Interview Questions and Answers - Order By Newest Q691. If you are given choice to avoid LazyInitializationException using any of the following measures, which are the ones you will choose and why ?
1. Set lazy=false in the hibernate config file.
2. Set @Basic(fetch=FetchType.EAGER) at the mapping.
3. Make sure that we are accessing the dependent objects before closing the session.
4. Force initialization using Hibernate.initialize Hibernate
Ans. First resolution is a big No as it conveys no lazy loading in complete app. even second is advocating the same but for a particular mapping.
third one is most appropriate if loading and dependent entity property access is closer to each other in code and can be accomplished.
I don't mind using 4th too. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  lazy loading  lazy initialization  LazyInitializationException Q692. What was the worst problem you faced while working with Hibernate ? Hibernate
Ans. Lazy Initialization exceptions Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Q693. Is it advisable to keep session or transaction open for long time just to avoid LazyInitializationException ? Hibernate
Ans. No. It's a resource and performance overhead. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  LazyInitializationException  Lazy Loading Q694. How to create list that will sort it's elements dynamically? Algorithm
Ans. Override the behavior of collection class to sort the list upon each element addition. Though it's not recommended as list are sorting heavy data structures.
List<MyType> list = new ArrayList<MyType>() {
public boolean add(MyType mt) {
super.add(mt);
Collections.sort(list, comparator);
return true;
}
}; Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies intermediate Q695. Write program to create a linked list and perform different operations on it. Algorithm
Ans. import java.util.*;
class LinkedListSolution{
protected LinkedList list;
public LinkedListSolution(){
list = new LinkedList();
}
public Object pop() throws NoSuchElementException{
if(list.isEmpty())
throw new NoSuchElementException();
else
return list.removeFirst();
}
public void push(Object obj){
list.addFirst(obj);
}
public Object peek() throws NoSuchElementException{
if(list.isEmpty())
throw new NoSuchElementException();
else
return list.getFirst();
}
public boolean isEmpty(){
return list.isEmpty();
}
public String toString(){
return list.toString();
}
}
class TestStack{
public static void main(String args[]){
LinkedListSolution s = new LinkedListSolution();
s.push("First");
s.push("Second");
s.push("Third");
System.out.println("Top: " s.peek());
s.push("Fourth");
while(!(s.isEmpty()))
System.out.println(s.pop());
}
} Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  Linkedlist  data structures  algorithm Asked in 2 Companies basic Q696. Can the foreign key column have null values ? Database
This question was recently asked at 'Volkswagen It services'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q697. How do threads share information ? Core Java
Ans. Through common memory area. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  threads Asked in 1 Companies Q698. What is the precedence of operators in Java ? Core Java
Ans. http://introcs.cs.princeton.edu/java/11precedence/ Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  operators  operator precedence basic Ans. Access Control List or ACL is the list of permissions attached to an object in the File System. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  acl  file system  file security  object security  operating system Q700. Write a Program to delete a node from Linked List ? Data Structure
This question was recently asked at 'Caprus IT'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  linkedlist  delete a node from linked list Asked in 1 Companies Q701. how many reducer task runs on a hadoop cluster ? BigData
Ans. Generally one reducer runs for all mappers, but it can be increased as per requirements. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  Hadoop  BigData Asked in 1 Companies This question was recently asked at 'Veritas'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  Mutex vs Semaphore Asked in 1 Companies This question was recently asked at 'Veritas'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies This question was recently asked at 'Veritas'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies This question was recently asked at 'Veritas'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q706. What data structure will you use if we have to search an element in million of elements ? Data Structure
This question was recently asked at 'Microsoft'.This question is still unanswered. Can you please provide an answer. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  Search Asked in 1 Companies Q707. What is priority inversion inheritance method?
Ans. https://en.wikipedia.org/wiki/Priority_inversion Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Ans. Priority inversion is a problematic scenario in scheduling in which a high priority task is indirectly preempted by a lower priority task effectively inverting the relative priorities of the two tasks. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 5 Companies Q709. Does Hibernate synchronize entity with the database automatically i.e any change to entity gets updated in DB ? Hibernate
Ans. Yes, the feature is there but can be override with changing the Flush Mode. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Q710. How can we make sure that Hibernate doesn't update the entity changes to DB or how to keep the entity detached ? Hibernate
Ans. If it's only a read only transaction, we can wrap the get / load call in read only transaction.
If we want it to be application wide, we an set the flush mode accordingly or else we can evict the entity object to remove them from session. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Try 2 Question(s) Test Q711. What is the difference between session.clear and session.evict ? Hibernate
Ans. session.clear clears all the objects from session whereas session.evict is used for evicting a particular entity. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  hibernate session clear  hibernate evict Try 2 Question(s) Test Q712. What is the use of Hibernate session.clear() ? Hibernate
Ans. It is used to clear the session and is used to dissociate disconnect all the objects from the session. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  hibernate session clear Q713. What is the use of Hibernate session.evict()? Hibernate
Ans. It is used to dissociate / disconnect a particular object from the session. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  hibernate session evict  hibernate evict Q714. What are the benefits of using Prepared statements ? Database
Ans. 1. Precompilation , DB-side caching and reuse of same execution plan leads to overall faster execution.
2. Automatic prevention of SQL injection attacks by escaping special characters Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  Prepared statements  benefits of prepared statements Asked in 1 Companies Try 1 Question(s) Test Q715. What are the benefits of using prepared statements ? Does that benefit extend only if similar prepared statements are used within a application or it extends even with multiple applications having similar prepared statement ? Database
Ans. Prepared Statements helps in reuse of database execution plan which can be cached at Database level and hence helps achieving faster execution and performance. As cached ps objects are creating at Database level and not application level, the use and benefit extends across multiple applications. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  Prepared statements  benefits of prepared statements Asked in 1 Companies Try 1 Question(s) Test Q716. Where the prepared Statement object creating - In Java application or DB ? Database
Ans. Prepared Statement objects are created and cached at database level. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  Prepared statements Asked in 1 Companies Try 1 Question(s) Test Q717. What are the core interfaces in Hibernate? Hibernate
Ans. Session,SessionFactory,Configuration,Transaction,query and Criteria Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  core interfaces of Hibernate Asked in 1 Companies   frequent Try 1 Question(s) TestAns. Mutator is another name for setter methods, i.e the method allows for mutating the property of an object and eventually the state of the object. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  setter method  mutator Q719. Which are the most commonly used Design Patterns ? Design
Ans. Builder ( While Writing Unit Tests )
Prototype ( Cloning )
Adapter ( asList , toString )
Chain Of Responsibility ( Logging )
Singleton
Factory ( Action Mapping )
Proxy
Observer ( Event Listener )
MVC ( Web frameworks )
Filter ( Criteria ) Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  Design Patterns  widely used Design patterns intermediate   frequent Try 1 Question(s) Test Q720. Is it a good practice to override static methods ? Design
Ans. Though it's useful but it's not as useful as overriding member or object methods. We cannot achieve polymorphic behavior with static methods by overriding their definition in derived class. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  override static methods