Java之线程编程的4种方法实现案例讲解

1、继承Thread

public class T4 {
public static void main(String[] args) {
System.out.println(Thread.currentThread());
Thread t1 = new A1();
t1.start();
}
}
class A1 extends Thread{
@Override
public void run() {
for(int i=0;i<10;i++) {
System.out.println("Thread:"+Thread.currentThread().getName());
}
}
}

2、实现Runnable接口

public class T3 {
public static void main(String[] args) {
System.out.println("Thread:"+Thread.currentThread().getName());
Thread t1 = new Thread(new A2());
t1.start();
}

}
class A2 implements Runnable{
@Override
public void run() {
int res =0;
for(int i=0;i<10;i++) {
res+=i;
System.out.println("Thread:"+Thread.currentThread().getName());
}
}
}

3、使用Callable和Future接口创建线程

import java.util.concurrent.Callable;
import java.util.concurrent.FutureTask;

public class T2 {
public static void main(String[] args) throws Exception {
System.out.println("Test3:" + Thread.currentThread().getName());
Callable c = new A4();
FutureTask ft = new FutureTask(c);
Thread t1 = new Thread(ft);
t1.start();
Object res = ft.get();
System.out.println("结果:" + res);
}
}
class A4 implements Callable {
@Override
public Object call() throws Exception {
int res = 0;
for (int i = 0; i < 10; i++) {
res += i;
System.out.println("Thread:" + Thread.currentThread().getName());
}
return res;
}
}

4、使用线程池创建线程

享元模式
享元模式Flyweight Pattern主要用于减少创建对象的数量，以减少内存占用和提高性能。这种类型的设计模式属于 结构型模式，它提供了减少对象数量从而改善应用所需的对象结构的方式
优点：大大减少对象的创建，降低系统内存的使用，以提高程序的执行效率。
缺点：提高了系统的复杂度，需要分离出外部状态和内部状态，而且外部状态具有固有化的性质，不应该随着内部 状态的变化而变化，否则会造成系统的混乱。

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;

public class T1 {
public static void main(String[] args) throws Exception {
Future[] arr = new Future[5];
ExecutorService es = Executors.newFixedThreadPool(3);
for (int i = 0; i < 5; i++) {
arr[i] = es.submit(new A4());
}
for (Future f : arr) {
Object res = f.get();
System.out.println("结果为：" + res);
}
es.shutdown();
}
}

class A4 implements Callable {
@Override
public Object call() throws Exception {
int res = 0;
for (int i = 0; i < 10; i++) {
res += i;
System.out.println("Thread" + Thread.currentThread().getName());
}
return res;
}
}

来源：https://blog.csdn.net/qq_45874107/article/details/113754912