Core Java Interview Questions, Answers for Freshers and Experienced asked in various Company Job Interviews

Core Java Interview Questions

Questions Answers Views Company eMail

Can we place the any object to key attribute of HashMap?

HCL,

4 19021

Hi friends, i am new to java. can you explain how java is secured.

2 4550

Hi Friends, can u give me Real Time example for interface and abstract class.(With Banking Example)

4 14836

when to use ArrayList and when to use HashMap in webApplication.

1 4707

what is main difference between architecture,framework and design pattren

3 15876

Hi Friends, can you explain instance in java. In general instance means "occurence of something" . In java what is instance.

4 6053

Hi Friends, I am beginner in java. what i know about synchonized keyword is,If more that one 1 thread tries to access a particular resource we can lock the method using synchronized keyword. Then after that how the lock is released and how next thread access that.Please explain with example.

5 6351

Hi Friends, can you give difference between extending thread class and implementing runnable interface.

4 6563

what is an object class?Explain its methods?

6 11918

Hi Friends, I am new to java. Can u explain about thread concept.How i know one thread is locked, and how can i force or acquire another thread for lock . Finally how to know thread is released from lock. Explain types of lock(like method level and block level) in thread.

1 3667

I have a sorting issue with a Hashmap. My constraint is that I MUST use the Hashmap and work with existing code. I do a database query and place the results in a Hashmap. When I iterate thru the Hashmap, it loses the original alphabetical sorting done by the database. So, my problem is that I must sort the results coming out of the Hashmap which is then placed into another class.

1 4508

What is Session and cookies?Explain in detail with an example?

Accenture, CTS,

4 19215

I need to know about complete topic in java's collections i with an examples

TCS,

1 5073

Real Time sample code for Encapsulation and Abstraction. where to use abstract and where to use specifies like public private.

2 9423

What will happen inside init() in servlet. my interviewer asked servlet lifecycle. i said "once servlet is loaded in to memory init() will be called which performs servlet initialization " . Again interview asked what values will be initialized . what is difference between init() and init(ServletConfig config).

Infinite Computer Solutions, TCS,

2 13279

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Un-Answered Questions { Core Java }

What is locale?

1033

What is the use of predicate in java 8?

963

Can we create more than one object singleton class?

1038

What is the platform?

1002

Write a java program to generate fibonacci series ?

1071

What does the append?

1001

What is the purpose class.forname method?

964

What is the default size of arraylist in java?

1128

Why java is a platform independent? Explain

1090

What is parsing a string?

1172

Why does java not support operator overloading?

1140

Explain reverse a linked list iterative solution in java?

925

What does @override mean?

1206

What restrictions are placed on method overloading?

1178

Can java run on google chrome?

1195

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