java项目中多线程使用场景与实现方式详解

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
 
 
public class NetworkTask implements Runnable {
    private String urlStr;
 
 
    public NetworkTask(String urlStr) {
        this.urlStr = urlStr;
    }
 
 
    @Override
    public void run() {
        try {
            URL url = new URL(urlStr);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("GET");
            BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            String inputLine;
            StringBuilder content = new StringBuilder();
            while ((inputLine = in.readLine()) != null) {
                content.append(inputLine);
            }
            in.close();
            System.out.println(content.toString());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
 
 
    public static void main(String[] args) {
        Thread thread1 = new Thread(new NetworkTask("http://example.com"));
        Thread thread2 = new Thread(new NetworkTask("http://example.org"));
        thread1.start();
        thread2.start();
    }
}

 
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
 
 
public class ParallelProcessing {
    public static void main(String[] args) {
        int numTasks = 10;
        ExecutorService executor = Executors.newFixedThreadPool(4); // 创建一个固定大小的线程池
 
 
        for (int i = 0; i < numTasks; i++) {
            int taskId = i;
            executor.submit(() -> {
                System.out.println("Processing task " + taskId + " by " + Thread.currentThread().getName());
                // 模拟任务处理时间
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            });
        }
 
 
        executor.shutdown(); // 关闭线程池
    }
}

public class BackgroundTask implements Runnable {
    @Override
    public void run() {
        System.out.println("Background task started by " + Thread.currentThread().getName());
        // 模拟长时间运行的任务
        try {
            Thread.sleep(5000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("Background task completed by " + Thread.currentThread().getName());
    }
 
 
    public static void main(String[] args) {
        Thread backgroundThread = new Thread(new BackgroundTask());
        backgroundThread.start();
    }
}

public class RealTimeTask implements Runnable {
    private String sensorName;
 
 
    public RealTimeTask(String sensorName) {
        this.sensorName = sensorName;
    }
 
 
    @Override
    public void run() {
        System.out.println("Monitoring sensor: " + sensorName);
        // 模拟传感器监控逻辑
        try {
            Thread.sleep(2000); // 模拟传感器读取延迟
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("Sensor " + sensorName + " data processed");
    }
 
 
    public static void main(String[] args) {
        Thread sensor1 = new Thread(new RealTimeTask("Sensor1"));
        Thread sensor2 = new Thread(new RealTimeTask("Sensor2"));
        sensor1.start();
        sensor2.start();
    }
}

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
 
 
public class UIWithMultithreading extends JFrame {
    private JButton button;
    private JLabel label;
 
 
    public UIWithMultithreading() {
        button = new JButton("Start Task");
        label = new JLabel("Status: Idle");
        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                startLongRunningTask();
            }
        });
        setLayout(new FlowLayout());
        add(button);
        add(label);
        setSize(300, 200);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }
 
 
    private void startLongRunningTask() {
        label.setText("Status: Working...");
        new Thread(() -> {
            // 模拟长时间运行的任务
            try {
                Thread.sleep(5000); // 模拟任务处理时间
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            SwingUtilities.invokeLater(() -> label.setText("Status: Completed"));
        }).start();
    }
 
 
    public static void main(String[] args) {
        new UIWithMultithreading();
    }
}