• Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint
Share this Page URL
Help

Chapter 10. Running Java Applications > Java on the Command Line

10.4. Java on the Command Line

You can run Java programs from the command line through the java command. Generally, you invoke it in one of two ways:


java options class argument1 argument2...

Loads the specified class and runs its main method. If it has no such method, or if it's of the wrong format,[2] then the class will fail to launch.

[2] To be invokable like this, a Java class's main method must have the signature public static void main(String[ ] args).

You should have a class path defined so that the Java interpreter will know where on the filesystem to search for the specified class. See Section 10.4.1.


java options -jar jarfile arguments

In this case, the -jar option tells the Java interpreter to launch a program encapsulated in a Jar (Java Archive) file.[3] This works only if the Jar file knows its own Main-class, which defines the main method.

[3] Jar files are created through the jar utility, one of several standard Java tools that come with Mac OS X; see Chapter 25.

Jar files, like Mac OS X applications, are self-contained and ignore the user's class path definitions.

This section involves using the Terminal. If you are completely unfamiliar with this application, or with using a Unix command line in general, you may want to skip ahead to Chapter 19 first.



PREVIEW

                                                                          

Not a subscriber?

Start A Free Trial


  
  • Creative Edge
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint