Technical interview questions and answers are essential for J2SE Interviews because core Java concepts form the foundation of all Java-based development. Companies test your knowledge of OOP principles, exceptions, packages, JVM architecture, threading, collections, and file handling. These topics commonly appear in placement drives and technical interviews conducted by TCS, Infosys, Wipro, Cognizant, and Capgemini. Understanding J2SE concepts helps freshers and job seekers prepare for both Java developer roles and advanced J2EE/Java EE interviews. This guide features the most commonly asked J2SE interview questions with answers explained in simple language. Preparing these questions will strengthen your Java basics and improve your performance in coding tests and technical rounds.
Java programmers should advance their enterprise skills by studying J2EE frameworks and mastering EJB components for distributed applications
Showing 10 of 237 questions
181. What is RMI ?
See Java Remote Method Invocation.
182. What is rollback ?
The point in a transaction when all updates to any databases involved in the transaction are reversed.
183. What is root ?
In a hierarchy of items, the one item from which all other items are descended. The root item has nothing above it in the hierarchy. See also hierarchy, class, package.
184. What is RPC ?
Remote Procedure Call. Executing what looks like a normal procedure call (or method invocation) by sending network packets to some remote host.
185. What is runtime system ?
The software environment in which programs compiled for the Java virtual machine1 can run. The runtime system includes all the code necessary to load programs written in the Java programming language, dynamically link native methods, manage memory, handle exceptions, and an implementation of the Java virtual machine, which may be a Java interpreter.
186. What is SAX ?
Simple API for XML. An event-driven, serial-access mechanism for accessing XML documents.
187. What is sandbox ?
Comprises a number of cooperating system components, ranging from security managers that execute as part of the application, to security measures designed into the Java virtual machine1 and the language itself. The sandbox ensures that an untrusted, and possibly malicious, application cannot gain access to system resources.
188. What is scope ?
A characteristic of an identifier that determines where the identifier can be used. Most identifiers in the Java programming environment have either class or local scope. Instance and class variables and methods have class scope; they can be used outside the class and its subclasses only by prefixing them with an instance of the class or (for class variables and methods) with the class name. All other variables are declared within methods and have local scope; they can be used only within the en
189. What is Secure Socket Layer (SSL) ?
A protocol that allows communication between a Web browser and a server to be encrypted for privacy.
190. What is security attributes ?
A set of properties associated with a principal. Security attributes can be associated with a principal by an authentication protocol.