线程的状态:一个线程只能有一次NEW状态,和TERMINATED状态
NEW(新建状态):创建后,启动前。线程就处于该状态
public class Test01 {
public static void main(String[] args) {
Thread t = new Thread();
State s = t.getState();
System.out.println(s);
}
}
RUNNABLE(可运行状态):线程正在执行代码,就处于该状态。
public class Test02 {
public static void main(String[] args) throws InterruptedException {
Runnable r = new Runnable() {
@Override
public void run() {
for(;;);
}
};
Thread t = new Thread(r);
t.start();
Thread.sleep(100);//保证线程已经启动,并开始执行run方法中的代码
State s = t.getState();
System.out.println(s);
}
}
BLOCKED(阻塞状态):一个线程获取synchronized锁对象失败,就处于该状态
public class Test03 {
public static void main(String[] args) throws InterruptedException {
Runnable r = new Runnable() {
@Override
public void run() {
System.out.println(Thread.currentThread().getName());
}
};
Thread t = new Thread(r);
t.start();
Thread.sleep(1000);//保证线程已经启动,并把run方法中的代码执行完毕
State s = t.getState();
System.out.println(s);
}
}
WAITING(无限等待):一个线程获取Lock锁对象失败,或者调用wait()方法,就处于该状态
public class Test04 {
public static void main(String[] args) throws InterruptedException {
Runnable r = new Runnable() {
@Override
public void run() {
try {
Thread.sleep(50000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
};
Thread t = new Thread(r);
t.start();
Thread.sleep(100);//保证线程已经启动,并开始执行run方法中的代码
State s = t.getState();
System.out.println(s);
}
}
TIMED_WAITING(计时等待状态):线程正执行sleep方法或者wait(long Mills)就处于该状态
public class Test05 {
public static void main(String[] args) throws InterruptedException {
Runnable r = new Runnable() {
@Override
public void run() {
synchronized(this) {
for(;;);
}
}
};
Thread t1 = new Thread(r);
Thread t2 = new Thread(r);
t1.start();
t2.start();
Thread.sleep(100);//保证两个线程都已经启动,并开始执行run方法
System.out.println(t1.getState());
System.out.println(t2.getState());
}
}
TERMINATED(消亡状态):线程把任务执行完毕后,就处于该状态。