Why java does not support destructor?

Answer 1

AMIT KUMAR

• 3th Nov , 2014

Java does not support destructors, since java supports the concept of garbage collection,hence the garbage collector is used to automatically free the space which has occupied by the program while running.Garbage collector calls the finalize() method which is defined in the object class. finalize() method is called once for each object.

Answer 2

The finalize() method in Java is the closest mechanism to the concept of a destructor. But since the garbage collector is not guaranteed to run at any specific time depending on finalize() to cleanup resources is not best practice.

The finalize() method in java objects is called by the garbage collector on an object when garbage collection determines that there are no more references to the object.

Best practice in Java is to close resources and release references to them when they are no longer needed so the garbage collector can reclaim memory. So for example, InputStreams have a close() method which should be called in a finally block to ensure the streams are closed.

Java 1.7 introduced the try-with-resources statement that declares one or more resources and closes the resource after the statement block is executed even if an exception occurs. This a destructor-like mechanism but must be explicitly called in the program.

Answer 3

The purpose of a Destructor is usually to clear off unused variables and clean up the memory. Java has in built memory handling mechanisms (Garbage collection) that clear off unused memory automatically. Hence there is no requirement for destructor methods.

Tip: In spite of automatic garbage collection by java, it is a good practice to nullify all unused objects in the finally block of the code.