Supplements
Scope
Debug Techniques
Java Runtime
Class Class
JVM Instructions 2
JVM Processing
pack200

The JRE (Java Runtime Environment) refers to those essential elements (executables, class packages, and other resources) needed to run Java applications and applets. For example, when you distribute your application to users, you must insure that they have at least the JRE installed so that they can run the program.

You installed the JDK - Java Development Kit (or SDK - Standard Development Kit), which provides the JRE and also various tools like a compiler, appletviewer, and so forth to do program development.

When you distribute your program you might simply ask your users to download the JRE and install it themselves if you expect them to be proficient computer types. Otherwise, you will need to use an automatic installer that does most of the work for them.

Note that the JRE for Windows includes the javaw executable that performs exactly like the java program except that it does not use a console window; that is, like normal Windows programs. For example, to run from a click a shortcut icon, just create a bat file with lines like the following

@echo off
@start C:\J2RE1.4.0\bin\javaw MyApplication

and attach the bat file to the shortcut icon by opening the icon's properties dialog.

References & Web Resources

1. SDK and JRE at java.sun.com
2. java - the Java Application Launcher at java.sun.com

            Tech
DecimalFormat
  Demo 1
  Demo 2
System.out.printf
  Demo 3
CJ Format Class
  Demo 4   Demo 5
Other Format Tools
Immutable Complex
Exercises

           Physics
Interpolation
Integration
  Demo 1
Simpson Rule
  Demo 2
Exercises