线程基础

实现过程

1. 自己描述一个类
2. 继承父类Thread
3. 重写run方法
4. new一个线程对象，调用start方法，让线程进入就绪状态 ```java package test;

public class Person extends Thread { private String n;

public Person(String name) {
    this.n = name;
}
public void run() {
    for (int i = 0; i < 100; i++) {
        System.out.println(this.n + "跑了" + i + "米");
    }
}
    public static void main(String[] args) {
        Person perons1 = new Person("a");
        Person perons2 = new Person("b");
        Person perons3 = new Person("c");
        perons1.start();
        perons2.start();
        perons3.start();
}

}

第二种线程对象的写法<br />使用实现
```java
package test;
public class Person implements Runnable {
    private String n;
    public Person(String name) {
        this.n = name;
    }
    public void run() {
        for (int i = 0; i < 100; i++) {
            System.out.println(this.n + "跑了" + i + "米");
        }
    }
    public static void main(String[] args) {
            Person perons1 = new Person("a");
            Person perons2 = new Person("b");
            Person perons3 = new Person("c");
            new Thread(perons1).start();
            new Thread(perons2).start();
            new Thread(perons3).start();
    }
}

synchronized

锁定的是对象

public class Test{
    public synchronized void get() { // 可以写在这里
    }
    public void get() { 
        int a = 1;
        synchronized(对象){ // 可以写在这里
        }
    }
}

wait

锁定的是线程

public class Test {
       public void get(){
        this.wait();
    }
}
加入有个Test1类对象调用了Test的get方法，锁定的是Test1的线程

notify/notifyAll 唤醒线程

join

合并线程——可以传参数

package test;
public class Person extends Thread {
    private String n;
    public Person(String name) {
        this.n = name;
    }
    public void run() {
        Pig p = new Pig();
        try {
            p.join(); // Pig线程加入Person线程
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

Timer

有计时器的功能