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 19182

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

2 4677

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

4 14996

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

1 4796

what is main difference between architecture,framework and design pattren

3 16011

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

4 6233

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 6517

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

4 6751

what is an object class?Explain its methods?

6 12100

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 3764

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 4618

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

Accenture, CTS,

4 19378

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

TCS,

1 5179

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

2 9537

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 13376

Post New Core Java Questions

Un-Answered Questions { Core Java }

What is equlas() and hashcode() contract in java? Where does it used?

1202

Is multiple inheritance supported by java?

1057

Does java support multiple inheritance or not?

1197

What is an inner class in java?

1025

What does sprintf return?

1118

Will set allow duplicates in java?

1030

What is <> used for in java?

1171

How many types of parsers are there?

1070

What is a parameter in matrices?

1113

Differentiate jar and war files?

1096

What do negative exponents mean?

1113

What is the locale class in java programming?

1163

Can you explain the usages of class.forname()?

1117

Is a method a function?

1101

Which class cannot be a subclass in java?

1079

For More Un-Answered { Core Java } Questions Click Here