Modernize Java with Cursor and GitLab

This post details the integration of Cursor, an AI coding agent, with GitLab's Duo Agent Platform and Model Context Protocol (MCP) to modernize a Java application. It demonstrates how to use Cursor for focused tasks like fixing failing tests and preparing for larger migrations, while leveraging GitLab's issue hierarchy, CI/CD, and code review workflows to ensure the safety and reviewability of AI-generated changes. The post outlines three use cases: fixing a failing end-to-end test, preparing quality gates for Java 8 to 21 modernization by ensuring CI/CD tests both versions in parallel, and modernizing HTTP connection handling. It highlights the use of the GitLab MCP server to bring project context into Cursor and the importance of GitLab's Duo Agent Platform flows (Code Review, Developer Flow, impact analysis) for certifying AI-generated code.