Latest F2F Interview Questions ( J2EE )

1. What is concurrenthashmap & it’s functionality as well as identityhashmap3. What is anonymous class and where it’s used?
4. Difference between fail-fast and fail-safe?
5. Why marker interface?
6. How many classloaders are there in java?
7. How to write thread without class?
8. Explain about Hashing?
9. Where to check browser version whether JSP or JS?
10. How to handle multiple request?
11. How to add two number without an operator?
12. What is the use of deeptostring in Arrays class?
13. Why we are using wrapper classes in java?
14. Java is pure object oriented programming language or not?
15. Can extend abstract class into another abstract class if yes means when it’s extend?
16. Difference between stateless and stateful protocol?
17. Difference between hashcode and equals?
2. How to handle multiple submission in web page?

30 Most Asked Java Exception Handling Interview Questions And Answers

1) What is an exception? 
2) How the exceptions are handled in java? OR Explain exception handling mechanism in java? 
3) What is the difference between error and exception in java? 
4) Can we keep other statements in between try, catch and finally blocks? 
5) Can we write only try block without catch and finally blocks? 
6) There are three statements in a try block – statement1, statement2 and statement3. After that there is a catch block to catch the exceptions occurred in the try block. Assume that exception has occurred in statement2. Does statement3 get executed or not? 
7) What is unreachable catch block error? 
8) Explain the hierarchy of exceptions in java? 
9) What are run time exceptions in java. Give example? 
10) What is OutOfMemoryError in java? 
11) what are checked and unchecked exceptions in java? 
12) What is the difference between ClassNotFoundException and NoClassDefFoundError in java? 
13) Can we keep the statements after finally block If the control is returning from the finally block itself? 
14) Does finally block get executed If either try or catch blocks are returning the control? 
15) Can we throw an exception manually? If yes, how? 
16) What is Re-throwing an exception in java? 
17) What is the use of throws keyword in java? 
18) Why it is always recommended that clean up operations like closing the DB resources to keep inside a finally block? 
19) What is the difference between final, finally and finalize in java? 
20) How do you create customized exceptions in java? 
21) What is ClassCastException in java? 
22) What is the difference between throw, throws and throwable in java? 
23) What is StackOverflowError in java? 
24) Can we override a super class method which is throwing an unchecked exception with checked exception in the sub class? 
25) What are chained exceptions in java? 
26) Which class is the super class for all types of errors and exceptions in java? 
27) What are the legal combinations of try, catch and finally blocks? 
28) What is the use of printStackTrace() method? 
29) Give some examples to checked exceptions? 
30) Give some examples to unchecked exceptions? 

25 Java Array Interview Questions And Answers

1) What is ArrayStoreException in java? When you will get this exception? 
2) Can you pass the negative number as an array size? 
3) Can you change the size of the array once you define it? OR Can you insert or delete the elements after creating an array? 
4) What is an anonymous array? Give example? 
5) What is the difference between int[] a and int a[] ? 
6) There are two array objects of int type. one is containing 100 elements and another one is containing 10 elements. Can you assign array of 100 elements to an array of 10 elements? 
7) “int a[] = new int[3]{1, 2, 3}” – is it a legal way of defining the arrays in java? 
8) What are the differences between Array and ArrayList in java? 
9) What are the different ways of copying an array into another array? 
10) What are jagged arrays in java? Give example? 
11) How do you check the equality of two arrays in java? OR How do you compare the two arrays in java? 
12) What is ArrayIndexOutOfBoundsException in java? When it occurs? 
13) How do you sort the array elements? 
14) How do you find the intersection of two arrays in java? 
15) What are the different ways of declaring multidimensional arrays in java? 
16) While creating the multidimensional arrays, can you specify an array dimension after an empty dimension? 
17) How do you search an array for a specific element? 
18) What value does array elements get, if they are not initialized? 
19) How do you find duplicate elements in an array? 
20) What are the different ways to iterate over an array in java? 
21) How do you find second largest element in an array of integers? 
22) How do you find all pairs of elements in an array whose sum is equal to a given number? 
23) How do you separate zeros from non-zeros in an integer array? 
24) How do you find continuous sub array whose sum is equal to a given number? 
25) What are the drawbacks of the arrays in java? 

HCL interview questions ?

Q1- How can get third highest values from inter Array.

Q2- Difference b/t Array.short() and Collection.Short() method.

Q3- Difference b/t application server and web server.

Q4- What is soap and rest full.
Q5- Difference b/w soap and rest.

Q5- Flow of Soap  .

Q6- How can work soap and which protocol use.

Q7.- Volatile keyword.

Q8. what is Singleton

Q9- Can we use Singleton in Singleton.

Q10 - how can manage singleton in Multithreading.

Q11- Difference EJB3 and ejb 2

Q12- How we can do memory management and memory allocation.

Q14- Cololection framwork hierarchy.

Q15- how tree set and linked work internally.

Q16 -LatchCountDown

Q17-String mutable or imutable meanning.

Q18- Jboss configuration.

Q19-- JPA

20- how can destroy hibernate session.