Java静态方法用作Oracle函数

Question

I'm quite new to Java development and Oracle either, but I'm learning.

My problem is the following, I created a dll in .net and used it as custom function in MSSqlServer, basically this library act as a SOAP gateway letting me call a webservice (both in GET and POST) simply using a SELECT like this

SELECT * 
FROM fn_SoapGateway_MakeWebRequest
(
'GET', -- Method
'https://fish.go-moo.it', -- Url
'/foo/bar?method=info', -- Path
'' -- XML Envelope
)

Now, I want to do the same thing but using Java for Oracle. For testing purposes, I created the class "SoapGateway" which exposes two static methods:

• 1) public statis String GetData() <- which returns just a string, to see that all things work good..

• 2) public static String MakeWebRequest(String username, String password, String method, String url, String path, String envelope) <- makes the call to the webservice

The second step is compiling everything with the Oracle java compiler so there will be no problems of java version: done!

Now third step: binding Oracle function to the java class with a simple code like this

CREATE OR REPLACE FUNCTION fn_SoapGateway_GetData RETURN VARCHAR2 AS LANGUAGE JAVA NAME 'SoapGateway.GetData() return java.lang.String'; COMMIT;

and last, test the simple function GetData with this select

SELECT MY_SCHEMA.fn_SoapGateway_GetData() FROM DUAL ;  

works like a charme!! and it returns me my custom string.

Now, finally I can ask you my questions:

1) What should I write in Oracle to bind the function "MakeWebRequest" and create the function in Oracle?

2) Is it correct sending a "String" as an Envelope and returning a "String" or should I use a bigger data type? If so, which kind of data type? Can you help me correcting my code? I can share everything once it works

3) How can I invoke the function correctly from Oracle to obtain the response as an XML variable?

Many many thanks for helping! tell me if I was not clear in something! ((:

----------------------- UPDATEEEEE -----------------------------

Ok guys, now step 2.0.. I obtained the result I wanted from Java, I used java.sql.Clob and everything seems fine..

So, I tested from a main in eclipse, called the SoapGateway.MakeWebRequest(.....) and everything seems perfect! The remote host replies with the xml for my Get method. --> ok

Now, I loaded the java class into oracle server with loadjava -schema bla bla bla --> ok

Then, compiled it from the Enterprise Manager --> ok

Then, created a function like this

CREATE OR REPLACE FUNCTION fn_SoapGateway_MakeWebRequest(v_username VARCHAR2, v_password VARCHAR2, v_method VARCHAR2, v_url VARCHAR2, v_path VARCHAR2, v_envelope VARCHAR2) RETURN CLOB
AS LANGUAGE JAVA NAME 'SoapGateway.MakeWebRequest_Clob(java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String) return java.sql.Clob';

COMMIT;

--> ok!

And finally.. called it with:

SELECT MY_SCHEMA.FN_SOAPGATEWAY_MAKEWEBREQUEST
(
    'user',
    'pass',
    'method',
    'url',
    'path',
    'envelope',
) FROM DUAL;

ORA-29532: Chiamata java terminata a causa di un'eccezione Java non ottenuta: java.lang.NullPointerException (Java call terminated for null pointer exception) --> KO!!

Now, any idea about why on Eclipse works like a charme and from Oracle it generates such error? Am I doing something wrong?

Thank you so much!

L.

Answer 1

ad 1) Something like that should work:

CREATE OR REPLACE FUNCTION yourFunctionName(username  varchar2, password varchar2, method varchar2, url varchar2, path varchar2, envelope  varchar2) RETURN VARCHAR2 AS 
LANGUAGE JAVA NAME 'SoapGateway.MakeWebRequest(java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String) return java.lang.String';

ad 2) If data is big, you can use BLOB - it's working perfectly for me when I'm generating xml ;)

ad 3) Try this:

SELECT yourFunctionName('username', 'pass', 'method', 'url', 'path', 'envelope') FROM dual;