Q: I’ve been asked to extend my company’s Java-based spreadsheet software to read and write Excel spreadsheets. Can you recommend an open source Java library that will help me with this task?

The Java input/output (I/O) facilities provide a simple, standardized API for reading and writing character and byte data from various data sources. This article explores the I/O classes ...

Another option for writing an Excel file is to write the output in CSV (comma-separated value) format. You can also read a CSV file from a Java application.