ControlMessage.java

package org.act.tstream.message.netty;

import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBufferOutputStream;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.Channel;

enum ControlMessage {
	EOB_MESSAGE((short) -201), OK_RESPONSE((short) -200);

	private short code;
	private long timeStamp;

	// private constructor
	private ControlMessage(short code) {
		this.code = code;
	}

	/**
	 * Return a control message per an encoded status code
	 * 
	 * @param encoded
	 * @return
	 */
	static ControlMessage mkMessage(short encoded) {
		for (ControlMessage cm : ControlMessage.values()) {
			if (encoded == cm.code)
				return cm;
		}
		return null;
	}

	int encodeLength() {
		return 10; // short + long
	}

	/**
	 * encode the current Control Message into a channel buffer
	 * 
	 * @throws Exception
	 */
	ChannelBuffer buffer() throws Exception {
		ChannelBufferOutputStream bout = new ChannelBufferOutputStream(
				ChannelBuffers.directBuffer(encodeLength()));
		write(bout);
		bout.close();
		return bout.buffer();
	}

	void write(ChannelBufferOutputStream bout) throws Exception {
		bout.writeShort(code);
		bout.writeLong(System.currentTimeMillis());
	}
	
	long getTimeStamp() {
		return timeStamp;
	}
	
	void setTimeStamp(long timeStamp) {
		this.timeStamp = timeStamp;
	}
}