6、NIO--分散读取与聚集写入

//分散读取和聚集写入
    @Test
    public void test7() throws IOException {
        
        RandomAccessFile raf = new RandomAccessFile("d:\\a.txt","rw");
        
        //1、获取通道
        FileChannel fileChannel = raf.getChannel();
        
        //2、分配指定大小的缓冲区
        ByteBuffer buf1= ByteBuffer.allocate(20);
        ByteBuffer buf2 = ByteBuffer.allocate(200);
        
        //3、分散读取
        ByteBuffer [] bufs = {buf1,buf2};
        //read(ByteBuffer[] dsts) 
        fileChannel.read(bufs);
        
        for(ByteBuffer b : bufs){
            b.flip();
        }
        
        System.out.println(new String(bufs[0].array(),0,bufs[0].limit()));
        System.out.println(new String(bufs[1].array(),0,bufs[1].limit()));
        
        //聚集写入
        RandomAccessFile raf2 = new RandomAccessFile("d:\\aa.txt", "rw");
        FileChannel fileChannel2 = raf2.getChannel();
        //write(ByteBuffer[] srcs)
        fileChannel2.write(bufs);
        
    }