java线程

线程的实现:

1.继承Thread 类，重写run函数

package demo2;

public class Demo1 {
    public static void main(String[] args) {
        Cat cat = new Cat();
        cat.start();
    }

}

class Cat extends Thread {
    int times = 0;

    // 重写run函数
    public void run() {
        while (true) {
            // 每一秒打印一次
            try {
                Thread.sleep(100);
            } catch (Exception e) {
                // TODO: handle exception
            }
            System.out.println("hello,world");
            times++;
            if (times == 10)
                break;
        }
    }
}

2.实现Runable接口，重写run函数 

package demo2;

public class Demo1 {
    public static void main(String[] args) {
        Cat cat = new Cat();
        Thread t = new Thread(cat);
        t.start();
    }

}

class Cat implements Runnable {

    int times = 0;

    // 重写run函数
    public void run() {
        while (true) {
            // 每一秒打印一次
            try {
                Thread.sleep(100);
            } catch (Exception e) {
                // TODO: handle exception
            }
            System.out.println("hello,world");
            times++;
            if (times == 10)
                break;
        }
    }
}

3.多线程运作

package demo2;

public class Demo2 {
    public static void main(String[] args) {
        Pig pig = new Pig(10);
        Bird bird = new Bird(10);
        Thread t1 = new Thread(pig);
        Thread t2 = new Thread(bird);
        t1.start();
        t2.start();
    }
}

class Bird implements Runnable {
    int n, ret = 0, times = 0;

    public Bird(int times) {
        this.times = times;
    }

    @Override
    public void run() {
        // TODO Auto-generated method stub
        while (true) {
            try {
                Thread.sleep(1000);
            } catch (Exception e) {
                // TODO: handle exception
            }
            System.out.println("飞出来一只鸟");
            ret++;
            if (times == ret)
                break;
        }
    }
}

class Pig implements Runnable {
    int n, ret = 0, times = 0;

    public Pig(int times) {
        this.times = times;
    }

    @Override
    public void run() {
        // TODO Auto-generated method stub
        while (true) {
            try {
                Thread.sleep(100);
            } catch (Exception e) {
                // TODO: handle exception
            }
            System.out.println("飞出来一只猫");
            ret++;
            if (times == ret)
                break;
        }
    }
}

深入理解:

单线程运行

package demo2;
//import java.awt.Event;
public class Demo1{
    
    public static void main(String[] args) {
        Ticket t=new Ticket();
        Thread p=new Thread(t);
        p.start();
    }
    
}


class Ticket implements Runnable{
    int num=1000;

    public int getNum() {
        return num;
    }

    public void setNum(int num) {
        this.num = num;
    }

    @Override
    public void run() {
        // TODO Auto-generated method stub
        while(true){
            try {
                Thread.sleep(100);
            } catch (Exception e) {
                // TODO: handle exception
            }
            num--;
            System.out.println("还剩下"+num);
        }
    }
    
    
}

多线性运行：

package demo2;

//import java.awt.Event;
public class Demo1 {

    public static void main(String[] args) {
        Ticket t = new Ticket();
        Ticket t1 = new Ticket();
        Ticket t2 = new Ticket();
        Thread p = new Thread(t);
        Thread p1 = new Thread(t1);
        Thread p2 = new Thread(t2);
        p.start();
        p1.start();
        p2.start();

    }

}

class Ticket implements Runnable {
    int num = 1000;

    public int getNum() {
        return num;
    }

    public void setNum(int num) {
        this.num = num;
    }

    @Override
    public void run() {
        // TODO Auto-generated method stub
        while (true) {
            try {
                Thread.sleep(100);
            } catch (Exception e) {
                // TODO: handle exception
            }
            num--;
            System.out.println("还剩下" + num);
        }
    }

}

加上synchronized (this)  解决同步问题：

synchronized (objiect)  其中object可以任意取，保证原子性

（加锁）

package demo2;

//import java.awt.Event;
public class Demo1 {

    public static void main(String[] args) {
        Ticket t = new Ticket();
        Thread p = new Thread(t);
        Thread p1 = new Thread(t);
        Thread p2 = new Thread(t);
        p.start();
        p1.start();
        p2.start();

    }

}

class Ticket implements Runnable {
    int num = 1000;

    public int getNum() {
        return num;
    }

    public void setNum(int num) {
        this.num = num;
    }

    @Override
    public void run() {
        // TODO Auto-generated method stub
        while (true) {
            synchronized (this) {
                if (num > 0) {

                    try {
                        Thread.sleep(100);
                    } catch (Exception e) {
                        // TODO: handle exception
                    }
                    num--;
                    System.out.println("还剩下" + num);
                } else {
                    break;
                }
            }
        }
    }

}