Answer: Yes, we can override start() method of thread in Java, the same way we override any other methods. for example, In below, custom thread class MyThread, both start() method and run() method have been overridden.
Can we override the run method?
We can override start/run method of Thread class because it is not final. But it is not recommended to override start() method, otherwise it ruins multi-threading concept.
Can we overload run () method of thread?
Overloading of Thread class run() method
Overloading of run() method is possible. … The other overloaded method we have to call explicitly like a normal method call.
Can you override the thread start () method?
Yes, we can override the start() method of a Thread class in Java. We must call the super. … If we call the run() method directly from within our start() method, it can be executed in the actual thread as a normal method, not in a new thread.
Can we call run () method of a thread class?
No, you can not directly call run method to start a thread. You need to call start method to create a new thread. If you call run method directly , it won’t create a new thread and it will be in same stack as main.
Why must you override the run () method in your thread class?
It is highly recommended to override run() method because it improves the performance of the system. If we don’t override Thread class run() method in our defined thread then Thread class run() method will be executed and we will not get any output because Thread class run() is with an empty implementation.
Can we have multiple run method in Java?
You can’t have two run() methods, because you (and the compiler) could not know which one to execute when calling obj. run() . By using inner class you can achieve multiple run methods in a single class.
What happens if you don’t override the thread class run () method?
Answer: If we don’t override run() method, compiler will not flash any error and it will execute run() method of Thread class that has empty implemented, So, there will be no output for this thread.
Can we start a thread twice?
No. After starting a thread, it can never be started again. If you does so, an IllegalThreadStateException is thrown. In such case, thread will run once but for second time, it will throw exception.
Is run method is abstract in thread class?
run() is not abstract, as users need to override it, and why Thread.
Which method must be override by Java thread class?
While creating a thread class we must override the run() method of the Thread class. This method provides an entry point for the thread and you will put your complete business logic inside this method.
Can we override static method in Java?
Can we Override static methods in java? We can declare static methods with the same signature in the subclass, but it is not considered overriding as there won’t be any run-time polymorphism. Hence the answer is ‘No’.
What happens if we don’t override a run method 1 point newly created thread won’t be called newly created thread will be called?
When we call start() method on thread, it internally calls run() method with newly created thread. So, if we don’t override run() method newly created thread won’t be called and nothing will happen. main has started. main has ended.
What happens if we directly call run method of thread?
The run method is just another method. If you call it directly, then it will execute not in another thread, but in the current thread. If start isn’t called, then the Thread created will never run. The main thread will finish and the Thread will be garbage collected.
Why we use OBJ start instead of obj run?
So what is the difference between the start and run method? Main difference is that when program calls start() method a new Thread is created and code inside run() method is executed in new Thread while if you call run() method directly no new Thread is created and code inside run() will execute on current Thread.
What if we call Java run () method directly instead start () method?
If run() method is called directly instead of start() method in Java code, run() method will be treated as a normal overridden method of the thread class (or runnable interface). This run method will be executed with in the context of the current thread not in a new thread.