Interview Questions.

Question 1. What Is Garbage Collection In Java?

Answer :

Garbage Collection is an automatic memory control function.
The manner of destroying unreferenced gadgets is called Garbage Collection.
Once object is unreferenced it's far taken into consideration as unused item, subsequently JVM mechanically destroys that object.
In java developers duty is most effective to developing items and unreferencing the ones gadgets after usage.
Question 2. How Jvm Can Destroy Unreferenced Object?

Answer :

JVM internally uses a daemon thread referred to as "garbage collector" to spoil all unreferenced items.
A daemon thread is a service thread. Garbage Collector thread is called daemon thread because it gives services to JVM to spoil unreferenced gadgets.
This thread is low priority thread. Since it's miles a low precedence thread we cannot guarantee this execution.
Adv Java Interview Questions
Question three. So Can You Guarantee Objects Destruction?

Answer :

No, we can't guarantee items destruction although it is unreferenced, because we can not assure rubbish collector execution.
So, we are able to confirm whether item is eligible for rubbish series or not.
Question 4. Can We Force Garbage Collector?

Answer :

No, we can't pressure garbage collector to spoil gadgets , but we can request it.

Adv Java Tutorial
Question 5. How Can We Request Jvm To Start Garbage Collection Process?

Answer :

We have a technique called gc() in gadget elegance as static method and also in Runtime class as non static technique to request JVM to start garbage collector execution.
System.Gc();
Runtime.GetRuntime().Gc();
J2EE Interview Questions
Question 6. What Is The Algorithm Jvm Internally Uses For Destroying Objects?

Answer :

"mark and swap" is the algorithm JVM internally makes use of.

Question 7. Which Part Of The Memory Is Involved In Garbage Collection?

Answer :

Heap.

J2EE Tutorial Core Java Interview Questions
Question eight. What Is Responsibility Of Garbage Collector?

Answer :

Garbage Collector frees the reminiscence occupied by way of the unreachable items at some point of the java software via deleting these unreachable items.
It guarantees that the available memory could be used efficiently, but does not guarantee that there might be sufficient reminiscence for this system to run.
Question nine. When Does An Object Become Eligible For Garbage Collection?

Answer :

An object will become eligible for rubbish series whilst no stay thread can get entry to it.

JSP Interview Questions
Question 10. What Are The Different Ways To Make An Object Eligible For Garbage Collection When It Is No Longer Needed?

Answer :

Set all available item references to "null" once the cause of creating object is served.
Bundle com.Instanceofjava;

  class GarbageCollectionTest1

  public static void major(String [] args)

 String str="garbage series interview questions";

// String object referenced by variable str and isn't always eligible for GC yet.

 Str=null;

//String object referenced by using variable str is eligible for GC

Make the reference variable to refer to any other object. Decouple the reference variable from the item and set it confer with every other item, so the item which turned into relating to before reassigning is eligible for Garbage Collection
bundle com.Instanceofjava;

 magnificence GarbageCollectionTest2

  public static void most important(String [] args)

 String str1="rubbish collection interview questions";

String str2="Top 15 garbage series interview questions";

// String item referenced with the aid of variable str1 and str2 and isn't always eligible for GC but.

 Str1=str2;

//String object referenced by using variable str1 is eligible for GC

 

Core Java Tutorial
Question eleven. What Is Purpose Of Overriding Finalize() Method?

Answer :

The finalize() technique should be overridden for an object to encompass the easy up code or to remove the device resources that have to to be done before the item is garbage gathered.

Java-Springs Interview Questions
Question 12. How Many Times Does The Garbage Collector Calls The Finalize() Method For An Object?

Answer :

Only once.

Adv Java Interview Questions
Question 13. What Happens If An Uncaught Exception Is Thrown From During The Execution Of Finalize() Method Of An Object?

Answer :

The exception will be not noted and the rubbish collection (finalization) of that object terminates

JSP Tutorial
Question 14. What Are The Different Ways To Call Garbage Collector?

Answer :

System.Gc();
Runtime.GetRuntime().Gc();
Question 15. How To Enable /disable Call Of Finalize() Method Of Exit Of Application?

Answer :

Runtime.GetRuntime().RunFinalizersOnExit(boolean value). Passing the boolean cost  proper and false will permit or disable the finalize() call.

JMS(Java Message Service) Interview Questions