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
191. What is security context ?
An object that encapsulates the shared state information regarding security between two entities.
192. What is security policy domain ?
A scope over which security policies are defined and enforced by a security administrator. A security policy domain has the following characteristics:
It has a collection of users (or principals).
It uses a well defined authentication protocol(s) for authenticating users (or principals).
It may have groups to simplify setting of security policies.
193. What is security technology domain ?
A scope over which the same security mechanism is used to enforce a security policy. Multiple security policy domains can exist within a single technology domain.
194. What is serialization ?
The encoding of objects, and the objects reachable from them, into a stream of bytes and the complementary reconstruction of the object graph from the stream.
195. What is short ?
A Java keyword used to define a variable of type short.
196. What is single precision ?
In the Java language specification, describes a floating point number with 32 bits of data. See also double precision.
197. What is SGML ?
Standardized Generalized Markup Language. An ISO/ANSI/ECMA standard that specifies a way to annotate text documents with information about types of sections of a document.
198. What is SOAP ?
The Simple Object Access Protocol (SOAP) uses a combination of XML-based data structuring and the Hyper Text Transfer Protocol (HTTP) to define a standardized method for invoking methods in objects distributed in diverse operating environments across the Internet.
199. What is SQL ?
Structured Query Language. The standardized relational database language for defining database objects and manipulating data.
200. What is static ?
A Java keyword used to define a variable as a class variable. Classes maintain one copy of class variables regardless of how many instances exist of that class. static can also be used to define a method as a class method. Class methods are invoked by the class instead of a specific instance, and can only operate on class variables.