Oracle developer needs Java help

Question

I develop applications in Oracle 8i on NT4. As part of a trigger, I need to perform an update to an extremely large table which takes many minutes. Because it's tied to a web page, I can't wait for the update to complete. Oracle natively doesn't support system calls -- I use the Shell() command in VB -- but Oracle DOES support Java stored procedures. I'm hoping that a Java stored procedure will be able to spawn/execute a new process/program specified by a command line instruction (ie: "C:\SQLPLUS.EXE SCOTT/TIGER @update.sql") and return immediately - without waiting for the process to complete. There doesn't need to be any handle for or call back from the process - just fire and forget. Can anyone provide me some direction, or better some existing Java code that does this? THANKS!

Answer 1

Hi "todmcg",
I'm not sure that I have understood your question correctly, but here goes anyway...
Yes you can create a java stored procedure and have a trigger execute that procedure. In order to execute system commands in java, you usually use the "exec()" method of class "java.lang.Runtime". It is also easy to spawn new threads using java. So yes, you can have your java stored procedure execute a system command in a background thread.
In my opinion, the Oracle documentation explains very well how to create a java stored procedure. The documentation is available from:
http://tahiti.oracle.com
Also, examples of how to call system commands from java stored procedures are available at this Web site:
http://asktom.oracle.com
You may also find relevant information at:
http://metalink.oracle.com
and
http://technet.oracle.com
Of-course, you can also use JDBC from your java stored procedure to execute your "update.sql" script -- without the need to execute a system command.
Basic code skeleton:
[NOTE: Untested and may contain syntax errors.]
public class SystemCommand implements Runnable {
  private static String cmd;
  public void run() {
    Runtime runtime = Runtime.getRuntime();
    runtime.exec(cmd);
  public static void execCommand(String cmd) {
    this.cmd = cmd;
    new Thread(new SystemCommand()).start();
}Hope this helps you.
Good Luck,
Avi.