Home > Java > javaTutorial > How to use NIO technology to implement asynchronous processing in Java functions?

How to use NIO technology to implement asynchronous processing in Java functions?

WBOY
Release: 2024-05-04 21:27:02
Original
931 people have browsed it

Leverage NIO for asynchronous processing in Java functions: Set a selector to listen for events on the channel. Register the channel to be monitored with the selector. Poll the selector, waiting for events on the channel. Handle specific events that occur on the channel according to the event type (such as connection, read and write, etc.).

如何利用 NIO 技术在 Java 函数中实现异步处理?

How to use NIO technology to implement asynchronous processing in Java functions

Introduction

NIO (Non-Blocking I/O, non-blocking I/O) is an asynchronous I/O technology that allows Java programs to handle I/O operations without blocking the calling thread. This makes it a crucial technique for achieving high performance in highly concurrent applications.

The basic concept of NIO

The core concept of NIO is:

  • Selector: Listening Events on multiple channels (such as sockets).
  • Channel: Abstract I/O operations, such as reading and writing.
  • Buffer (Buffer): Stores data and is used to interact with the channel.

Using NIO in a Java function

To use NIO to implement asynchronous processing in a Java function, follow these steps:

1. Set the selector

1

Selector selector = Selector.open();

Copy after login

2. Register the channel

Register the channel to be monitored to the selector:

1

2

3

ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();

serverSocketChannel.configureBlocking(false);

serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);

Copy after login

3. Poll the selector

Use the select() method to poll the selector and wait for events on the channel:

1

2

3

4

5

6

7

8

9

10

11

while (true) {

  selector.select();

  Iterator<SelectionKey> keys = selector.selectedKeys().iterator();

 

  while (keys.hasNext()) {

    SelectionKey key = keys.next();

    keys.remove();

 

    // 处理事件

  }

}

Copy after login

4. Handle events

Handle events on the channel, such as accepting connections:

1

2

3

4

5

6

if (key.isAcceptable()) {

  ServerSocketChannel server = (ServerSocketChannel) key.channel();

  SocketChannel client = server.accept();

  client.configureBlocking(false);

  client.register(selector, SelectionKey.OP_READ | SelectionKey.OP_WRITE);

}

Copy after login

Practical case

The following is an implementation using NIO Simple Java function for asynchronous processing:

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

import java.io.IOException;

import java.net.ServerSocket;

import java.net.Socket;

import java.nio.ByteBuffer;

import java.nio.channels.ServerSocketChannel;

import java.nio.channels.SocketChannel;

 

public class AsyncServer {

 

  public static void main(String[] args) throws IOException {

    ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();

    ServerSocket serverSocket = serverSocketChannel.socket();

    serverSocketChannel.configureBlocking(false);

    serverSocket.bind(new InetSocketAddress(9876));

 

    while (true) {

      SocketChannel client = serverSocketChannel.accept();

      if (client != null) {

        client.configureBlocking(false);

 

        ByteBuffer buffer = ByteBuffer.allocate(1024);

        client.read(buffer);

        if (buffer.remaining() == 0) {

          buffer.flip();

          String message = new String(buffer.array(), 0, buffer.limit());

          System.out.println("Received: " + message);

          client.write(ByteBuffer.wrap(("Hello, " + message).getBytes()));

        }

      }

    }

  }

}

Copy after login

Run the function

To run the function, save it as a Java file and compile and run it using the following commands:

1

2

javac AsyncServer.java

java AsyncServer

Copy after login

This function will start an asynchronous server on port 9876. You can use Telnet or other network tools to connect to the server and send messages.

The above is the detailed content of How to use NIO technology to implement asynchronous processing in Java functions?. For more information, please follow other related articles on the PHP Chinese website!

Related labels:
source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template