Java
Java is a high-level programming language originally developed by Sun Microsystems and released in 1995. Java runs on a variety of platforms, such as Windows, Mac OS and various versions of UNIX. This tutorial gives a complete understanding of Java.
Java technology is a programming language and platform. The Java programming language is a high-level language. In the Java programming language, all source code is first written to plain text files ending with the .java extension.
These source files are compiled into class files by the javac compiler. A class file does not contain code that is native to your processor; Instead it contains byte-codes the machine language of the Java Virtual Machine (Java VM).
J2EE
J2EE is a platform-independent Java environment developed by Sun to develop, build and deploy web-based enterprise applications online. The J2EE platform consists of a set of services, APIs, and protocols that provide functionality for the development of multilevel Web-based applications.
Some of the main features and services of J2EE:
• At the client level, J2EE supports pure HTML as well as applets or Java applications. It is based on Java Server Pages and servlet code to create HTML or other formatted data for the client.
• Enterprise JavaBeans (EJBs) provide another layer where platform logic is stored. An EJB server provides functions such as threading, concurrency, security, and memory management. These services are transparent to the author.
• Java Database Connectivity (JDBC), which is the equivalent of Java to ODBC, is the standard interface for Java databases.
• The Java servlet API improves consistency for developers without the need for a graphical user interface.