Hi Noor, I've used java with Crystal Reports for one of my reporting modules. I don't think Crystal reports can directly interface with java program. how we did it is as follows. -- Crystal Reports provides API for C++. -- So we created a C++ program that uses those API to generate a report. -- and since we can execute an exe from java so we called the above mentioned C++ exe from our java front end. But let me tell you one thing that later on we found out that this combination java - c++ - crystal reports was very slow for huge amount of data. It was considerably slow when we tested it for 200,000 records. so when it came to our next module we tried to find out some alternate to Crystal Reports. Presently we are generating Tabular Reports using html while for graphical ones we are using JClass from KLGroup.KlGroup also have some classes for tabular report generation but we r not using it. the best thing i'll suggest u to go to http://www.google.com and search for reporting tools for java or similar.
hope this long post of mine was of some help to u.