simple, object oriented, and familiar
robust and secure
architecture-neutral and portable environment
high performance
interpreted, threaded, and dynamic

Java lets application developers "write once, run anywhere". Java is currently one of the most popular programming languages in use, and is widely used from application software to web applications. Java runs on more than 850 million personal computers worldwide, and on billions of devices worldwide, including mobile and TV devices. State-of-the-art utilities, games, and business applications are typically compiled to bytecode (class file) that can run on any Java Virtual Machine (JVM) regardless of computer architecture. Java is a general-purpose, concurrent, class-based, object-oriented language that is specifically designed to have as few implementation dependencies as possible.

Java programming language was originally developed by James Gosling at Sun Microsystems (sold to Oracle Corporation). Java was released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities.


Compiles Java source files (*.java) to Java bytecode files (*.class)

javac [info] [JDK from Sun Microsystems (now Oracle)] (open-source)
GCJ [gcc which compiles other languages besides Java] (open-source)
ECJ [Eclipse Compiler for Java] (open source)

Java decompilers

Decompile Java bytecode files (*.class) to Java source files (*.java)

JD [decompile and analyze] (Freeware)
JODE [decompiler and optimizer] (open-source)
Mocha [early first decompiler] (Freeware)

The Java Platform



Numbers and Math

Data Types and Operators

Program Control Statements

Classes Objects and Methods

Data Types and Operators

Methods and Classes

Exception Handling



Mastery Check

Multithreaded Programming


serial ver

+API Quick Reference

java io

java lang

java math

java net

java nio and Subpackages

java security and Subpackages

Networking with java net


Permission Classes

JavaBeans Conventions

Development Tools

util and Subpackages


net and javax net ssl

security auth

javax xml

org w3c dom
org xml sax and Subpackages
Class Method and Field Index

External articles

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