This will guarantee that finalize of the parent class will be called in all conditions except when JVM exits:. These methods put more effort that JVM call finalize method of all object which are eligible for garbage collection and whose finalize has not yet called. It's not guaranteed, but JVM tries its best. So far its seems we are suggesting not to use finalize method because of its non-guaranteed behavior but than what is alternative of releasing resource , performing cleanup because there is no destructor in Java.
Having a method like close or destroy make much sense for releasing resources held by classes. In fact, JDK library follows this. In fact its one of the best practices to call the close method from the finally block in java.
The only caveat with this approach is it's not automatic, the client has to do the cleanup and if client forgot to do the cleanup there are chances of resources getting leaked, which again suggests us that we could probably give another chance to finalize method. You will be pleased to know that Java 7 has added an automatic resource management feature that takes care of closing all resource opened inside try block automatically, leaving no chance of manual release and leakage.
In the last paragraph, I pointed out that there are certain cases where overriding finalize makes sense like an ultimate last attempt to clean up the resource. If a Java c lass is made to held resources like input-output devices, JDBC connection then you should override finalize and call its close method from finalizing.
It is just another last attempt to release the resource which most likely has been already released due to the client calling the close method. This technique is heavily used inside the Java Development library. Since there is no guarantee when finalize method will run you could effectively lock hundreds of file-descriptor of earlier opened files or sockets and there is a high chance that your application will run out of file-descriptor and not be able to open any new file.
It's best to use finalize as the last attempt to do cleanup but never use finalize as a first or only attempt. That's all on finalize method in Java. It's extremely rare to override Objects. It's not advised to override it but if you have to then first read and understand Effective Java, Item 7, "Avoid Finalizers", very carefully, and then don't do it. Share to Twitter Share to Facebook.
Labels: core java , core java interview question. March 11, at PM Anonymous said January 16, at AM Anonymous said April 19, at AM Haramohan Sahu said October 9, at AM Kumaran said RajKumar, even clone method is declared as protected. July 2, at AM Anonymous said What's difference between finalize method and System. October 3, at AM Shantinath Chaudhary said October 6, at PM javin paul said October 8, at PM Andy said October 12, at AM Lorenzo Gomez said Great Article, thanks!
March 18, at AM. Newer Post Older Post Home. Subscribe to: Post Comments Atom. Subscribe for Discounts and Updates Follow. Explanation: As we see in the above output, we finalize method output because of overriding the actual finalize method. Explanation: The above example clearly illustrates that the finalize method not always guarantee to execute.
Java finalizes method is used to collect the garbage collected object. This method is called just before the GC method is called. This method is not always guaranteed to execute. This is a guide to Finalize in Java.
Here we discuss an introduction to the Finalize in Java, how it works, and examples for better understanding. You can also go through our other related articles to learn more —.
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