Execution Control

In Sun Microsystems's JDK environment, you develop Java applications with a main() method, which is called by the interpreter when the class is run. The main() method is invoked when you execute java <classname> on the command-line. This command starts the java interpreter and passes the desired classname to be executed to the interpreter. The java interpreter loads the class and starts the execution by invoking main(). However, Java applications within the database do not start their execution from a main() method.

After loading your Java application within the database (see "Loading Classes"), you can execute your Java code by invoking any static method within the loaded class. The class or methods must be published for you to execute them (see "Publishing"). Your only entry point is no longer always assumed to be main(). Instead, when you execute your Java application, you specify a method name within the loaded class as your entry point.

For example, in a normal Java environment, you would start up the Java object on the server by executing the following:

java myprogram

where myprogram is the name of a class that contains a main() method. In myprogram, main() immediately calls mymethod for processing incoming information.

In Oracle8i, you load the myprogram.class file into the database and publish mymethod as an entry-point. Then, the client or trigger can invoke mymethod explicitly.

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