1.继承Thread类:创建一个类,继承自 Thread 类,并重写 run() 方法来定义线程的执行逻辑。然后可以实例化这个类并调用 start() 方法来启动线程。
public class MyThread extends Thread {
@Override
public void run() {
// 线程执行逻辑
for (int i = 0; i < 5; i++) {
System.out.println("当前线程: " + Thread.currentThread().getName() + ",i = " + i);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
public static void main(String[] args) {
MyThread thread = new MyThread();
thread.start();
}
}
2.实现Runnable接口:创建一个类,实现 Runnable 接口,并实现 run() 方法来定义线程的执行逻辑。然后可以将这个类的实例传递给 Thread 类的构造函数来创建线程。
public class MyRunnable implements Runnable {
@Override
public void run() {
// 线程执行逻辑
for (int i = 0; i < 5; i++) {
System.out.println("当前线程: " + Thread.currentThread().getName() + ",i = " + i);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
public class Main {
public static void main(String[] args) {
MyRunnable myRunnable = new MyRunnable();
Thread thread = new Thread(myRunnable);
thread.start();
}
}
3.实现Callable接口:它可以让线程执行完后返回一个结果或者抛出一个异常。与 Runnable 接口不同的是,Callable 接口中的 call() 方法可以声明抛出异常,并且可以有返回值。
import java.util.concurrent.Callable;
public class MyCallable implements Callable<Integer> {
@Override
public Integer call() throws Exception {
int sum = 0;
for (int i = 1; i <= 100; i++) {
sum += i;
}
return sum;
}
}
public class Main {
public static void main(String[] args) throws Exception {
Callable<Integer> myCallable = new MyCallable();
FutureTask<Integer> futureTask = new FutureTask<>(myCallable);
Thread thread = new Thread(futureTask);
thread.start();
System.out.println("计算结果:" + futureTask.get());
}
}
4.使用线程池的方式创建线程:使用线程池可以更好地管理和复用线程资源,从而提高程序的性能和效率。Java 提供了 Executor 框架来创建和管理线程池。
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
public class Main {
public static void main(String[] args) {
// 创建线程池,指定线程数为 5
ExecutorService executor = Executors.newFixedThreadPool(5);
// 提交任务给线程池
for (int i = 0; i < 10; i++) {
Runnable worker = new WorkerThread("任务 " + (i + 1));
executor.execute(worker);
}
// 关闭线程池
executor.shutdown();
}
}
class WorkerThread implements Runnable {
private String taskName;
public WorkerThread(String taskName) {
this.taskName = taskName;
}
@Override
public void run() {
System.out.println(Thread.currentThread().getName() + " 开始执行任务:" + taskName);
try {
// 模拟任务执行时间
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println(Thread.currentThread().getName() + " 完成任务:" + taskName);
}
}