Interview Questions and Answers - Order By Newest        Q631. Is there any relationship between Web.xml and Spring.xml ?  Spring 
Ans. No, there is no relationship between web.xml and spring.xml but you have to configure spring.xml in web.xml in order initialize beans when application starts up   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        spring  web.xml  spring.xml  deployment descriptor      Asked in 1 Companies   Q632. Scale yourself on Java on the scale of 1 to 10  General 
Ans. [Open Ended Answer] 
 
The objective of the question is to check how efficient one is in the language so that appropriate level questions are asked. Don't tell too high number if you are being interviewed for a junior or mid level position as the interviewer may throw advance level questions.   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve              Asked in 17 Companies   Q633. Which environment variables do we need to set in order to run Java programs?  Core Java 
Ans. PATH, CLASSPATH and JAVA_HOME   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        environment variables  path  classpath  java_home      Asked in 3 Companies        basic          frequent   Q634. Is there a way to know size of an object in Java ?  Core Java 
Ans. No, Java doesn't have a sizeOf operator. In C / C++ , its required to determine how much memory allocation is required which is not the case with Java. Java handles memory allocation and deallocation intrinsically.   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        sizeOf  size of object  sizeOf operator      Asked in 1 Companies          rare   Q635. How does Java handle integer overflows and underflows?  Core Java 
Ans. It uses those low order bytes of the result that can fit into the size of the type allowed by the operation.   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        integer  data types      Asked in 1 Companies          rare Ans. Interface that is declared inside the interface or class, is known as nested interface. It is static by default.   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        interface  nested interface       intermediate  Try 1 Question(s) Test  Q637. What kind of thread is garbage collection thread ?  Core Java 
Ans. Daemon thread   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        garbage collection       intermediate  Try 2 Question(s) Test  Q638. What is the difference between the Reader/Writer java.io hierarchy and the Stream class hierarchy?  Core Java 
Ans. The Reader/Writer hierarchy is character oriented, whereas the Stream class hierarchy is byte oriented.   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        java io  streams       intermediate Ans. It's an object that reads from one stream and writes to another.   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        java io  io filter       intermediate   Q640. Can we convert a numeric IP address to a web host name ?  Java EE 
Ans. Yes, using InetAddress.getByName("<IP Address>").getHostName();   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        ip address to hostname  INETAddress       intermediate   Q641. Which interface is responsible for transaction management in JDBC ?  Database 
Ans. Connection Interface   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        jdbc  Q642. how to access the methods of an inner class?  Core Java 
Ans. It depends on the type of inner class  
 
To access non static inner class method  
 
new OuterClass().new InnerClass().getMethod(); 
 
To access static method of static inner class 
 
new OuterClass.InnerClass().getMethod();    Sample Code for inner class   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        inner classes  nested aclasses      Asked in 1 Companies        Intermediate          frequent   Q643. What are the cursors available in Java ?  Core Java 
Ans. Enumeration 
Iterator 
List iterator   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        cursors  iterator  Q644. Which Web and Application server is being used by your application ?  Server 
Ans. We are using Apache 2.3 and Tomcat 5.6   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        web server  application server  server       Basic          frequent   Q645. How do you monitor your logs while investigating a high severity problem ?  Support 
Ans. We try to look for errors in the last n minutes when the issue occurred. If the issue is still occurring intermittently, We tail the logs for different application server instances to see the error snippets coming in the live logs.   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        production support  unix  application logs  Q646. What actions you take if there is an issue related to Database server ?  Support 
Ans. We involve DBA and try to solve it through them. By the time they are solving it , we keep the stake holders informed regarding the progress.   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        database  database server  production support  Q647. How are DB transactions handled in Hibernate ?   Hibernate 
Ans. // Non-managed environment idiom 
Session sess = factory.openSession(); 
Transaction tx = null; 
try { 
    tx = sess.beginTransaction(); 
 
    // do some work 
    ... 
 
    tx.commit(); 
} 
catch (RuntimeException e) { 
    if (tx != null) tx.rollback(); 
    throw e; // or display error message 
} 
finally { 
    sess.close(); 
}   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve              Asked in 1 Companies Ans. Its used to access the object properties using the object reference or class properties using the Class Name. Moreover its used to access the classes and Interfaces of a package.   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        operators  Q649. How should we handle errors while writing or accessing Stored Procedures?  Database 
Ans. Store Procedure returns the error code. Moreover we can put the call withing try block and catch SQL Exception.   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        stored procedure  exception handling  Q650. What is memory leak ? How Java helps countering memory leaks compared to C++ ?  Core Java 
Ans. Memory Leak is a situation wherein we have a reserved memory location but the program has lost its reference and hence has no way to access it.  
 
Java doesn't have concept of Pointers, Moreover Java has concept of Garbage collection that frees up space in heap that has lost its references.   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        memory leak  garbage collection       intermediate          frequent   Q651. What are the points to be considered if we move from Eager initialization to Lazy Initialization in Hibernate ?  Hibernate 
Ans. Make sure that the properties of dependent Hibernate entities are not accessed and if yes, better wrap the whole code within single transaction.   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        lazy loading  lazy initialization  Q652. How does Lazy Initialization helps improving performance of an application ?  Hibernate 
Ans. Lazy Initialization means , Load Dependencies when required. Which means less load on application resources as only required data is loaded upfront. It's not only good for better performance but for better resource utilization too.   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        lazy loading  lazy initialization         frequent   Q653. What are the benefits of creating immutable objects ?  Core Java 
Ans. 1. Security and Safety - They can be shared across multiple threads as they are thread safe. Moreover, it protects then from bad state due to interception by the other code segment. One such problem due to mutability and access by alternate code segment could be the change of hash code and then the impact on its search with hash collections. 
 
2. Reuse - In some cases they can be reused as only one copy would exist and hence it can be relied upon. For example - String Pool   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        immutable  immutability objects      Asked in 1 Companies        Intermediate          frequent   Q654. Can you name some of the Java frameworks in different domains ?  Frameworks 
Ans. Web Framework - Spring , Struts, Play 
Dependency Injection frameworks - Google Guice , PicoContainer and Dagger 
ORM Framework - Hibernate 
Big Data / ETL Frameworks - Apche Hadoop , Apache Crunch, Apache Spark. 
View Frameworks - JSF , Apache Wicket,jtwig. 
Java Gui Frameworks - SWT , AWT, JavaFX 
Testing - Junit, Mockito, PowerMock, EasyMock, JMock, JMockit 
Rest Web services - Jersey , Restlet , RestX, RestEasy ,Restfulie 
 
Here is the big list for reference - http://javasearch.buggybread.com/home2.php?keyword=   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        frameworks      Asked in 2 Companies        intermediate          frequent   Q655. What is the difference between  
 
File f = new File("homexyz.txt"); 
 
and 
 
File f = File.createTempFile("xyz",".txt","home"); ?  Core Java 
Ans. First will not create physical file in storage whereas the second will.   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        file handling  File.createTempFile  file handling       intermediate          rare   Q656. What is a certificate authority ?  Security 
Ans. A trusted organization which issues public key certificates and provides identification to the bearer.   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        authentication  auth certificatesAns. https://javasearch.buggybread.com/InterviewQuestions/questionSearch.php?searchOption=label'    Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        Algorithm  Sorting Algorithm      Asked in 4 Companies        basic          frequent   Q658. What will be the output of following code ? 
 
Base Interface 
 
public interface BaseInterface { 
   int i = 4; 
} 
 
Derived Interfaces 
 
public interface DerivedInterface1 extends BaseInterface{ 
   int i = 5; 
} 
 
public interface DerivedInterface2 extends BaseInterface{ 
   int i=6; 
} 
 
Implementing Class 
 
public class Class implements DerivedInterface1,DerivedInterface2 { 
   public static void main(String[] args){ 
      System.out.println(BaseInterface.i); 
   } 
} 
 
What will be the output upon executing main and Why ?  Core Java 
Ans. It will print 4 because member elements of an interface are implicitly static and hence the concept of overriding doesn't work. 
   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        interfaces  coding  code  extending interfaces  diamond interfaces      Asked in 1 Companies        intermediate   Q659. What will be the output of following code ? 
 
Base Interface 
 
public interface BaseInterface { 
   int i = 4; 
} 
 
Derived Interfaces 
 
public interface DerivedInterface1 extends BaseInterface{ 
   int i = 5; 
} 
 
public interface DerivedInterface2 extends BaseInterface{ 
   int i=6; 
} 
 
Implementing Class 
 
public class Class implements DerivedInterface1,DerivedInterface2 { 
        int i=10;    
 
        public static void main(String[] args){ 
      System.out.println(new Class().i); 
   } 
} 
 
What will be the output upon executing main and Why ?  Core Java 
Ans. 10   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        interfaces  coding  code       intermediate   Q660. What is the difference between compilation and decompilation ?  Core Java 
Ans. Compilation is the process of converting Java source files to class files which can be executed by the Java runtime environment whereas Decompilation is the process of converting class files back to the Java Source code.   Help us improve. Please let us know the company, where you were asked this question   :       Like            Discuss            Correct / Improve        compilation vs decompilation  compiler vs decompiler