Scheduled & Triggered Jobs

Question

I have a Visual Basic console application that runs other Visual Basic back-end applications on a scheduled and triggered basis. I have a list of scheduled and triggered entries in a database that this console application will read upon starting up. The application runs the VB programs at scheduled times and simultaneously runs VB programs when the correct trigger files are present.
I want to port the applications over to Java 1.3/1.4. I'm very proficient in both Visual Basic and Java. Unfortunately, the operating system I am running is Windows 2000 :(
My idea is to have a Java application (which runs 24x7) that will run programs and/or threads to handle data processing (i.e. importing a text file into a relational database). We also are running Websphere Application Server 4.0 and I haven't found anything built into Websphere that will do this.
Questions:
How would I handle the following in Java:
1) At a particular time of the day, how could I schedule a java program and/or thread from a Java application?
2) How would I periodically check for trigger files (i.e. on a network share) within a Java application?
These (batch job) programs normally perform one of these functions:
1) Read a file received and import the file into a database table.
2) Export database records into a file and ftp the file off to a remote server.
All this would need to be done simultaneously. I have several good ideas on how to create this, but I wanted to get the advice of experts to see how they would attack these issues.
Please respond.
Bill

Answer 1

Bill,
It is possible that I do not fully understand the problem that you are trying to solve, but from what I read I can provide some suggestions:
1) At a particular time of the day, how could I schedule a java program and/or thread from a Java application?
You could write a timer class that fires off events at certain times of the day. These events would be picked up by a listener which would in turn create a thread to execute the necessary functions. When the functions are complete, the thread dies. Since you are writing data files be sure to synchronize the writing incase multiple threads attempt to write the data simultaneously.
2) How would I periodically check for trigger files (i.e. on a network share) within a Java application?
Again, this is a threading issue. Spin up a thread to periodically check if a file has come into existence since the last check. Here is a piece of code that can do the check:
long time = rightNow.getTime(); //setting the time
try { Thread.sleep(1000); } catch(Exception e) { } //waiting a period of time
if (file.exists() && file.lastModified() > time) //checking if a file has changed
time = file.lastModified();