Java IO体系

Bertha 。 2022-05-25 09:52 239阅读 0赞

一、[常见I/O][I_O]  
(1)基于字节的IO操作  
![这里写图片描述][70]  
![这里写图片描述][70 1]  
(2)基于字符的IO操作  
![这里写图片描述][70 2]  
![这里写图片描述][70 3]  
(3)总结IO操作  
![这里写图片描述][70 4]  
![这里写图片描述][70 5]  
二、[NIO][]  
![这里写图片描述][70 6]  
![这里写图片描述][70 7]  
举例:  
(1)服务器

package Selector;
    
    import java.net.InetSocketAddress;
    import java.nio.ByteBuffer;
    import java.nio.channels.SelectionKey;
    import java.nio.channels.Selector;
    import java.nio.channels.ServerSocketChannel;
    import java.nio.channels.SocketChannel;
    import java.util.Iterator;
    import java.util.Set;
    
    public class ServerNIO {
    
        public static void main(String[]args){
    
            try{
                ServerSocketChannel ssc=ServerSocketChannel.open();
                ssc.socket().bind(new InetSocketAddress("127.0.0.1",8000));
                ssc.configureBlocking(false);
    
                Selector selector=Selector.open(); //选择器
                //注册channel
                ssc.register(selector,SelectionKey.OP_ACCEPT);
                ByteBuffer readBuff=ByteBuffer.allocate(1024);
                ByteBuffer writeBuff=ByteBuffer.allocate(128);
                writeBuff.put("Received".getBytes());
                writeBuff.flip();
    
                while(true){
                     Set<SelectionKey>keys=selector.selectedKeys();
                     Iterator<SelectionKey>it=keys.iterator();
                     while(it.hasNext()){
                          SelectionKey key=it.next();
                          it.remove();
                          if(key.isAcceptable()){
                              SocketChannel socketChannel=ssc.accept();
                              socketChannel.configureBlocking(false);
                              socketChannel.register(selector, SelectionKey.OP_READ);
    
                          }else if(key.isReadable()){
                              SocketChannel socketChannel=(SocketChannel)key.channel();
                              readBuff.clear();
                              socketChannel.read(readBuff);
                              readBuff.flip();
                              System.out.println("Recieved:"+new String(readBuff.array()));
                              key.interestOps(SelectionKey.OP_WRITE);
                          }else if(key.isWritable()){
                              writeBuff.rewind();
                              SocketChannel socketChannel=(SocketChannel)key.channel();
                              socketChannel.write(writeBuff);
                              key.interestOps(SelectionKey.OP_READ);
                          }
                     }
    
                }
            }catch(Exception e){
    
    
            }
    
        }
    
    }

(2)客户端

package Selector;
    import java.net.InetSocketAddress;
    import java.nio.ByteBuffer;
    import java.nio.channels.SocketChannel;
    
    public class ClientNIO { 
    
        public static void main(String[]args){
              try{
    
                   SocketChannel socketChannel=SocketChannel.open();
                   socketChannel.connect(new InetSocketAddress("127.0.0.1",8000));
                   ByteBuffer writeBuffer=ByteBuffer.allocate(32);
                   ByteBuffer readBuffer=ByteBuffer.allocate(32);
                   writeBuffer.put("Hello World".getBytes());
                   writeBuffer.flip();
                   while(true){
                        writeBuffer.rewind();
                        socketChannel.write(writeBuffer); //通道读数据
                        readBuffer.clear();
                        socketChannel.read(readBuffer);   //通道写数据
                   }
    
              }catch(Exception e){
    
                   System.out.println(e);
              }
        }
    }

三、AIO  
![这里写图片描述][70 8]  
四、[三者对比][Link 1]  
![这里写图片描述][70 9]  
[参考][Link 2]

[I_O]: https://www.cnblogs.com/fysola/p/6123947.html
[70]: /images/20220525/2939506d8b2941ed8ca71fc253b8ab11.png
[70 1]: /images/20220525/28f5ac9a2fec4f7d97f615d53646c4a7.png
[70 2]: /images/20220525/1afe8ad60e32450db49e92f897e84aff.png
[70 3]: /images/20220525/77fe33a4b1234aa5a6a26804b61a7af0.png
[70 4]: /images/20220525/60b3b40f21ba4d29a166d0023618cc66.png
[70 5]: /images/20220525/9004c5088a8d4421be6494ec3e74005a.png
[NIO]: https://www.jianshu.com/p/a33f741fe450
[70 6]: /images/20220525/4c988d69462d471b9b8b0485075e075c.png
[70 7]: /images/20220525/8ee710e91cae447185901f73f1486304.png
[70 8]: /images/20220525/65b0a68417844f3fbb7d0914ab0da4dd.png
[Link 1]: https://blog.csdn.net/anxpp/article/details/51512200
[70 9]: /images/20220525/080a05db7b5c4cf8b72f6c8dcc271b31.png
[Link 2]: https://www.cnblogs.com/diegodu/p/6823855.html