A Java Stored Procedure

/* The Java method 'greetings' will takes a String argument and returns a string value. This method requires to be published in SQL */

Java Class Welcomejava:
Public class welcome {
Static public String
Greetings (string firstname) {
 Return "Welcome" + firstname;
}
}

/* PL/SQL proxy for welcomejava
It maps the string datatype to SQL VARCHAR2 */

CREATE FUNCTION greetings (fname VARCHAR2) RETURN
VARCHAR2 AS
LANGUAGE JAVA NAME
'Welcome.greetings (Java.lang.String)
return Java.lang.String'

Java methods which are called by SQL or PL/SQL execute under definer's privileges. A Java methods called from other Java methods can execute under definer's or invoker's privileges, but by default, it execute under the invoker’s privileges.  This will marked difference from execution of PL/SQL procedures which execute under the definer's privileges. In sequence to execute a Java method, users must have the subsequent privileges:

•    EXECUTE rights on the call descriptor of PL/SQL for the Java method
•    EXECUTE rights on the Java class
•    EXECUTE rights on the Java classes and resources used through the Java class being called.