JAVA高级基础（49）---分散读取和聚集写入

分散读取和聚集写入

1. read(ByteBuffer[] bufs);   //分散读取
2. write(ByteBuffer[] bufs);   //聚集写入

分散读取（Scattering Reads）是指从Channle中读取的数据“分散”到多个Buffer中

注意：按照缓冲区的顺序，从Channle中读取的数据依次将Buffer填满

聚集写入（Gathering Writes）是指将多个Buffer中的数据“聚集”到Channle

注意：按照缓冲区的顺序，写入 position 和 limit 之间的数据到 Channle

package org.lanqiao.channel.demo;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;

/*
 * 分散读取和聚集写入
 */
public class ChannelDemo {
	public static void main(String[] args) throws IOException {
		//开辟通道：
		RandomAccessFile raf = new  RandomAccessFile("Notes.txt","rw");
		RandomAccessFile rafOut = new RandomAccessFile("copy.txt", "rw");
		FileChannel inChannel = raf.getChannel();
		FileChannel outChannel = rafOut.getChannel();
		//分配缓冲区：
		ByteBuffer buf1 = ByteBuffer.allocate(100);
		ByteBuffer buf2 = ByteBuffer.allocate(1024);
		ByteBuffer buf3 = ByteBuffer.allocate(100);
		ByteBuffer[] bufs = {buf1 , buf2,buf3};
		
		while((inChannel.read(bufs)) != -1) {
			for(ByteBuffer bb :bufs) {
				bb.flip();
				System.out.println(new String(bb.array(),0,bb.limit()));
				bb.clear();
				System.out.println("-------------------------------------");
				
			}
			System.out.println("++++++++++++++++++++++++++");
		}
		/*//进行读操作
		while((inChannel.read(bufs)) != -1) {
			for(ByteBuffer bb :bufs) {
				bb.flip();
				outChannel.write(bb);
				bb.clear();
				
			}
			
		}*/
		inChannel.close();
		outChannel.close();	
	}
}