Channel~scatter and gather

*介绍

---GatheringByteChannel和ScatteringByteChannel接口,实现对有序字节数组的读取,使得协议数据和固定数组内容的处理更加方便.

---实现类

DatagramChannel,SocketChannel,FileChannel,SinkChannel

---GatheringByteChannel,long write(ByteBuffer[] srcs, int offset, int length)

srcs,数据来源; offset,srcs数组的偏移量; length,获取最大srcs的个数.

long,返回写入的个数.

---ScatteringByteChannel,long read(ByteBuffer[] dsts, int offset, int length)

dsts,要写入的数组; offset,开始使用的buffer位置;  length,使用的最大buffer数

*示例,

/**
 * Feb 23, 2011 by dzh
 */
package channel;

import java.io.File;
import java.io.FileOutputStream;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;

/**
 * @author dzh
 * 协议,name[名字]|sex[性别],分隔符"|"
 * 获取数据,去除分割符,写入person.txt文件
 */
public class ChannelGatherTest {
	
	private static final String SEPERATOR ="\\|";
	private static final String ENCODING ="utf-8";
	private static final String DATA ="戴忠|男";	//源数据
	private static final String TPATH ="/home/dzh/gather.txt"; //文件路径
	
	public static void main(String[] args) throws Exception {
		ByteBuffer[] bufs =scatterData();
		gatherData(bufs);
	}
	
	private static void gatherData(ByteBuffer[] bufs) throws Exception{
		File file =new File(TPATH);
		if(!file.exists())
			file.createNewFile();
		FileOutputStream fos =new FileOutputStream(file);
		FileChannel fc =fos.getChannel();
		while(fc.write(bufs)>0){
			//do others
		};
		fos.close();
	}
	
	private static ByteBuffer[] scatterData() throws Exception{
		String[] data =DATA.split(SEPERATOR);
		ByteBuffer nameBuf =ByteBuffer.wrap(data[0].getBytes(ENCODING));
		ByteBuffer sexBuf =ByteBuffer.wrap(data[1].getBytes(ENCODING));
		return new ByteBuffer[]{nameBuf,sexBuf};
	}
	
}