How to call the main method

You typically start Java applications (outside the database) by running the Java VM on a class that has a main method.

For example, the Invoice class in the file %SQLANYSAMP16%\SQLAnywhere\JavaInvoice\Invoice.java has a main method. When you execute the class from the command line using a command such as the following, it is the main method that executes.

java Invoice

Calling the main method of a class from SQL

Perform the following steps to call the main method of a class written in Java:

Declare the Java main method with an array of strings as an argument:

public static void main( java.lang.String args[] )
{
...
}

Create a stored procedure that wraps this method.

CREATE PROCEDURE JavaMain( IN arg CHAR(50) )
EXTERNAL NAME 'JavaClass.main([Ljava/lang/String;)V'
LANGUAGE JAVA;

Invoke the main method using the SQL CALL statement.
CALL JavaMain( 'Hello world' );
Due to the limitations of the SQL language, only a single string can be passed.

How to call the main method

Calling the main method of a class from SQL

See also