Java Interview Questions-4

Question: How to create multithread in a program?
Answer: You have two ways to do so. First, making your class "extends" Thread class. Second, making your class "implements" Run able interface. Put jobs in a run() method and call start() method to start the thread.

Question: Can Java object be locked down for exclusive use by a given thread?
Answer: Yes. You can lock an object by putting it in a "synchronized" block. The locked object is inaccessible to any thread other than the one that explicitly claimed it

Question: Can each Java object keep track of all the threads that want to exclusively access to it?
Answer: Yes

Question: What state does a thread enter when it terminates its processing?
Answer: When a thread terminates its processing, it enters the dead state.

Question: What invokes a thread's run() method?
Answer: After a thread is started, via its start() method of the Thread class, the JVM invokes the thread's run() method when the thread is initially executed.

Question: What is the purpose of the wait(), notify(), and notifyAll() methods?
Answer: The wait(),notify(), and notifyAll() methods are used to provide an efficient way for threads to communicate each other.

Question: What are the high-level thread states?
Answer: The high-level thread states are ready, running, waiting, and dead.

Question: What is the Collections API?
Answer: The Collections API is a set of classes and interfaces that support operations on collections of objects.

Question: What is the List interface?
Answer: The List interface provides support for ordered collections of objects.

Question: How does Java handle integer overflows and underflows?
Answer: It uses those low order bytes of the result that can fit into the size of the type allowed by the operation.