoder.encode(msg.getBody(), sendBuf);
        } else
            // ?
            sendBuf.writeInt(0);// 0int
        sendBuf.setInt(4, sendBuf.readableBytes() - 8);// 0~3CRC4~7??8?
    }
    // Body End
}