JAVA doc的说明：[https://docs.oracle.com/javase/7/docs/api/java/lang/Thread.State.html]
public static enum Thread.State
extends Enum<Thread.State>
A thread state. A thread can be in one of the following states:
[NEW]
A thread that has not yet started is in this state.(After new it but not start)
[RUNNABLE]
A thread executing in the Java virtual machine is in this state(After call start() function).
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.
【JVM似乎不像OS那样区分就绪与运行两个状态，JVM中runnable状态的线程，可能是就绪（等待调度获取CPU），也可能是运行的状态，
JVM统统划分为执行态。】
[BLOCKED]
A thread that is blocked waiting for a monitor lock is in this state.
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 Object.wait.
【线程在等待object锁（synchronized），或者在调用Object.wait()之后，挂起并释放了锁，在被notify后，等待重新获取锁(reenter)】
[WAITING]
A thread that is waiting indefinitely for another thread to perform a particular action is in this state.
【等待的状态与BLOCKED有点类似，BLOCKED是等待获取到锁，WAITING是等待另外一个线程指定操作唤醒，相同点是线程都被挂起，且都
不持有锁（不持有正在竞争的锁，或已经持有但释放的锁），不同点是线程进入WAITING状态，说明它已经进入了代码块。
Thread state for a waiting thread. A thread is in the waiting state due to calling one of the following methods:
Object.wait with no timeout
Thread.join with no timeout
LockSupport.park
A thread in the waiting state is waiting for another thread to perform a particular action. For example, a thread that has called Object.wait() on an object is waiting for another thread to call Object.notify() or Object.notifyAll() on that object. A thread that has called Thread.join() is waiting for a specified thread to terminate.
】
[TIMED_WAITING]
A thread that is waiting for another thread to perform an action for up to a specified waiting time is in this state.
【与WAITING相比，加入了超时的控制，包括sleep。与时间有关的线程挂起，进入此状态。
Thread.sleep
Object.wait with timeout
Thread.join with timeout
LockSupport.parkNanos
LockSupport.parkUntil
】
[TERMINATED]
A thread that has exited is in this state.
The thread has completed execution.
A thread can be in only one state at a given point in time. These states are virtual machine states which do not reflect any operating system thread states.【注意是JVM的线程状态，区别OS的线程状态】
<<LockSupport>>
public class LockSupport extends Object
【
lock以及其它同步类的线程阻塞原语。Basic thread blocking primitives for creating locks and other synchronization classes.
举个例子：
static void park()
Disables the current thread for thread scheduling purposes unless the permit is available.
】
<<参考资料>>
1、有个cnblog写的挺不错的：http://www.cnblogs.com/zhengyun_ustc/archive/2013/03/18/tda.html
