HEMANT SONKER'S BLOG: Running a Java Program from Command Prompt

Create a temporary folder C:\mywork. Using Notepad or another text editor, create a small Java file Hello.java with the following text:
```
 class Hello
{
public static void main(String[] args)
{
System.out.println("Hello, World!");
}
}
```
Save your file as Hello.java in C:\mywork. To make sure your file name is Hello.java, (not Hello.java.txt), first choose "Save as file type:" All files, then type in the file name Hello.java.
Run Command Prompt (found under All Programs/Accessories in the Start menu). Type
```
C:\> cd \javaprog
```
This makes C:\mywork the current directory.
```
C:\javaprog> dir
```
This displays the directory contents. You should see HelloWorld.java among the files.
```
C:\javaprog> set path=%path%;C:\Program Files\Java\jdk1.5.0_09\bin
```
This tells the system where to find JDK programs.
```
C:\javaprog> javac Hello.java
```
This runs javac.exe, the compiler. You should see nothing but the next system prompt...
```
C:\javaprog> dir
```
javac has created the Hello.class file. You should see Hello.java and HelloWorld.class among the files.
```
C:\javaprog> java Hello
```
This runs the Java interpreter. You should see the program output:
```
Hello, World!
```
If the system cannot find javac, check the set path command. If javac runs but you get errors, check your Java text. If the program compiles but you get an exception, check the spelling and capitalization in the file name and the class name and the java Hello command. Java is case-sensitive!
It is possible to make the path setting permanent but you have to be very careful because your system might crash if you make a mistake.