java中线程的实现方式

java中线程的实现方式

1. 继承Thread类

代码 ：

package ThreadImplamen;

import static java.lang.Thread.sleep;

public class threadImp {

  public static void main(String[] args) {
    Thread thread = new Imp1();
    thread.start();
    int i;
    for (i=0;i<5;i++){
      System.out.println("Main!");
      try {
        sleep(100);
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
    }
  }

}


class Imp1 extends Thread{

  @Override
  public void run() {
    int i;
    for (i=0;i<5;i++){
      System.out.println("继承 Thread类实现的线程！");
      try {
        sleep(100);
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
    }
  }
}

测试：

Main!
继承 Thread类实现的线程！
Main!
继承 Thread类实现的线程！
Main!
继承 Thread类实现的线程！
Main!
继承 Thread类实现的线程！
继承 Thread类实现的线程！
Main! 

2. 实现Runnable接口

代码：

package ThreadImplamen;

import static java.lang.Thread.sleep;

public class ThreadImpl2 {
  public static void main(String[] args) {
    Runnable run = new RunnableImp();
    Thread thread = new Thread(run);
    thread.start();
    int i;
    for (i=0;i<5;i++){
      System.out.println("Main!");
      try {
        sleep(100);
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
    }
  }


}
class  RunnableImp implements Runnable{

  @Override
  public void run() {
    int i;
    for (i=0;i<5;i++){
      System.out.println("实现Runnable接口实现的线程！");
      try {
        sleep(100);
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
    }
  }
}

测试：

实现Runnable接口实现的线程！
Main!
Main!
实现Runnable接口实现的线程！
实现Runnable接口实现的线程！
Main!
实现Runnable接口实现的线程！
Main!
Main!
实现Runnable接口实现的线程！

3. 实现Callable接口

此方法可接受返回结果

代码：

package ThreadImplamen;

import static java.lang.Thread.sleep;

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.FutureTask;
import javax.script.ScriptException;


public class ThreadImpl3 {

  public static void main(String[] args) throws ExecutionException, InterruptedException {

    Callable callable = new CallableImp();
    FutureTask futureTask = new FutureTask(callable);
    Thread thread = new Thread(futureTask);
    thread.start();
    int i;
    for (i = 0; i < 5; i++) {
      System.out.println("Main!");
      try {
        sleep(100);
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
    }

    System.out.println(futureTask.get());
  }
}

class CallableImp implements Callable {

  @Override
  public Object call() throws Exception{
      int i;
      for (i = 0; i < 5; i++) {
        System.out.println("实现Callable接口实现的线程！");
        try {
          sleep(100);
        } catch (InterruptedException e) {
          e.printStackTrace();
        }
      }
      return String.valueOf("这是 你要的返回值");
    }
  }

测试：

Main!
实现Callable接口实现的线程！
实现Callable接口实现的线程！
Main!
Main!
实现Callable接口实现的线程！
Main!
实现Callable接口实现的线程！
Main!
实现Callable接口实现的线程！
这是 你要的返回值

4. 线程池

代码：

package ThreadImplamen;

import static java.lang.Thread.sleep;

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.FutureTask;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

public class ThreadImpl4 {
  public static void main(String[] args) throws ExecutionException, InterruptedException {

    int pcount = Runtime.getRuntime().availableProcessors();
    //最大线程数控制
    int maxthreadNum = 5;
    ExecutorService executor = new ThreadPoolExecutor(pcount, maxthreadNum, 10, TimeUnit.SECONDS,
        new ArrayBlockingQueue<>(1000), Executors.defaultThreadFactory(), new ThreadPoolExecutor.CallerRunsPolicy());
    for (int i = 0; i < 2; i++) {
      executor.execute(new test1());
    }
    int i;
    for (i = 0; i < 5; i++) {
      System.out.println("Main!");
      try {
        sleep(100);
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
    }
  }

}

class test1 implements Runnable{

  @Override
  public void run() {
    int i;
    for (i = 0; i < 5; i++) {
      System.out.println("在线程池内！");
      try {
        sleep(100);
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
    }
  }
}

测试：

在线程池内！
在线程池内！
Main!
在线程池内！
在线程池内！
Main!
在线程池内！
在线程池内！
Main!
在线程池内！
在线程池内！
Main!
在线程池内！
Main!
在线程池内！