Servlet interview questions

Fundamental Based -

1. Java revisited servlet interview questions & answers

Design related interview questions

1. Object oriented design principles
2. Software design interview questions
3. When to use interface
4. Java enum is class or interface
5. Java67 design pattern questions and answers
6. Java revisited programming interview questions
7. How to analyze the thread dump
8. Understanding various design patterns
9. UML class diagram understanding & creation
10. Points to consider while implementing Observer design pattern
11. Difference between dependency injection and dependency lookup
12. How to program multithreading communication 
13. Managing code maintainability 
14. Maintaining code robustness 
15. Implementing extensible code
16. Optimistic concurrency control concept
17. Optimistic vs Pessimistic locking in Hibernate
18. What is time complexity
19. What is big O notation 
20. How to calculate the complexity of algorithm  
21. Sorting Algorithms -
    
    • Merge Sort 
    • Insertion Sort
22. Searching Algorithms -
    
    • Hash Table  
    • Binary Search Tree
    • B Tree 
    • B+ Tree

Spring-Core interview questions

Implementation Based - 

Auto wiring -

http://www.coderanch.com/t/603029/Spring/Autowired-properies

Common Questions - http://javarevisited.blogspot.in/2011/09/spring-interview-questions-answers-j2ee.html

Fundamental - 

http://java67.blogspot.sg/2012/08/spring-interview-questions-answers.html 

1. Can we assign the reference of prototype bean to singleton bean & vise versa ?
2. Is spring singleton , singleton to class-loader or not ?
3. Difference in life cycle of singleton and prototype bean ? (hint - destroy-method execution)

Link - http://static.springsource.org/spring/docs/3.2.x/spring-framework-reference/html/beans.html#beans-factory-scopes

1. Spring annotations and their purpose
2. Difference between <context:annotation-config> and <context:component-scan>
3. Register singleton bean to spring factory using registerSingleton

Jsp interview questions

1. EL String comparision
2. EL String to number comparision
3. Revisited JSP interview question
4. Simple tag life cycle (Simple tag support)
5. Body tag life cycle (Body tag support)

Core java fundamental interview questions

1. In the non-static method, the reference to the instance of the enclosing context is passed implicitly in the constructor call of the non-static local class
2.  Equals , comparable and comparator - http://leepoint.net/notes-java/data/expressions/22compareobjects.html
3. Common Question - http://bateru.com/news/2011/03/484/
4.  Common question - http://www.fromdev.com/2010/08/10-jdbc-questions-for-java-beginners.html
5. Good questions - http://javarevisited.blogspot.in/2011/04/top-20-core-java-interview-questions.html
6. Multithreading  - http://www.fromdev.com/2008/05/java-threading-questions.html
7. Collection - http://www.fromdev.com/2008/05/java-collections-questions.html
8. Classpath - http://www.fromdev.com/2012/09/Java-Path-Classpath-Questions-Answers.html
9. Jdbc - http://www.fromdev.com/2010/08/10-jdbc-questions-for-java-beginners.html
10.  Why static method override is not allowed
11. Starting thread more than once - http://stackoverflow.com/questions/1215548/is-it-legal-to-call-the-start-method-twice-on-the-same-thread
12. Wait notify- notify all - http://javarevisited.blogspot.sg/2011/05/wait-notify-and-notifyall-in-java.html 
13. Volatile vs synchronization - http://javarevisited.blogspot.in/2011/06/volatile-keyword-java-example-tutorial.html
14. HashTable vs Concurrent HashMap vs SyncronizedMap - http://javarevisited.blogspot.sg/2011/04/difference-between-concurrenthashmap.html
15. HashSet Vs TreeSet -http://java67.blogspot.sg/2012/08/difference-between-hashset-and-treeset-java.html
16.  http://javarevisited.blogspot.sg/2011/08/what-is-polymorphism-in-java-example.html
17. http://java67.blogspot.sg/2012/08/difference-between-string-and-stringbuffer-in-java.html
18. http://javarevisited.blogspot.sg/2012/01/how-to-reverse-string-in-java-using.html
19. http://java67.blogspot.sg/2012/09/java-collection-interview-questions.html
20. http://java67.blogspot.sg/2012/09/what-is-new-in-java-7-top-5-jdk-7.html
21. http://java67.blogspot.sg/2012/08/10-java-coding-interview-questions-and.html
22. http://java67.blogspot.sg/2012/08/5-thread-interview-questions-answers-in.html
23. http://java67.blogspot.sg/2012/09/top-10-tough-core-java-interview-questions-answers.html
24. http://javarevisited.blogspot.in/2011/11/collection-interview-questions-answers.html
25. http://javarevisited.blogspot.in/2011/02/how-hashmap-works-in-java.html
26. http://javarevisited.blogspot.in/2011/04/top-20-core-java-interview-questions.html
27. http://javarevisited.blogspot.in/2012/12/difference-between-equals-method-and-equality-operator-java.html
28. http://javarevisited.blogspot.sg/2011/04/difference-between-concurrenthashmap.html
29. http://java67.blogspot.in/2012/09/java-collection-interview-questions.html

Other important questions - 

1. What are advantages and disadvantages of singleton
2. Fail safe and fail fast iterator & internal working on fail fast iterator
3. The way to synchronize hash map-
• By passing it to the constructor of HashMap
• By passing it to the constructor of HashTable
• By calling synchronizedMap method of collections class
• By providing custom synchronized implementation
4. ClassNotFoundException Vs NoClassDefFoundError
5. What is stackOverFlow Error and can it be caught 
6. New features in Java7
7. Caching on wrapper classes

Serialization interview questions - 

http://stackoverflow.com/questions/447898/what-is-object-serialization
http://javarevisited.blogspot.sg/2011/04/top-10-java-serialization-interview.html

http://www.fromdev.com/2012/06/15-java-serialization-interview.html

http://java-questions.com/Serialization-interview-questions.html

OCPJP topics

TDD implementation based interview questions

code structure while using mock - 
http://www.coderanch.com/t/603031/Testing/mock-return-method


Other important concepts -

1. Implementing Login Service in TDD way
2. TDD vs Test after approach
3. Easy mock vs Mockito
4. Comparing two file using Junit
5. TDD with spring transactional DAO layer

6. AbstractTransactionalJUnit4SpringContextTests API

Hibernate fundamental interview questions

Query cache vs second level cache -
http://www.coderanch.com/t/602070/ORM/databases/Query-Level-Cache
http://www.javalobby.org/java/forums/t48846.html
http://www.coderanch.com/t/526101/ORM/databases/Relation-Hibernate-Query-Cache-Level

Foreign key relationship managing (inverse)-
http://www.coderanch.com/t/479189/ORM/databases/inverse-hibernate
http://www.coderanch.com/t/218391/ORM/databases/Inverse

Other useful information -

1. What is inverse
2. Cascade in Hibernate
3. Hibernate fetching strategy change at run-time 
4. Hibernate query generation mechanism selection
5. Hibernate inheritance mapping strategy concept
6. Hibernate inheritance mapping strategy code
7. Hibernate implicit inheritance mapping
8. Hibernate collection and it's usage
9. Hibernate session flushing
10. Hibernate flushing strategy
11. Hibernate commit vs flush
12. Drawbacks of second level cache
13. Hibernate filters and their usage
14. Issues with primitive type mapping in Hibernate
15. Fetching strategy and their impact in sql query generation
16. Mapping  java enum to database column

Database interview questions

1. Trigger types
2. Transaction handling in oracle pl/sql
3. Clustered and Non-Clustered index 
4. SQL Query related interview question
5. Oracle general interview question - 1
6. Oracle general interview question - 2
7. Max number existing in any of the tables
8. Identifying left outer and right outer join
9. Difference between DBA and SYSDBA
10. What is table partitioning and when it should be done
11. Queries for table partitioning
12. Partitioning existing table using exchange partition
13. Partitioning existing table using dbms_redifinition
14. Getting table partition related information using all_tab_partition
15. SQL interview question series

     Analytic Interview Questions -

1. Handling table's heirarchical data in query
2. Analytical function query 
3. Analytical function based query
 

 

Core Java implementation based questions

Race Condition scenarios-

1. i++ not being an atomic operation
2. Join causes only the calling thread to wait for operation completion not to another thread calling join method on the same parent thread

Other good questions & Scenarios -

1. Develop a horse racing program
2. Scenario of identifying right monitor in thread and importance of Yield method
3. Controlling the sequence of execution in multithread scenario using wait-notify
4. Javarevisited multithreading interview questions
5. Dead lock Scenario in Money transfer module
• Buggy Code Scenario
• Solution to prevent dead lock Scenarios

Spring-orm implementation based question

Designing -
http://www.coderanch.com/t/602653/ORM/databases/dynamicall-decide-database-referred

Q- How to perform operations in transaction while using HibernateTemplate or JDBCTemplate?
Ans- a) transaction across multiple JDBCTemplate or HibernateTemplate
b) Declarative (aop or annotation base) & programmatic transaction management configuration

Q- Possible isolation levels  & propagation of a transaction and way to use it in Spring - 
http://en.wikipedia.org/wiki/Isolation_%28database_systems%29
http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/transaction.html#transaction-declarative-annotations
 http://static.springsource.org/spring/docs/1.2.9/api/org/springframework/transaction/annotation/Isolation.html 

Ques-Spring's @Transactional on class level applies to what methods?

Ans-http://stackoverflow.com/questions/28170851/springs-transactional-on-class-level-applies-to-what-methods#

Hibernate implementation based interview questions

1. Cascade and lack on inverse causing duplicate in many to many 
2. Implicit inverse in one to many relationship 
3. Implementing optimistic locking in Hibernate
4. Optimistic and pessimistic locking implementation in Hibernate
5. Using c3p0 connection pool in Hibernate
6. Using projection and distinct in detached Criteria query