BIO,NIO,AIO  Netty 


- [BIO,NIO,AIO ](#bionioaio-)
  - [1. BIO \(Blocking I/O\)](#1-bio-blocking-io)
    - [1.1  BIO](#11--bio)
    - [1.2  IO](#12--io)
    - [1.3 ](#13-)
    - [1.4 ](#14-)
  - [2. NIO \(New I/O\)](#2-nio-new-io)
    - [2.1 NIO ](#21-nio-)
    - [2.2 NIO/NIOIO](#22-nionioio)
      - [1)Non-blocking IOIO](#1non-blocking-ioio)
      - [2)Buffer\(\)](#2buffer)
      - [3)Channel \(\)](#3channel-)
      - [4)Selectors\(\)](#4selectors)
    - [2.3  NIO ](#23-nio-)
    - [2.4 NIO](#24-nio)
    - [2.5 ](#25-)
  - [3. AIO  \(Asynchronous I/O\)](#3-aio-asynchronous-io)
  - [](#)


# BIO,NIO,AIO 

 Java  BIONIO AIO  Java  IO  API JavaAPI

 BIO,NIO,AIO 

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## 1. BIO (Blocking I/O)

I/O

### 1.1  BIO

BIO()

![BIO](https://my-blog-to-use.oss-cn-beijing.aliyuncs.com/2.png)

 **BIO **  Acceptor `while(true)`  `accept()`  

 **BIO ** `socket.accept()``socket.read()``socket.write()`  ****  **** `FixedThreadPool` N():M()I/ON  M" BIO"

****

 Java  Linux 

### 1.2  IO

I/OMNMN.

IO()

![IO](https://my-blog-to-use.oss-cn-beijing.aliyuncs.com/3.png)

 I/O  Socket Taskjava.lang.RunnableJDK  N 

I/OBIO

### 1.3 

BIO"+:hello world"        

[https://www.jianshu.com/p/a4e03835921a](https://www.jianshu.com/p/a4e03835921a)

****

```java
/**
 * 
 * @author 
 * @date 20181014
 * @Description:
 */
public class IOClient {

  public static void main(String[] args) {
    // TODO 
    new Thread(() -> {
      try {
        Socket socket = new Socket("127.0.0.1", 3333);
        while (true) {
          try {
            socket.getOutputStream().write((new Date() + ": hello world").getBytes());
            Thread.sleep(2000);
          } catch (Exception e) {
          }
        }
      } catch (IOException e) {
      }
    }).start();

  }

}

```

****

```java
/**
 * @author 
 * @date 20181014
 * @Description: 
 */
public class IOServer {

  public static void main(String[] args) throws IOException {
    // TODO 
    ServerSocket serverSocket = new ServerSocket(3333);

    // 
    new Thread(() -> {
      while (true) {
        try {
          // 
          Socket socket = serverSocket.accept();

          // 
          new Thread(() -> {
            try {
              int len;
              byte[] data = new byte[1024];
              InputStream inputStream = socket.getInputStream();
              // 
              while ((len = inputStream.read(data)) != -1) {
                System.out.println(new String(data, 0, len));
              }
            } catch (IOException e) {
            }
          }).start();

        } catch (IOException e) {
        }

      }
    }).start();

  }

}
```

### 1.4 

1000 I/O  BIO  I/O 


## 2. NIO (New I/O)

### 2.1 NIO 

 NIOI/OJava 1.4 NIO java.nio  Channel , SelectorBuffer
 
NIONNon-blockingNewI/O NIOBIO `Socket`  `ServerSocket`  `SocketChannel`  `ServerSocketChannel` ,I/O NIO 

### 2.2 NIO/NIOIO

 NIO  IO  IO  IO  NIO 3/ NIO  NIO 

#### 1)Non-blocking IOIO

**IONIO**

Java NIOIObufferbuffer

Java IO `read()`   `write()` 

#### 2)Buffer()

**IO (Stream oriented) NIO (Buffer oriented)**

BufferNIOBufferI/OI/O Stream  Stream  Buffer  NIO  Buffer 

NIO; NIO

 ByteBuffer, ByteBuffer  byte ByteBuffer,JavaBoolean

#### 3)Channel ()

NIO Channel 

Buffer Buffer

#### 4)Selector ()

NIOIO

 

![Selector3Channel](https://my-blog-to-use.oss-cn-beijing.aliyuncs.com/2019-2/Slector.png)

### 2.3  NIO 
NIOIO Channel 

-  
-  



![NIO](https://my-blog-to-use.oss-cn-beijing.aliyuncs.com/2019-2/NIO.png)


### 2.4 NIO

NIO 

- Channel()
- Buffer()
- Selector()

NIONIOAPI

### 2.5 

        

[https://www.jianshu.com/p/a4e03835921a](https://www.jianshu.com/p/a4e03835921a)

 IOClient.java  NIO 

```java
/**
 * 
 * @author 
 * @date 2019221
 * @Description: NIO 
 */
public class NIOServer {
  public static void main(String[] args) throws IOException {
    // 1. serverSelector
    // clientSelector IO  1w  while 
    Selector serverSelector = Selector.open();
    // 2. clientSelector
    Selector clientSelector = Selector.open();

    new Thread(() -> {
      try {
        // IO
        ServerSocketChannel listenerChannel = ServerSocketChannel.open();
        listenerChannel.socket().bind(new InetSocketAddress(3333));
        listenerChannel.configureBlocking(false);
        listenerChannel.register(serverSelector, SelectionKey.OP_ACCEPT);

        while (true) {
          // 1 1ms
          if (serverSelector.select(1) > 0) {
            Set set = serverSelector.selectedKeys();
            Iterator keyIterator = set.iterator();

            while (keyIterator.hasNext()) {
              SelectionKey key = keyIterator.next();

              if (key.isAcceptable()) {
                try {
                  // (1) clientSelector
                  SocketChannel clientChannel = ((ServerSocketChannel) key.channel()).accept();
                  clientChannel.configureBlocking(false);
                  clientChannel.register(clientSelector, SelectionKey.OP_READ);
                } finally {
                  keyIterator.remove();
                }
              }

            }
          }
        }
      } catch (IOException ignored) {
      }
    }).start();
    new Thread(() -> {
      try {
        while (true) {
          // (2) 1 1ms
          if (clientSelector.select(1) > 0) {
            Set set = clientSelector.selectedKeys();
            Iterator keyIterator = set.iterator();

            while (keyIterator.hasNext()) {
              SelectionKey key = keyIterator.next();

              if (key.isReadable()) {
                try {
                  SocketChannel clientChannel = (SocketChannel) key.channel();
                  ByteBuffer byteBuffer = ByteBuffer.allocate(1024);
                  // (3)  Buffer
                  clientChannel.read(byteBuffer);
                  byteBuffer.flip();
                  System.out.println(
                      Charset.defaultCharset().newDecoder().decode(byteBuffer).toString());
                } finally {
                  keyIterator.remove();
                  key.interestOps(SelectionKey.OP_READ);
                }
              }

            }
          }
        }
      } catch (IOException ignored) {
      }
    }).start();

  }
}
```

 JDK  NIO 

- JDK  NIO  epoll  bug  cpu  100%
-  NIO  bug bug

Netty  JDK  NIO 

### 3. AIO (Asynchronous I/O)

AIO  NIO 2 Java 7  NIO  NIO 2,IO IO 

AIO IO NIO  NIO  IO  NIO  IO  IO IO AIO  IO IO[LinuxIO](https://mp.weixin.qq.com/s?__biz=Mzg3MjA4MTExMw==&mid=2247484746&idx=1&sn=c0a7f9129d780786cabfcac0a8aa6bb7&source=41#wechat_redirect) 

 AIO Netty  AIO

## 

- Netty 
- https://zhuanlan.zhihu.com/p/23488863 ()