Java EE Platform

Java is a programming language. The Java EE Platform provides a runtime environment (also known as JRE or Java Runtime Environment) as well as a development kit (also known as JDK or Java Development Kit) for building applications in Java. There are a few variants of the platform:

• Java Platform, Standard Edition (Java SE) is the core of Java technology used mostly for application development. The runtime environment is widely used in Web browsers to run small applications known as applets. The development kit is used to compile and deploy Java applications or applets and is usually embedded in integrated development environment (IDE) tools.

• Java Platform, Micro Edition (Java ME) is a lightweight and trimmed down version of the Java SE. It is designed for mobile devices such as cellular phones.

• Java Platform, Enterprise Edition (Java EE) builds on top of Java SE and adds many features that can build Web-based objects (such as servlets) and reliable enterprise applications (such as Enterprise Java Beans). Java EE is run on an application server. The next section contains many details on its architecture.

For example, you can create a simple Java program MyInteropSample.java using a text editor that prints out the simple message, "This is a simple Java application," as follows:

public class MyInteropSample {     // define your variables here…     public static void main(String args[]) {         // you can insert your processing logic here…         System.out.println            ("Java EE .NET Interoperability Sample");         ...     } } 

This simple Java application has a structure

public class <program name> { ...}

followed by the variables and processing logic or methods used in the program. The main() method defines the processing logic when the program starts. In this example, the main() method prints out a text message.

For more information on getting started with Java, please refer to http://java.sun.com/docs/books/tutorial/index.html. The rest of this book assumes prior knowledge of Java.

To compile the Java program, use the command javac as follows:

%javac MyInteropSample.java

To run the Java application, use the command java as follows:

%java MyInteropSample