Java is an object-oriented, cross platform, multi-purpose programming language produced by Sun Microsystems, later
acquired by Oracle Corporation. One thing that distinguished Java from some other languages is its ability to run the same compiled
code across multiple operating systems. In other languages, the source code (code that is written by the programmer), is compiled by
a compiler into an executable file. This file is in machine language, and is intended for a single operating system/processor
combination, so the programmer would have to re-compile the program seperately for each new operating system/processor combination.
Java is different in that it does not compile the code directly into machine language code. Compilation creates bytecode out of the
The heart of the Java platform is the concept of a "virtual machine" that executes Java bytecode programs. This
bytecode is the same no matter what hardware or operating system the program is running under. There is a JIT (Just In Time) compiler
within the Java Virtual Machine, or JVM. The JIT compiler translates the Java bytecode into native processor instructions at run-time
and caches the native code in memory during execution.
Although Java programs are cross-platform or platform independent, the code of the Java Virtual Machines (JVM) that
execute these programs is not. Every supported operating platform has its own JVM.
The Spring Framework provides a comprehensive programming and configuration model for modern Java-based enterprise applications - on any kind of
deployment platform. A key element of Spring is infrastructural support at the application level: Spring focuses on the "plumbing" of...
RESTful web services are built to work best on the Web. Representational State Transfer (REST) is an architectural style that specifies constraints,
such as the uniform interface, that if applied to a web service induce desirable properties, such as performance, scalability, and modifiability...
A collections framework is a unified architecture for representing and manipulating collections. Java Collections Framework
reduces programming effort, increases program speed and quality, allows interoperability among unrelated APIs, fosters software reuse.
A data structure is a particular way of storing and organizing data in a computer so that it can be used efficiently.
Data structures provide a means to manage large amounts of data efficiently. efficient data structures are a key to designing efficient algorithms.
We have collected list of java interview programs from few software engineers and also with my personal experience. In this
section, we are trying to give you the best solutions for these problems. Good interviewers are more interested in your ability to code.
A sorting algorithm is an algorithm that puts elements of a list in a certain order. The most-used orders are numerical order and
lexicographical order. Efficient sorting is important for optimizing the use of other algorithms such as search and merge...
JDBC stands for Java Database Connectivity. JDBC API is a collection of classes and interfaces, which help a Java application to
connect to SQL based relational databases by abstracting vendor specific details of the database. JDBC enables Java developers to connect to...
Java Annotations are also called Metadata. Annotations are introduced with JDK 5 onwards. Annotations allows us to add some form of metadata
information into our source code, but it doesnot change the execution flow of the program. These annotations...
What is wrapper class?
Everything in java is an object, except primitives. Primitives are
int, short, long, boolean, etc. Since they are not objects, they cannot
return as objects, and collection of objects. To support this, java provides
wrapper classes to move primitives to objects. Some of the wrapper classes
are Integer, Long, Boolean, etc.
Insanity: doing the same thing over and over again and expecting different results.
-- Albert Einstein