分散读取与聚集写入

港控/mmm° 2022-01-28 11:15 287阅读 0赞

# [分散读取与聚集写入][Link 1] #

## 分散读取与聚集写入 ##

*分散读取(scattering Reads)：将通道中的数据分散到多个缓冲区中*

*![1179709-20181108230550845-1650642311.png][]*

*聚集写入(gathering Writes)：将多个缓冲区的数据聚集到通道中*

![1179709-20181108230640289-1120498326.png][]

package com.toov5.Nio;
    
    import java.io.IOException;
    import java.io.RandomAccessFile;
    import java.nio.ByteBuffer;
    import java.nio.channels.FileChannel;
    
    public class BufferTest03 {
       public static void main(String[] args) throws IOException {
           //随机访问
         RandomAccessFile raf = new RandomAccessFile("test.txt", "rw");
         //拿到通道
          FileChannel channel = raf.getChannel();
          //分配制定大小缓冲区
          ByteBuffer buffer1 = ByteBuffer.allocate(100);
          ByteBuffer buffer2 = ByteBuffer.allocate(1024);
          //分散读取
          ByteBuffer[] buffers = {buffer1,buffer2}; 
          //通道里面进行读取
           channel.read(buffers);
           //写入完毕之后 for 循环
           for(ByteBuffer byteBuffer : buffers) {
              //切换成读的模式
               byteBuffer.flip();
                
           }
           System.out.println(new String(buffers[0].array(),0,buffers[0].limit()));
           System.out.println("*****************************************");
           System.out.println(new String(buffers[1].array(),1,buffers[1].limit()));
           System.out.println(".....聚集读取.........");
           RandomAccessFile randomAccessFile = new RandomAccessFile("test2.txt", "rw");
           //获取通道
           FileChannel channel2 = randomAccessFile.getChannel();
           channel2.write(buffers);
           randomAccessFile.close();
           raf.close();
    }
    }

![1179709-20181108232429986-464730275.png][]

![1179709-20181108232400670-1049820342.png][]

分散读取 聚集写入

[Link 1]: https://www.cnblogs.com/toov5/p/9932751.html
[1179709-20181108230550845-1650642311.png]: /images/20220128/20650e82e3f945f0874e4d8bd993f70e.png
[1179709-20181108230640289-1120498326.png]: /images/20220128/33a700a0a98c4ae693ca0386073dc0fa.png
[1179709-20181108232429986-464730275.png]: /images/20220128/b96b649b1c9246f89363010385ddbf7d.png
[1179709-20181108232400670-1049820342.png]: /images/20220128/0c3895b816954048847121f89eefed15.png