Always close your Workbook and OutputStream to prevent memory leaks.
To make the browser "download" the file instead of trying to display it as text, you must set specific headers in your Servlet or Spring Controller.
To create Excel files ( .xls or .xlsx ) in Java, you don't want to build the XML structure manually. Use an established library: download excel file in browser using java
This guide covers everything from choosing the right libraries to handling the HTTP response headers that trigger a browser download. 1. Choose Your Java Library
The attachment value tells the browser to open the "Save As" dialog. 5. Implementation (Spring Boot Example) Always close your Workbook and OutputStream to prevent
Better choices if you are dealing with massive datasets (hundreds of thousands of rows) to avoid OutOfMemoryError .
For most projects, is the best balance of features and community support. 2. Set Up Your Dependencies Add the following to your pom.xml if you are using Maven: Use an established library: This guide covers everything
An older, lighter alternative, but lacks support for .xlsx .