What does the finalize method do in java?

Answer 1

The "finalize" method is called when an object is removed from memory. If you need to do any cleanup (closing streams/files, displaying output, etc.) you can put it in an overridden finalize method.

Answer 2

I assume that you mean the finalize() object method, and not the 'finally' clause in a try/catch/finally construct.

The finalize() method is called by the garbage collector just before the object is disposed of and the memory reclaimed. It was initially intended as a way for the programmer to clean up external resources used by the object, like closing a database connection or an open file.

However, since Java makes no guarantees as to when finalize() is called, or even that it will be called at all during the lifetime of the program, use of finalize() was abandoned.

The current recommendation is that finalize() should never be used for anything.

Answer 3

The final keyword is used in several different contexts as a modifier meaning that what it modifies cannot be changed in some sense. final classes You will notice that a number of the classes in Java library are declared final, e.g. public final class String This means this class will not be subclassed, and informs the compiler that it can perform certain optimizations it otherwise could not. It also provides some benefit in regard to security and thread safety. The compiler will not let you subclass any class that is declared final. You probably won't want or need to declare your own classes final though. final methods You can also declare that methods are final. A method that is declared final cannot be overridden in a subclass. The syntax is simple, just put the keyword final after the access specifier and before the return type like this: public final String convertCurrency() final fields You may also declare fields to be final. This is not the same thing as declaring a method or class to be final. When a field is declared final, it is a constant which will not and cannot change. It can be set once (for instance when the object is constructed, but it cannot be changed after that.) Attempts to change it will generate either a compile-time error or an exception (depending on how sneaky the attempt is). Fields that are both final, static, and public are effectively named constants. For instance a physics program might define Physics.c, the speed of light as public class Physics { public static final double c = 2.998E8; }

Answer 4

Java provides you a mechanism to run some code just before your object is deleted by the garbage collector. This code is located in a method named finalize() that all classes inherit from class Object. On the surface this sounds like a great idea; maybe your object opened up some resources, and you'd like to close them before your object is deleted. The problem is that, as you may have gathered by now, you can't count on the garbage collector to ever delete an object. So, any code that you put into your class's overridden finalize() method is not guaranteed to run. The finalize() method for any given object might run, but you can't count on it, so don't put any essential code into your finalize() method. In fact, we recommend that in general you don't override finalize() at all.