Interview Questions and Answers - Order By Newest Q1231. Explain your experience with Java, spring and web services? General
Ans. Have worked on Java 7 and Java 8, In Java 8 , Worked with streams , lambda expression and default methods.
Have worked on both Spring Mvc and Spring Boot, using Spring dependency injection, Rest services , AOP , JDBC and Hibernate integration.
Have worked on Rest services using Spring and Spring Boot. Have worked on SOAP web services too. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  spring  web services Asked in 1 Companies Q1232. Can a constructor throw an exception ? Core Java
Ans. Yes Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q1233. Can constructor be synchronized in Java ? Core Java
Ans. No, constructors can not be synchronized in Java. In fact using the keyword synchronized with a constructor results in compilation error. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies expert Q1234. Will finally run if we have return statement and it exits the method early ? Core Java
Ans. finally will execute in all graceful situations - graceful executions as well as graceful exceptions. The only situation when finally block won't execute is when the app is abruptly stopped, killed or unplugged. Sample Code for finally Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  finally Intermediate Q1235. 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 Q1236. Why do you wan to stay in IT ? General
Ans. Coding , Science and Mathematics has always fascinated me. I have curious mindset that continuously look for solutions. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q1237. How to make sure that no request are lost in client server application ? Solution
Ans. By keeping some sort of storage at the client side for each request and then matching it up against the response received to make sure that the request was well received.
A queue can be used for this purpose. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q1238. 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 Q1239. Is it mandatory to have a default constructor ? Core Java
Ans. No.
Default constructor is provided by compiler if no constructor is provided ( argument or no argument ) by us. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  constructor  default constructor Asked in 1 Companies Try 1 Question(s) Test Q1240. What is the problem with this code
double x=10.04;
int a = x;
Ans. It will give an error saying 'cannot convert from double to int' Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q1241. 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 Q1242. Can an application have multiple main methods within different classes ? If yes, How will the app decide which one to be executed ? Core Java
Ans. Yes we can have a main method with string[] argument in every class of an application. When we execute an app we specify the starting point i.e the class that will get the control first and hence main method of that class gets executed. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  main method Asked in 3 Companies Q1243. Does importing a package imports all its sub packages too ? Core Java
Ans. No, but we can use wild card (*) to do so
For example -
import java.util.*
will import all packages with name starting with java.util Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  package   import packages Asked in 1 Companies basic Q1244. What is the default value of a declared object reference ? Core Java
Ans. Null Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  object reference  null Asked in 1 Companies basic Q1245. 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 Q1246. What are the different ways to handle an exception ? Core Java
Ans. 1. Wrap the desired code in try block followed by a catch / finally to catch the exception
2. Declare the throws clause with exceptions that the code is expected to throw as an indication to the calling method to take care of it. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  exception handling Asked in 4 Companies Try 1 Question(s) Test Q1247. 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 Q1248. Is delete a keyword in Java ? Core Java
Ans. No, delete is not a keyword in Java. Destruction of objects is taken care by Java Garbage Collection mechanism. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  delete  keywords Asked in 1 Companies Ans. No exit is a method to exit execution of a program. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  exit  keywords  exit a program Asked in 1 Companies Q1250. Who invokes a thread's run method ? Core Java
Ans. After a thread is started using a call to start method, JVM invokes the thread’s run method when the thread is initially executed. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  threads  thread run method Asked in 1 Companies 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 Q1252. 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 Q1253. 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 Q1255. 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 Q1256. Difference between shallow copy and object cloning ? Core Java
Ans. Shallow copy is one of the way for object cloning, other being deep copy. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  cloning  shallow copy  object cloning basic Ans. Shutdown hook is a thread that is invoked before the JVM is shut down. we can use it perform resource cleaning task. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  shutdown hook  jvm Try 1 Question(s) Test Q1258. 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 Q1259. 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 Q1260. Which memory segment holds String Pool in Java ? Core Java
Ans. String Pool resides in runtime constant Pool which is a part of Heap memory segment. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  string pool  memory management Expert   rare