Thread.State

• NEW
  A thread that has not yet started is in this state.
• RUNNABLE
  A thread executing in the Java virtual machine is in this state.
• BLOCKED
  A thread that is blocked waiting for a monitor lock is in this state.   请求获得锁
• WAITING
  A thread that is waiting indefinitely for another thread to perform a particular action is in this state.    等待别的线程的响应      

• • Object.wait with no timeout
  • Thread.join with no timeout
  • LockSupport.park

• 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.

• • Thread.sleep
  • Object.wait with timeout
  • Thread.join with timeout
  • LockSupport.parkNanos
  • LockSupport.parkUntil

• TERMINATED
  A thread that has exited is in this state.   线程结束

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.

可以通过thread.getState()查看线程所处的状态