Java has built-in support for multithreaded programming. A multithreaded program contains two or more parts that can run at the same time. Each part of such a program is called a thread, and each thread defines a separate path of execution.

Main Thread

When the Java program starts, the thread starts working immediately. This is usually referred to as the main thread of our program because it is executed when our program starts.

Properties :

• This is the thread from which other "child" threads are generated.
• This often has to be the last thread to complete execution as it requires various shutdown actions

How to control the Main thread

The main thread is created automatically when our program starts. To control it, we need to get a link to it. This can be done by calling the currentThread() method, which is in the Thread class. This method returns a reference to the called thread. The default priority of the main thread is 5 and for all other user threads, the priority is inherited from the child-parent.

In Java, the main thread is the first thread that is created when a Java program starts executing. It is the thread that executes the main method of the program, which is the entry point of the program. The main thread is responsible for creating and managing other threads in the program.

Controlling the main thread in Java involves two main aspects: controlling its behavior and synchronizing it with other threads.

To control the behavior of the main thread, you can use various methods provided by the Thread class. For example, you can use the sleep method to make the main thread pause for a specified amount of time. You can also use the join method to make the main thread wait for other threads to complete their execution.

To synchronize the main thread with other threads, you can use various synchronization mechanisms such as locks, semaphores, and monitors. These mechanisms allow you to coordinate the execution of multiple threads and ensure that they do not interfere with each other's execution.

In addition to these methods, you can also use various tools provided by the Java platform to monitor and control the behavior of the main thread and other threads in your program. These tools include the Java Virtual Machine Profiler Interface (JVMPI), the Java Management Extensions (JMX), and the Java Debug Interface (JDI). These tools provide powerful features for debugging, profiling, and monitoring the performance of your Java programs.