Java多线程与并发库高级应用 学习笔记 1-9课

来源XXX，免得打广告嫌疑。

http://www.cnblogs.com/whgw/archive/2011/10/03/2198506.html 

今天看了文章才发现创建线程最佳方式为实现Runnable接口，之前的习惯要改鲁。

http://blog.csdn.net/imzoer/article/details/8500670

Java中Timer的用法

package timer;

import java.util.Calendar;
import java.util.Timer;
import java.util.TimerTask;

public class TimerTest {
    static Timer timer = new Timer();

    public static void main(String[] args) {

        // task task to be scheduled.
        // delay delay in milliseconds before task is to be executed.
        // period time in milliseconds between successive task executions.
        timer.schedule(new MyTimerTask(), 2000);
    }

}
/*
 * 执行间隔2秒与4秒交替进行
 */
class MyTimerTask extends TimerTask {
    static boolean change = true;
    Calendar calendar = Calendar.getInstance();

    @Override
    public void run() {
        change = !change;
        System.out.println(calendar.getTime());
        new Timer().schedule(new MyTimerTask(), change ? 2000 : 4000);
    }

}

线程安全的在于多线程对同一资源对象的读、写、事务完成阶段。

http://www.cnblogs.com/mengdd/archive/2013/02/16/2913806.html

java synchronized关键字详解 

弄明白synchronized这个关键字在不同情况锁住的对象粒度，以及范围。

package Thread;

/**
 * 子线程2次，主线程4次交替循环10次。
 *
 */
public class AlternateLoop {
    static Sysout sysout = new Sysout();

    public static void main(String[] args) {
        for (int i = 0; i < 10; i++) {
            sysout.subBusiness(i);
            sysout.mainBusiness(i);
        }
    }

}

// class MyThread implements Runnable {
// @Override
// public void run() {
// AlternateLoop.sysout.subBusiness(1);
// }
// }
//
// class MyThread2 implements Runnable {
//
// @Override
// public void run() {
// AlternateLoop.sysout.mainBusiness(i);
// }
// }

/*
 * 同一资源管理业务逻辑
 */
class Sysout {
    private boolean isSub = true;

    public synchronized void mainBusiness(int i) {
        while (isSub) {
            try {
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        for (int j = 0; j < 4; j++) {
            System.out.println("mainBusiness" +j+"loop of"+ i);
        }
        isSub = true;
        this.notify();
    }

    public synchronized void subBusiness(int i) {
        while (!isSub) {
            try {
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        for (int j = 0; j < 2; j++) {
            System.out.println("subBusiness" +j+"loop of"+ i);
        }

        isSub = false;
        this.notify();
    }
}

Java并发编程：深入剖析ThreadLocal 

每个线程存在对应的线程副本对象。

package Thread;

import java.util.Random;


public class ThreadLocalTest {

    public static ThreadLocal<Integer> threadLocal = new ThreadLocal<Integer>();

    public static void main(String[] args) {
        for (int i = 0; i < 2; i++) {
            new Thread(new Runnable() {
                @Override
                public void run() {
                    int data=new Random().nextInt();
                    System.out.println(Thread.currentThread().getName()+"has put data :"+data);
                    threadLocal.set(data);
                    new A().get();
                    new B().get();
                }
            }).start();
        }

    }
    static class A {
        public void get() {
            int data=threadLocal.get();
            System.out.println("A from Thread" + Thread.currentThread().getName() + ""
                        + data);
        }
    }
    
    static class B {
        public void get() {
            int data=threadLocal.get();
            System.out.println("B from Thread" + Thread.currentThread().getName() + ""
                        + data);
        }
    }
}

上面的例子需要改造一下 这种内部静态类用起来不科学啊。

java线程:Atomic(原子的)  jdk 1.5的新特性 

Java并发编程：线程池的使用

package Thread;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

public class ThreadPoolTest {

    public static void main(String[] args) {
        ExecutorService threadPool =Executors.newCachedThreadPool();
//        ExecutorService threadPool =Executors.newFixedThreadPool(10);
//        ExecutorService threadPool = Executors.newSingleThreadExecutor();

        for (int i = 0; i < 10; i++) {
            final int task = 1;
            threadPool.execute(new Runnable() {

                @Override
                public void run() {
                    for (int j = 0; j < 10; j++) {
                        try {
                            Thread.sleep(200);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                        System.out.println(Thread.currentThread().getName()
                                + "is looping of " + j + "for task of" + task);
                    }
                }
            });
        }

        Executors.newScheduledThreadPool(3).scheduleAtFixedRate(new Runnable() {
            @Override
            public void run() {
                System.out.println("bombing!");
            }
        }, 6, 2, TimeUnit.SECONDS);

    }
}