Solon 4.0 ChatModel: A Practical Guide to Building LLM-Powered Applications

If you've ever tried integrating a large language model (LLM) into a Java application, you've probably written a lot of boilerplate: HTTP clients, JSON parsing, streaming handling, session management. Solon 4.0's ChatModel abstracts all of that away with a clean, builder-oriented API. In this guide, I'll walk through building real, working AI features using ChatModel — from a simple chat call to a streaming chatbot with conversation memory. 1. What Is ChatModel? ChatModel (package org.noear.solon.ai.chat ) is a unified LLM client in Solon's AI ecosystem. Instead of writing raw HTTP calls for different model providers, you use a single API that supports: Synchronous calls — one-shot request, full response Streaming calls — reactive streaming via Project Reactor ( Flux<ChatResponse> ) Tool/Function Calling — let the LLM invoke your Java methods Chat Sessions — automatic conversation memory Multi-modal messages — text, images, audio Dialect adaptation — works with OpenAI, Ollama, Anthropic, Gemini, DashScope, and more The best part? It uses a dialect pattern — you point it at any compatible LLM endpoint, and it adapts automatically. 2. Setting Up Add the dependency to your pom.xml (no parent POM needed — Solon works standalone): <dependency> <groupId> org.noear </groupId> <artifactId> solon-ai </artifactId> <version> ${solon.version} </version> </dependency> This pulls in all built-in dialects (OpenAI, Ollama, Gemini, Anthropic, DashScope). 3. Configuration 3.1 Via YAML (Recommended) solon.ai.chat : demo : apiUrl : " http://127.0.0.1:11434/api/chat" # Full URL, not baseUrl provider : " ollama" # Dialect identifier model : " llama3.2" # Model name headers : x-demo : " demo1" Then create a @Bean to get a ready-to-use ChatModel : import org.noear.solon.ai.chat.ChatConfig ; import org.noear.solon.ai.chat.ChatModel ; import org.noear.solon.annotation.Bean ; import org.noear.solon.annotation.Configuration ; import org.noear.solon.annotation.Inject ; @Configuration public cla