1. LECTURE 04 JAVA DEVELOPMENT KIT

2. (Java Development Kit) A Java software development environment from Sun. It includes the JVM, compiler, debugger and other tools for developing Java applets and applications. When Java programs are developed under the new version, the Java interpreter (Java Virtual Machine) that executes them must also be updated to that same version. JAVA DEVELOPMENT KIT (JDK)

3. The JDK has as its primary components a collection of programming tools, including: The Java Compiler , ‘javac’ the compiler, which converts source code into Java bytecode. Syntax: javac sourcecodename.java The Java Interpreter, ‘java’ the loader for Java applications. This tool is an interpreter and can interpret the class files generated by the javac compiler. Syntax: java sourcecodename JDK Tools

4. The Java Dissembler, ‘javap’ The javap command dissembles Java bytecode that has already been compiled. After dissembling the code, it prints the information about the member variables and methods of class. Syntax: javap classname The Documentation Tool, ‘javadoc’ the documentation generator, which automatically generates documentation from source code comments. Its creates a HTML file based on tags. These HTML files store information about the class and methods in a program. Syntax: javadoc sourcecodename JDK Tools Cont…

5. The Java Debugger, ‘jdb’ This is a debugging tool for the java environment. It is typically used to find out syntactical and logical errors. Syntax: jdb sourcecodename //if code is present on the local machine. jdb host-password sourcecodename // if code is on a remote machine The appletviewer, ‘appletviewer’ this tool can be used to run and debug Java applets without a web browser. Syntax: appletviewer url

6. API stands for “Application Programming Interface”. An API is the definition of how a programmer can access the functionality contained within a code library. Java comes with many code libraries that provide pre-written functionality for programmers. Some of the most commonly referred packages are: java.lang: the java.lang package consists of classes that are at the core of java language. These include the basic datatypes, such as int, char etc. it also include classes that handle exceptions and errors. The System class that facilitates the standard input, output, and errors output streams also define in this package. Java.applet: the java.applet package is the smallest package. It consists a single class called Applet class. This class must be the parent class of any applet application. Java Core API

7. java.awt: This package is also called Abstract Window Toolkit. It consists resources to create GUI- based applications. java.io: This package provides the standard Input/output library for the java language. java.util: This package provides a number of useful utilities classes. The classes in this package include Date, Stack, Vector etc. Java.net: This package provides the capabilities to communicates with remote machine. It creates or connects to sockets, or to URLs. Java.awt.event: This package is useful in calling the event listeners, and to use events any way you want. A listener is an object that is notified when an event occur. Java.sql: This package encompasses the JDBC, or Java DataBase Connectivety. JDBC allows you to access relational database like Oracle and Ms-SQL server. java.swing: A new set of classes and interfaces used to create an advance GUI.

8. The Development environment is divided into two parts: a Java Compiler, a Java interpreter. Unlike C and C++, the Java Compiler converts the source code into bytecodes, which are machine independent. Bytecode are chunks of java instructions broken down into bytes, which can be decoded by any processor. The Java Interpreter is also called the JVM (Java Virtual Machine), or Java Runtime interpreter. It executes the Java Bytecodes. Java has become such a universal language, that soon every operating system will be equipped with the Java Virtual Machine. JAVA DEVELOPMENT ENVIRONMENT

10. The Java Runtime Environment (JRE), also known as Java Runtime, is part of the Java Development Kit (JDK), a set of programming tools for developing Java applications. The Java Runtime Environment provides the minimum requirements for executing a Java application; it consists of the Java Virtual Machine (JVM), core classes, and supporting files. JAVA RUNTIME ENVIRONMENT