How to Run Java Applications using the Windows Command Prompt. Julian Falasca May 11 th, 2010 ENGL 393

Introduction Purpose: Most IS courses don’t touch this topic. Target Audience: Students already familiar with Java programming. (CMSC and IS majors) When to Use: On the job. Safety Information: Don’t get too excited.

Materials Needed At least 1 valid java source file. (HelloWorld.java) – Must know where this file is located. Java Development Kit (JDK) already installed. –

Step 1 Click on Start, Programs, Accessories, and select Command Prompt.

Example Command Prompt

Step 2 This example uses a java file which is located: D:\Workspace\HelloWorld.java Type d: and press enter. – This command changes directories to the D drive.

Example Command Prompt

Step 3 Type cd Workspace and press enter. – This takes you into the Workspace directory.

Example Command Prompt

Step 4 Type dir and press enter. This displays a list of files in the current directory. – Confirm that HelloWorld.java is in the list.

Example Command Prompt

Step 5 Type javac HelloWorld.java and press enter. – This compiles the file, allowing you to run it. A new file has been created named HelloWorld.class.

Example Command Prompt

Step 6 Type java HelloWorld and press enter. – The Java application will run.

Example Command Prompt

Conclusion Warranty Information: N/A Technical Support: Lookup commands on google. FAQs: – Why do I get the error “javac command not recognized”? Most likely you have not installed the JDK correctly. – How do I go to the previous directory? Type cd.. and press enter.

Conclusion Continued ProblemCauseSolution When compiling you get the following error: Class names, ‘HelloWorld’, are only accepted if annotation processing is explicitly requested. You typed javac HelloWorldYou must include the file extension when compiling. Type javac HelloWorld.java When running the application you get the following error: Exception in thread “main” java.lang.NoClassDefFound Error: HellowWorld/class You typed java HelloWorld.class You cannot include the extension when running. Type java HelloWorld

Questions?