Multi-threading in Java

Multi-threading in java is a process of executing multiple threads simultaneously.However, we use multi-threading than multiprocessing because threads use a shared memory area. They don't allocate separate memory area so saves memory, and context-switching between the threads takes less time than process.

Java Multi-threading is mostly used in games, animation, etc.

Advantages of Java Multi-threading

1) It doesn't block the user because threads are independent and you can perform multiple operations at the same time.

2) Yo can perform many operations together, so it saves time.

3) Threads are independent, so it doesn't affect other threads if an exception occurs in a single thread.

Multi-threading can be achieved in two ways:

1. Extending the Thread class

2. Implementing the Runnable Interface

Thread creation by extending the Thread class

We create a class that extends the java.lang.Thread class. This class overrides the run() method available in the Thread class. A thread begins its life inside run() method. We create an object of our new class and call start() method to start the execution of a thread. Start() invokes the run() method on the Thread object.

Thread creation by implementing the Runnable Interface

We create a new class which implements java.lang.Runnable interface and override run() method. Then we instantiate a Thread object and call start() method on this object.