Java

Java is a set of computer software and specifications developed by Sun Microsystems, which was later acquired by the Oracle Corporation, that provides a system for developing application software and deploying it in a cross-platform computing environment. Java is used in a wide variety of computing platforms from embedded devices and mobile phones to enterprise servers and supercomputers.

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Spring Framework

The Spring Framework provides a comprehensive programming and configuration model for modern Java-based enterprise applications - on any kind of deployment platform. A key element of Spring is infrastructural support at the application level: Spring focuses on the "plumbing" of enterprise applications so that teams can focus on application-level business logic, without unnecessary ties to specific deployment environments.

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Hibernate Framework

Hibernate ORM is an object-relational mapping framework for the Java language. It provides a framework for mapping an object-oriented domain model to a relational database.

Saturday, October 24, 2015

Interview Questions


  • Face to Face Interview Questions
  • Core Java Interview Questions
  • JDBC Interview Questions
  • Servlets Interview Questions
  • JSP Interview Questions
  • Spring Interview Questions
  • Hibernate Interview Questions
  • AngularJS Interview Questions
  • Struts Interview Questions

Friday, October 23, 2015

Face to Face Java Interview Questions for Freshers and Experienced


In this post, we are going to see some of the interview question asked while attending face to face.

Note: Here Company-1, Company-2 ...... are Some company names.

Company - 1:

1. Write a java program to print the following pattern:
   *
   *    *
   *    *    *
   *    *    *    *
   *    *    *    *    *
   *    *    *    *    *    *
2. Write a Collection hierarchy.
3. Write a Exception hierarchy.
3. What are different types of exception?
4. If you are not handling runtime exceptions why we want to write try and catch block.
5.  It is possible with out execute finally block to exit that method.
try {

} 
catch() {

}
finally {

}   
6. What is the output of the following program.
try {
     return 10 + 20;
} 
catch() {

}
finally {
     return 10 - 20;
}
7. How to handle a exception handling in the following flow:
   View    -->    Controller -->   Service   --> DAO
8. Java supports multiple inheritance or not?
9. What is the output of the following program.
interface A {
     public final static int MAX = 100;
}   
   
interface B {
     public final static int MAX = 100;
}      

class C implements A, B {
   
}
10. What is the output of the following program.
interface A {
     public final static int MAX = 100;
}   
   
interface B {
     public final static int MAX = 100;
}      

class C implements A, B {
   public static void main(String args[]) {
    System.out.println(MAX);
   }
}
11. What is the output of the following program
public void test(byte b ) { Syso("byte value"); }
public void test(int i) { Syso("int value"); }
public void test(Integer i) { Syso("Integer value"); }  
public void test(int ..args) { Syso("var args value"); }    

What is the output of the following program:    
test(100);
test(10000);
12. What is the output of the following program
public void test(byte b ) { Syso("byte value"); }
public void test(Integer i) { Syso("Integer value"); }  
public void test(int i) { Syso("int value"); }
public void test(int ..args) { Syso("var args value"); }    

What is the output of the following program:    
test(100);
test(10000);
13. What is Generalization?
14. Assume we have tables Patient and Doctor.
Patient table:
pid  pname    did
-----------------
1      a      3
2      b      2
3      c      2
4      d      1
5      e      3
6      f      null
    
Doctor table:
did  dname  specialization
-------------------------
1     aa      neurology
2     bb      pathology
3     cc      gynecology
        
Display the output in the following format. 
did dname count(pid)
15. In hibernate how to achieve one to many relationship.
16. In hibernate how to achieve many to many relationship. How many classes is needed and how many tables is needed for implementing many to many relationship.
17. Explain Servlet Life Cycle.
18. How to create a singleton object with thread safe.
19. How to display both key and values while iteration. Write the logic.
20. What is difference between Comparator and Comparable.
21. Assume i have person class with the fields id, name, age etc.
How to sort person class object values with id or name or age.
22. It is possible to store the person object hashmap. If it possible how?


Company - 2:
1. Explain about Relationship, Aggregation and Composition. Can you explain above relationship using Library, Student and Book.
2. What are the different ways to create a bean in Spring.
3. What is bean preprocessor and postprocessor.
4. What is fail fast and fail safe iterators.
5. How to get value using hashmap.
6. Assume i have string contains huge data. What is the best approach to find duplicate characters.


Company - 3:
1. Explain Oops Concepts?
2. Explain Abstraction. Can you give one realtime example?
3. Why string is immutable.
4. How many objects is created for the below program.
String s1 = "ranga";
String s2 = s1 + "reddy";
String s3 = "hi" + s2;
5. How Hashmap works.
6. What is Synchronization. Who will lock the object.
7. What is Serialization. What is the use of Serialization.
8. Write a sample program using Externilzable interface.
9. What is difference between Filter, Interceptor?
10. Write a Singleton program using double checking? We should not clone the singleton object.
11. What is difference between Factory design pattern and abstract factory design pattern. Can you give one Java API example.
12. How to redirect a request from one servlet to another servlet.
13. How to avoid duplicate submit the form.
14. How to achieve inheritance through spring configuration file.
15. What are the Spring bean scopes.
16. What is a functional programming language?
17. What is Java 8 features?
18. Can you write a sample program using lambda expressions.
19. What is callable interface?
20. In hibernate, for @onetomany annotation what are the attributes we need to pass.
21. What is difference between Left Inner Join and Right outer join.
22. Can you explain ACID Properties.
23. What is difference between Git and Subversion.


Company - 4:
1. What are the spring scopes.
2. What are the technologies you learnt recently.
3. Why Cassandra.
4. What is the use of Cassandra.


Company - 5:
1. What is difference between Abstraction and Encapsulation.
2. What is difference between wait() and wait(long) method.
3. What is difference between wait() and sleep(). If you call notifyAll() what happens in wait() method and sleep().
4. What is difference between abstract class and interface.
5. Who will lock the thread.
6. What are the spring scopes.
7.
<bean id="aBean" class="A" scope="singleton">
    <bean id="bBean" ref="bBean">
</bean>
     
<bean id="bBean" class="B" scope="prototype">
</bean>
What happens if i call aBean 3 times. How many B bean objects is created.
8. Write a program @manytomany association using student and course.
9. What is difference get() method and load() method.
10. What is difference between jdbc and orm.
11. What is difference between jpa and hibernate.
12. Assume there is form. There we can enter employee id and submit.
There is a sql query like "delete from employee where employee_id = "+id;
Now enter the employee_id value will be 100 or 1 == 1 and submit the form.
What happened. How to avoid sql injection.
13. Explain Spring MVC flow.
14. What is difference between @Component, @Controller, @Service, @Repository
15. How to handle Security in Restful Web Services.
16. What is the way to avoid changing the Collection values.
17. What is difference between hashmap and linkedhashmap.
18. How to sort the Custom Class values.
19. Explain how hashmap works.
20. How to lock the thread.
21. What are the different levels of locking in hibernate.
22. What is a Spring Transaction. What are the propegastion and  isolation levels.
23. Assume there is a relation ship.
                           RBI

SBI   Indian  Canara
When i change any thing on the RBI class it needs to notify to all sub classes for this one which design pattern you will use.
24. What is Factory design pattern.
24. String is immutable class. What is the use of making String class is immutable.
25. Immutable class uses the which design pattern. Can you give few immutable classes.
26. What is difference between forward() and include() method.
27. What is difference between page, pageContext and applicationContext.
28. What is the difference between Comparable and Comparator.
29. If i have more updation and deletion which collection you will prefer.
30. Reverse the string with out using the any JAVA API.
31. What is DAO design pattern. What are the advantages while using DAO design pattern.
32. In order to interact with hibernate what are the steps we need to do.
33. What are the roles and responsibilities.
34. Tell me about your self.
35. How to handle performance.


Company - 6:
1. Tell me about your self.
2. What are design patterns you worked.
3. Write the Factory design pattern.
4. How to interact with multiple systems.
5. How to ensure one of the server is done but data needs to be consistent.
6. Do you know JMS. Can you explain architecture of JMS.
7. How many squares are there in chess board.



Company - 7:
1. Tell me about your self.
2. About the Project.
3. Why Collections.
4. Difference between array and array list.
5. Which collection you will prefer for avoiding duplicates.
6. Why angularjs.
7. Why Spring.
8. Can you explain how request and response we can get in Spring.


Company - 8:
1. What is serialization. If i make any variable as static what will happen. If i make any variable as volatile what will happen.
2. Who will do the serialization.
3. Can you tell what are all the methods available in Serilizable interface.
4. What is cloning. What are the different types of Cloning. Can you write the program.
5. Why web services. Can you explain what are the types of web services available.
6. Can we use Servlet as a WebService.
7. What is DAO pattern. Can you write one sample program. What are all the advantage of using DAO pattern.
8. Can you explain Singleton design pattern. What are all advantages of creating singleton object as lazy and eagar.
9. What is multi threading. When we can use Threads.
10.
class Test extends Thread {
    public void synchronized test() {
    // some logic
    }
}
        
class Main {
    public static void main() {
      Test t1 = new Test();
      Test t2 = new Test();
                
      t1.start();
      t2.start();           
      t1.test();
      t2.test();
    }
}   
Now while calling t1.test() and t1.test(); test() method will execute serially or not.
11. Difference between List and Set.
12. How hashmap works.
13. What is actions and directives in JSP.
14. How to deploy war in tomcat. What are the difference ways is available.
15. While deploying War file into tomcat, if you dont have permissions how to deploy.
16.
Emp_Id     Allowance_type  Salary
----------------------------------
 1            HRA           2000
 1            DA            1500         
 2            HRA           3000
 2            DA            2000
-----------
a) Write a query to find out the sum of salary of each employee.
b) Write a query to find out the sum of salary of each employee and salary greater then 3000.
17. What will be the output of the following program.
public int getValue() {     
     int x = 10;
     try {
        return x;
     } finally {
         x++;
     }  
}
18. What the difference between NoClassDefFoundError and ClassNotFoundException
19. Explain about project.
20. What are the different types of exceptions.
21. What are the different types of Statements in JDBC.
22. Where preparedstatement plan will be stored either java heap memory or database.
23. How to access java script variable value into java in jsp page.
24. What is AJAX.


Company - 9:
1. Java5 Features
2. What is enum.
3. How hashmap works.
4. What is IOC.
5. Can you explain Spring MVC flow.
5. Why cassandra is column - oriented database.
6. What is CAP theorem.
7. What is Round Robin Algorithm
8. Why AngularJss.
9. Architecture of AngularJs.
10. In angularjs how to manipulate DOM.
11. Can you different events in angularjs.


Company - 10:
1) In browser after hitting url how the request processing is doing.
2) How serialization works where serializable interface is a marker interface.
3) Write a customized Doubly linked list program using Java.
4) Explain about Autoboxing
5) Calling destroy method from service
6) Inheritance concept  for beans in spring.
7) Default access modifier
8) Default access modifier for interface.
9) Circular dependency
10) Volatile keyword
11) Multi threading
12) Write a Java program to print the numbers using following pattern.
1
2 3
4 5 6
7 8 9 10
13) Scriptlets
14) CRON expressions
15) Wrapper classes function overloading.


Company - 11:
1. What are the OOPs concepts in Java script.
2. How to share the data between two controllers.
3. Can you write one sample angularjs application.
4. What happen if i am not passing arguments to the function.
var myApp = angular.module('myApp',[]);

myApp.controller('TestController', ['$scope', function(scope) {
scope.name = 'Ranga Reddy';
}]);
5. How to achieve toggle using programmatically in angularjs.
6. Assume list of rows is there. If i click on any row it needs to open. If i click on other row what ever row previously opened needs to close. Newly selected row needs to open.
How to achieve in angularjs.
7. Can you tell what are the directives used in your application.


Company - 12:
1. Can you tell me about your self and what are the technologies you worked.
2. How to share the data between two controllers.
3. How to achieve multiple inheritance in java.
4. What is the difference between method overloading and overriding.
5. Have you worked on Collections. Suppose i have Employee class with the id, name, age, salary fields. I have array list of 10 employee objects. How to sort the employees object using salary.
6. Have you worked on JSPs.
7. How to create a Custom directive in angularjs.
8. How to achieve two way data-binding.
9. What are the different types of Scopes in angularjs.
10. Have you worked on Restful web services.
11. How to call web services in angularjs.



Happy Learning!