Access File through multiple threads

Question

I want to access a large file (file size may vary from 30 MB to 1 GB) through 10 threads and then process each line in the file and write them to another file through 10 threads

Answer 1

Spring Batch comes to mind.

Maintaining the order would require a post process step i.e Store the read index/key ordered in the processing context.The processing logic should store the processed information in context as well.Once processing is done you can then post process the list and write to file.

Beware of OOM issues though.