一、在Thread的源码中有写出线程的六种状态：
1）NEW：新建状态
2）RUNNABLE：就绪状态
源码注释为：线程在JVM的状态为RUNNABLE就绪状态，但是需要等待操作系统资源。
解析：其实在操作系统内核创建线程的当前状态如果是Initialized，则调用sync -> wait()，如果线程状态被设置为RUNNABLE，则唤醒执行run()方法
3）BLOCKED：阻塞状态
在抢夺Synchronized锁失败之后会进入BLOCKED阻塞状态；
等待状态的线程在调用notify()和notifyAll()被唤醒的时候也会进入BLOCKED阻塞状态；
而在竞争中拿到monitor锁之后会进入RUNNABLE就绪状态。
4）WAITING：等待状态
在调用Object.wait()，Thread.join()，LockSupport.park()方法时，线程会进入WAITING等待状态。
5）TIMED_WAITING：计时等待状态
在调用Thread.sleep(time)，Object.wait(timeout)，Thread.join(timeout)，LockSupport.parkNanos(timeout)，LockSupport.parkUntil(timeout)方法，线程会进入TIMED_WAITING计时等待状态。
6）TERMINATED：终止状态
二、Thread.java中源码的State枚举
publicenum State{/**
* Thread state for a thread which has not yet started.
*/
NEW,/**
* Thread state for a runnable thread. A thread in the runnable
* state is executing in the Java virtual machine but it may
* be waiting for other resources from the operating system
* such as processor.
*/
RUNNABLE,/**
* Thread state for a thread blocked waiting for a monitor lock.
* A thread in the blocked state is waiting for a monitor lock
* to enter a synchronized block/method or
* reenter a synchronized block/method after calling
* {@link Object#wait() Object.wait}.
*/
BLOCKED,/**
* Thread state for a waiting thread.
* A thread is in the waiting state due to calling one of the
* following methods:
* <ul>
* <li>{@link Object#wait() Object.wait} with no timeout</li>
* <li>{@link #join() Thread.join} with no timeout</li>
* <li>{@link LockSupport#park() LockSupport.park}</li>
* </ul>
*
* <p>A thread in the waiting state is waiting for another thread to
* perform a particular action.
*
* For example, a thread that has called <tt>Object.wait()</tt>
* on an object is waiting for another thread to call
* <tt>Object.notify()</tt> or <tt>Object.notifyAll()</tt> on
* that object. A thread that has called <tt>Thread.join()</tt>
* is waiting for a specified thread to terminate.
*/
WAITING,/**
* Thread state for a waiting thread with a specified waiting time.
* A thread is in the timed waiting state due to calling one of
* the following methods with a specified positive waiting time:
* <ul>
* <li>{@link #sleep Thread.sleep}</li>
* <li>{@link Object#wait(long) Object.wait} with timeout</li>
* <li>{@link #join(long) Thread.join} with timeout</li>
* <li>{@link LockSupport#parkNanos LockSupport.parkNanos}</li>
* <li>{@link LockSupport#parkUntil LockSupport.parkUntil}</li>
* </ul>
*/
TIMED_WAITING,/**
* Thread state for a terminated thread.
* The thread has completed execution.
*/
TERMINATED;}