By: Jatin Chawla

Java environment contains a rich set of development tools & thousands of classes and methods. It has mainly two parts:

• 1. Java Development Kit(JDK)
• 2. Java Standard Library(JSL)

Java Development Kit (JDK)

The Java Development Kit is a software package that is provided by the "SUN Microsystem" to public for free of cost. Java Development kit is currently available for most operating systems. It comes with a large collection of rules that are used for developing & running Java programs. It includes all the basic components that makeup the Java Environment. It also includes Utilities documentation and sample code for developing Java Programs. The Java Development Kit(Jdk) contains files and directories that are required to develop Java Applications after installing Java. Some Directories are following:
BIN, INCLUDE, JRE, LIB, DEMO etc.

There are following Java development tools that are used to create programs and applications.

The Java Applet Viewer

It enable us to run Java applets on Appletviewer window. The executable code name is "appletviewer" . It is basically used to execute applets without Java enabled Web Browser.

e.g. appletviewer myapplet.java

The Java Interpreter

This tool enable us to run Java applets and applications by reading and interprating bytecode files. The executable code name is "java".

e.g. java myfile

The Java Compiler

This tool enable us to compile java source code (program) into bytecode. The executable code name is "javac".

e.g. javac myprogram.java

The Java API documentation generator

This tool Creates API documentation in HTML format from Java source code. The executable code name is "javadoc".

e.g. javadoc document.java

The Java header and stub file generator

It Creates C-language header and stub files from a Java class, which allows your Java and C code to interact. It provides header files for use with native method. The executable code name is "javah".

The Java class file Decompiler / Deconstruct

It Disassembles Java files and prints out a representation of Java bytecode. It enables us to convert byte code files into a program description. The executable code name is "javad".

The Java language debugger

This tool helps us to find and fix errors in our program. The executable code name is "jdb".

Java Standard Library(JSL)

It is also known as Java Application Program Interface. The main and essential part of a human body is Heart; Same like this The main part (heart) of any programming language is Package. It includes hundreds of classes and methods grouped into Several functioned package. These packages provide everything that we need to create a powerful application. There are following packages in Java Standard Library:

Langauage Support Package

It is the core set of classes for the Java language that provide basic functions, such as string and array handling. This collection of classes and methods required for implementating basic features of Java.


Package Name: "java.lang"

Utility Package

It is the collection of classes to provide utility function such as date and time function, encoding/decoding, hash tables, and stacks.

Package Name:"java.util"

Input / Output Package

A set of classes provide the standard input / outputs and file I / O manipulation.

Package Name: "java.io"

Network Package

A set of classes that provide tools for accessing / communicating with other networks by protocols, such as FTP, Telnet, and HTTP (Internet Means).

Package Name: "java.net"

AWT Package

AWT (Abstract Window Toolkit) Package contains classes that implements platform independent graphical user interface such as buttons, labels, frames etc.

Package Name: "java.awt".

It also include other package like "java.awt.image", "java.awt.peer" etc.

Applet Package

This includes a set of classes that allows us to create java applets; This relate to the applet environment and are generally used when viewing applets.

Package Name: "java.applet"

SQL Package

It enables us to create and develop java application that access database.

Package Name: "java.sql"