Springboot MCPserver JUnit

🚀 Springboot + MCP + JUnit Project Template

This project template uses Springboot to quickly build an MCP project, and it supports JUnit unit tests. It supports two modes: STDIO and SSE.

🚀 Quick Start

Development Environment

• Development IDE: IDEA
• Java Version: JAVA17 (Spring officially requires Java17 or higher)
• Maven Version: 3.8.1 (A higher version may cause errors when importing the project. Please choose an appropriate version)

Reference Documents

1. MCP Official Website - Protocol (Required reading)
2. MCP Official Website - Coding Guide
3. Spring Official Website

Client Testing Solutions

1. Configuration for STDIO Client

Command:
    java
Arguments:
    -jar
    -Dfile.encoding=UTF-8
    -Dspring.ai.mcp.server.stdio=true
    AbsolutePath/**/xxx.jar
Environments:
    env1=xxx
    env2=yyy

• The command is java (If the local main environment is not Java17 or higher, please switch).
• The parameter file.encoding specifies the encoding of System.in and System.out to UTF-8 to avoid encoding issues.
• The parameter spring.ai.mcp.server.stdio indicates that the service is enabled in STDIO mode.
• The environment configuration writes the configuration into the current system environment for the current program to access.

2. Configuration for SSE Client

Just fill in the following link for the SSE address:
http://HostAddress:Port/sse

✨ Features

Exploration of Additional Optional Features

1. Modify the Message Endpoint

Refer to the configuration file McpServerProperties.

spring.ai.mcp.server.sseMessageEndpoint=/mcp/message

2. Modify the SSE Endpoint

The original SSE endpoint is /sse, and the configuration file does not provide a way to configure the SSE endpoint. So, you need to re - inject ServerMcpTransport to replace the original one.

Note that both of the following Bean configurations need to be added. In the auto - injection file MpcWebMvcServerAutoConfiguration, the injection condition for the entire registration is @ConditionalOnMissingBean(ServerMcpTransport.class), which causes both of the following beans not to be injected.

private final String SSE_ENDPOINT = "/sse";

@Bean
@ConditionalOnMissingBean
public WebMvcSseServerTransport webMvcSseServerTransport(ObjectMapper objectMapper,
        McpServerProperties serverProperties) {
    return new WebMvcSseServerTransport(objectMapper, serverProperties.getSseMessageEndpoint(), SSE_ENDPOINT);
}

@Bean
public RouterFunction<ServerResponse> mvcMcpRouterFunction(WebMvcSseServerTransport transport) {
    return transport.getRouterFunction();
}

3. Multiple Endpoints for One Service?

You need to re - inject multiple McpSyncServer. See the class MpcServerAutoConfiguration for details.

Since multiple endpoints may involve many things, those who are interested can study it by themselves. I only provide such guidance!

4. SSE Authorization?

In the MCP official protocol document on March 26, 2025, the authentication scheme was updated. We are looking forward to the update of Spring.

📚 Documentation

Explanation Videos

• First release全网首发: Build a Springboot + MCP + JUnit project from scratch BV1qUXkYRE6C
• First release全网首发: From building to going live with Springboot + MCP(SSE) + JUnit BV1rSXWYGEVz