Hi,

The project I am working on requires a whole bunch of queries towards a database. In principle there are two types of queries I am using:

1. read from excel file, check for a couple of parameters and do a query for hits in the database. These hits are then registered as a series of custom classes. Any hit may (and most likely will) occur more than once so this part of the code checks and updates the occurrence in a custom list implementation that extends ArrayList.

2. for each hit found, do a detail query and parse the output, so that the classes created in (I) get detailed info.

I figured I would use multiple threads to optimize time-wise. However I can't really come up with a good way to solve the problem that occurs with the collection these items are stored in. To elaborate a little bit; throughout the execution objects are supposed to be modified by both (I) and (II).

I deliberately didn't c/p any code, as it would be big chunks of code to make any sense.. I hope it make some sense with the description above.

Thanks,