Java in Oracle

CREATE OR REPLACE AND COMPILE JAVA SOURCE NAMED "Hello" AS
public class Hello
{
public static String World()
{
return "Hello World!";
}
};
/

CREATE OR REPLACE FUNCTION helloworld
RETURN VARCHAR2
AS
LANGUAGE JAVA
NAME 'Hello.World () return java.lang.String';
/

drop function helloworld

DECLARE
v_string VARCHAR2 (100 CHAR);
BEGIN
v_string := helloworld ();
dbms_output.put_line('v_string'||v_string);
END;
/

SELECT helloworld FROM DUAL;