Building a Production AI Agent in Spring Boot: Tools and Function Calling

tags: [java, springboot, ai, springai] Six months ago, I added an AI assistant to an e-commerce platform I was building. The idea was simple: let users type "show me orders with delayed shipping" or "what is the inventory level for wireless headphones?" and get real answers from live data. The first version worked. Barely. The model hallucinated order IDs, made up inventory numbers, and confidently claimed it could process refunds (it could not). The problem was not the LLM — it was that I had