The difference between synchronized and lock locks

1、synchronized yes java keyword ,jvm level ; lock It's a class ;

2、synchronized Unable to get lock status , lock You can get the state of the lock ;

3、synchronized It's an automatic lock , If the code is executed or an exception occurs , He will automatically release the locked resources , lock Manual lock , It needs to be called manually unlock Method to release locked resources , It's usually in finally; If it is not released, a deadlock will occur ;

4、synchronized If the thread a Get the resources of the lock , happening , Threads b Will be waiting , and lock If the locked resource cannot be obtained , The thread ends without waiting ;

5、synchronized It's reentrant 、 Non interruptible , Unfair , lock Reentrant 、 To judge 、 Fair enough （ Both are acceptable ）;