Java创建多线程的8种方式集合

//方式1
package cn.itcats.thread.Test1; 
public class Demo1 extends Thread{
 
    //重写的是父类Thread的run()
 public void run() {
  System.out.println(getName()+"is running...");
 }  
 public static void main(String[] args) {
  Demo1 demo1 = new Demo1();
  Demo1 demo2 = new Demo1();
  demo1.start();
  demo2.start();
 }
}

//Thread类源码中的run()方法
//target为Thread 成员变量中的 private Runnable target;
 
 @Override
    public void run() {
        if (target != null) {
            target.run();
        }
    }

package cn.itcats.thread.Test1; 
/**
 * 第二种创建启动线程的方式
 * 实现Runnale接口
 * @author fatah
 */
public class Demo2 implements Runnable{
 
    //重写的是Runnable接口的run()
 public void run() {
   System.out.println("implements Runnable is running");
 } 
 public static void main(String[] args) {
  Thread thread1 = new Thread(new Demo2());
  Thread thread2 = new Thread(new Demo2());
  thread1.start();
  thread2.start();
 } 
}

package cn.itcats.thread.Test1;
/**
 * 创建启动线程的第三种方式————匿名内部类
 * @author fatah
 */
public class Demo3 {
 public static void main(String[] args) {
  //方式1：相当于继承了Thread类，作为子类重写run()实现
  new Thread() {
   public void run() {
    System.out.println("匿名内部类创建线程方式1...");
   };
  }.start();  
    
  //方式2:实现Runnable,Runnable作为匿名内部类
  new Thread(new Runnable() {
   public void run() {
    System.out.println("匿名内部类创建线程方式2...");
   }
  } ).start();
 }
}

package cn.itcats.thread.Test1; 
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.FutureTask;
import java.util.concurrent.RunnableFuture;
 
/**
 * 方式4:实现Callable<T> 接口
 * 含返回值且可抛出异常的线程创建启动方式
 * @author fatah
 */
public class Demo5 implements Callable<String>{ 
 public String call() throws Exception {
  System.out.println("正在执行新建线程任务");
  Thread.sleep(2000);
  return "新建线程睡了2s后返回执行结果";
 }
 
 public static void main(String[] args) throws InterruptedException, ExecutionException {
  Demo5 d = new Demo5();
  /* call()只是线程任务,对线程任务进行封装
   class FutureTask<V> implements RunnableFuture<V>
   interface RunnableFuture<V> extends Runnable, Future<V>
  */
  FutureTask<String> task = new FutureTask<>(d);
  Thread t = new Thread(task);
  t.start();
  System.out.println("提前完成任务...");
  //获取任务执行后返回的结果
  String result = task.get();
  System.out.println("线程执行结果为"+result);
 } 
}

package cn.itcats.thread.Test1; 
import java.util.Timer;
import java.util.TimerTask;
 
/**
 * 方法5：创建启动线程之Timer定时任务
 * @author fatah
 */
public class Demo6 {
	public static void main(String[] args) {
		Timer timer = new Timer();
		timer.schedule(new TimerTask() {
			@Override
			public void run() {
				System.out.println("定时任务延迟0(即立刻执行),每隔1000ms执行一次");
			}
		}, 0, 1000);
	}	
}

package cn.itcats.thread.Test1; 
import java.util.concurrent.Executor;
import java.util.concurrent.Executors; 
public class Demo7 {
 public static void main(String[] args) {
  //创建带有5个线程的线程池
  //返回的实际上是ExecutorService,而ExecutorService是Executor的子接口
  Executor threadPool = Executors.newFixedThreadPool(5);
  for(int i = 0 ;i < 10 ; i++) {
   threadPool.execute(new Runnable() {
    public void run() {
     System.out.println(Thread.currentThread().getName()+" is running");
    }
   });
  }  
 }
}

Executor threadPool = Executors.newFixedThreadPool(10);    

ExecutorService threadPool = Executors.newFixedThreadPool(10);   

package cn.itcats.thread.Test1; 
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
 
/**
 * 使用Lambda表达式并行计算
 * parallelStream
 * @author fatah
 */
public class Demo8 {
 public static void main(String[] args) {
  List<Integer> list = Arrays.asList(1,2,3,4,5,6);
  Demo8 demo = new Demo8();
  int result = demo.add(list);
  System.out.println("计算后的结果为"+result);
 }
 
 public int add(List<Integer> list) {
  //若Lambda是串行执行,则应顺序打印
  list.parallelStream().forEach(System.out :: println);
  //Lambda有stream和parallelSteam(并行)
  return list.parallelStream().mapToInt(i -> i).sum();
 }
}

package cn.itcats.thread; 
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableAsync;
 
@Configuration
@ComponentScan("cn.itcats.thread")
@EnableAsync
public class Config {
 
}

package cn.itcats.thread; 
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;
 
@Service
public class AsyncService {
 
 @Async
 public void Async_A() {
  System.out.println("Async_A is running");
 }
 
 @Async
 public void Async_B() {
  System.out.println("Async_B is running");
 }
}

package cn.itcats.thread; 
import org.springframework.context.annotation.AnnotationConfigApplicationContext; 
public class Run {
 public static void main(String[] args) {
  //构造方法传递Java配置类Config.class
  AnnotationConfigApplicationContext ac = new AnnotationConfigApplicationContext(Config.class);
  AsyncService bean = ac.getBean(AsyncService.class);
  bean.Async_A();
  bean.Async_B();
 }
}