Programming in Java I

Running a Java Program From the command prompt

I suggest using Textpad to edit your Java source code.

• Create a directory (folder) on your root drive (typically the C drive) named csc211.
• Using an editor such as Textpad enter in the Welcome program discussed in class.
• Save as Welcome.java to directory csc211.
• It is a coding standard to make all java classes begin with uppercase. You must follow that standard. Since the name of the class begins with uppercase your file name must begin with uppercase. The filename name must be identical (in case) to the class name.
• Go to the command prompt: (For windows)
• Click the start button
• Select run
• Enter cmd or command (depending on your OS) in the combo box labeled open.
• You should now see the terminal window. You may see something similar to this at the bottom of the window.

 C:\Documents and Settings\Administrator>
 

• Need to navigate to the directory csc211.

• Some DOS commands

            cd .. takes you back one directory (do this until you reach the root on my computer that would
                  be the C drive )
            cd \ takes you to the root.
            cd csc211 (changes to directory csc211)
            dir /p (displays names of sub directories / files )
          

• In my case I would type in ..

  cd \
  cd csc211
  

• The prompt should now look like this.

  C:\csc211>
  

• Once you are in directory csc211 you will need to access the Java compiler.
• Enter this command:

  javac Welcome.java
  

javac is the name of the compiler. If all goes well, you should see a file named Welcome.class in the csc211 directory

• Type the command to see the .class file

   dir /p
   

If this does not compile, check your syntax. If the syntax is ok and you see a message similar to

	  bad command  or javac is not  recognized
	

You will have to set your PATH variable. You cannot continue until your path variable is set properly. See Java Setup at the resource page.
• If you're program compiled now you have to run it. At the command prompt enter.

  	java Welcome
  	

• If you see the message you are done.
• If you are able to compile your program but not execute, that is after you enter the above command

  	java Welcome
  	

  You see something similar to :

  	Exception in thread main ........
  	

  You will have to update your classpath. See setting classpath at the resource section. For now try entering the command.

  	java -cp . Welcome
  	

  Notice the dot '.'