How To Call a JAVA Program from PL/SQL?

Step1: Create the JAVA Class ( Here Factorial.java )

public class Factorial
{

public static int calcFactorial(int n)
{
if(n==1)
return 1;
else
return n * calcFactorial(n-1);
}

}


Step2: Load the JAVA Class into the DB ( Using the command prompt)
> loadjava -user scott/tiger@c920 E:\Factorial.java
Or
> loadjava -user scott/tiger@c920 E:\Factorial.class ( If it’s a class file)

Step3: Verify the Java source has been loaded or not by
SELECT *
FROM USER_OBJECTS
WHERE OBJECT_TYPE LIKE ‘JAVA%’;
You Could see the source code by
SELECT text
FROM USER_SOURCE
WHERE NAME=’ Factorial’;

Step4 : Create a Procedure or Function that could call the JAVA method

CREATE OR REPLACE FUNCTION calc_fact( p_no NUMBER)
RETURN NUMBER
AS
LANGUAGE JAVA
NAME ‘Factorial. calcFactorial (int) return int’ ;