Re: Java stored procedures questions

A copy of this was sent to "Alex Murkes" <murkes_at_my-Deja.com> (if that email address didn't require changing) On Mon, 23 Aug 1999 15:37:05 -0700, you wrote:

>I have some questions regarding Oracle stored procedures written in Java.
>
>Here's a very simple test Java class i'm trying to load into the RDBMS:
>
>public class SPTest
>{
> static int num = 0;
>
> public static int getInt()
> {
> return num++;
> }
>}
>
>1) I get this error:
>$ loadjava -user <connect_string> SPTest.class
>Error while retrieving errors for SPTest
> ORA-00904: invalid column name
>
>loadjava: 1 errors
>
>Anyone know what's wrong? In something configured incorrectly?
>
loadjava is the script that fails, the SQL it performs is: select dbms_java.shortname('hello/Hello') from dual; The reason it returns ora-904 invalid column name is because the dbms_java package wasn't run. You need to run javavm/install/initjvm.sql after this you can load java into database.

This should have been installed if you selected the java server option when you created the database.

>2) Will Oracle "do the right thing" with the stored procedure above? In
>other words, is there persistency, do static variables keep their values
>across procedure invocations? Or does Oracle reload classes on every call
>to stored procedures?
>

the classes stay there, for example:

tkyte_at_8i> create or replace function GetInt return number   2 as language java
  3 name 'SPTest.getInt() return int';
  4 /

Function created.

tkyte_at_8i> select getint from all_users where rownum < 10;

    GETINT

         0
         1
         2
         3
         4
         5
         6
         7
         8

9 rows selected.

tkyte_at_8i> select getint from all_users where rownum < 10;

    GETINT

         9
        10
        11
        12
        13
        14
        15
        16
        17

9 rows selected.

tkyte_at_8i>
tkyte_at_8i> disconnect
Disconnected from Oracle8i Enterprise Edition Release 8.1.5.0.0 - Production With the Partitioning and Java options
PL/SQL Release 8.1.5.0.0 - Production
tkyte_at_8i> connect tkyte/tkyte
Connected.
tkyte_at_8i>
tkyte_at_8i> select getint from all_users where rownum < 10;

    GETINT

         0
         1
         2
         3
         4
         5
         6
         7
         8

9 rows selected.

>3) Assuming some persistency exists, does RMI work from Java stored
>procedures? Can I expose a persistent object to external processes through
>RMI?
>

cannot speak for RMI as i haven't used RMI but as sockets work just fine to achieve the above (i've done that) i don't see why not -- i just haven't tried it.

>Thanks!
>-Alex
>
>
>
>

-- 
See http://govt.us.oracle.com/~tkyte/ for my columns 'Digging-in to Oracle8i'...
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Thomas Kyte                   tkyte_at_us.oracle.com
Oracle Service Industries     Reston, VA   USA

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