Java Interview Questions

What is JDK
Describe the key steps in which a Java class is loaded by the JVM?
What are runtime data areas?
How is a java program executed by JVM?
Explain how Java programs are executed by the JVM?
What is the Java bytecodes?
What is the difference between JVM, JRE and JDK?
How is Java programming language machine and platform independent?

Java opps Questions
What is the importance OOPs in Java?
What are some major OOPs languages?
Can we run a Java application without implementing the OOPs concept?
how to maintain Garbage Collection in OOPs?
What are the constraint of OOPs?
What are some other programming standards other than OOPs?
Java String Questions
What is the meaning of String
What is the need for String
What are the main features of OOPs
why do use string
What are some advantages of using Strig?
what are the type of string
Why String is pool String
what are the ways to create string
What is the difference between == operator and equals method
Java Exception Questions
what are the type of exception
How the exceptions are handled in java
Can we have try without catch block in java ?
What is RunTime exception in java?
Can we keep other statements in between try, catch and finally block?
Can we keep the statements after finally block If the control is returning from the finally block itself?
What is Re-throwing an exception in java?

Java Collection Questions
how to sort the Collection objects in Java?
What are the ways to remove duplicates from ArrayList?
What is WeakHashMap
What are the methods to make collection thread-safe?
What is the peek()of the Queue interface?
How to join multiple ArrayLists?
What is map. entry In Map?
What is the Properties file in collection?
Java Thread Questions
What is Thread Scheduler and Time Slicing?
Can two threads execute static and non static methods concurrently?
What is a daemon thread?
What is deadlock
What is ThreadLocal in java
Thread vs Runnable which is better approach to create a thread?
what are the differenent type of states of thread in java?
Can we start a thread twice in java?
Java Spring Questions
What is the importance of the annotation @Primary
Explain Bean creation process?
Explain the process of creating an ApplicationContext in Spring.
List out all the concepts that are available in the MVC Architecture
Spring vs Spring MVC vs Spring Boot
Java Springboot Questions
What are the advantages of using Spring Boot?
Why Spring Boot over Spring?
How does Spring Boot works?
What is the purpose of using @ComponentScan in the class files?
What is the starter dependency of the Spring boot module?
What is the use of Profiles in spring boot?
What are the actuator-provided endpoints used for monitoring the Spring boot application?

Java Webservice Questions
What is WSDL?
What are some important annotations for JAX-WS?
What are HTTP methods that can be used with Restful web services?
What are some important annotations which you use to create Restful web services?
what are things consist in JAXR architecture
what is the difference between UDDI, DISCO and WSDL?
what is the difference between REST and SOAP web services?
What are the methods to create web services?
NodeJs Questions
What is the advantage of the Node.js frameworks?
What is the exit code in Node.js
How many types of API functions are there in Node.js?
error-first callback in Node.js
What is the Reactor Pattern in Node.js?
What are the main differences between spawn() and fork() methods in Node.js?
What is the purpose of ExpressJS package in Node.js?
Explain the security mechanism of Node.js?

Cucumber Questions
What is Gherkin Language?
What are the primary keywords in Cucumber?
What do you mean by scenario in Cucumber Testing?
What are annotations in Cucumber?
What are hooks in Cucumber?
What is Cucumber Dry Run?
Why do we need to use Cucumber with Selenium?
How can you run Cucumber tests parallelly?
Selenium Questions
What are the advantage of Automation Testing?
Why should Selenium be selected as a test tool?
What are the different components of Selenium?
What are test types that are supported by Selenium?
What do you mean by Selenese?
What are the different ways of locating a web element in Selenium?
what are types of WebDriver API's are available in Selenium?
What are the different types of annotations which are used in Selenium?