MCP Server Java

A Model Context Protocol (MCP) server implementation in Java, demonstrating the core MCP features including tools, resources, and prompts.

Features

This MCP server provides:

Tools

• add: Add two numbers together
• multiply: Multiply two numbers
• get_current_time: Get the current server time
• greet: Greet a person by name
• ai_chat: Send prompts to Azure AI Foundry agent and get AI-powered responses

Resources

• server-info: Information about the MCP server
• documentation: Server documentation and usage examples

Prompts

• math_helper: Get help with mathematical calculations
• current_time: Get the current time

Prerequisites

• Java 17 or higher
• Maven 3.6+

Building the Server

Build the project using Maven:

mvn clean package

This will create an executable JAR file: target/mcp-server-java-1.0.0.jar

Running the Server

Run the server directly:

Export the Azure OpenAI API Key in Powershell : $env:AZURE_OPENAI_API_KEY="XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
Check that the environment variable is set c:>echo $env:AZURE_OPENAI_API_KEY

🚀 Usage

Start HTTP Server:

java -jar target/mcp-server-java-1.0.0.jar --http

java -jar target/mcp-server-java-1.0.0.jar 

Run Java Server:

Working Solution Step 1: Start the HTTP Server (in one terminal) java -jar target/mcp-server-java-1.0.0.jar --http (need http server to be running first)

Run Java Client:

Step 2: Run the Java Client (in another terminal) mvn exec:java "-Dexec.mainClass=com.example.mcp.client.McpJavaClient"

NPX Node Package eXecute

nxp command to test over web page

npx @modelcontextprotocol/inspector java -jar target/mcp-server-java-1.0.0.jar create a npx test harness to check out and test the functionality !

Testing out the tools :

HTTP JSON API Server started successfully! API Endpoints: http://localhost:8080/tools - List available tools http://localhost:8080/tools/add - Add two numbers http://localhost:8080/tools/multiply - Multiply two numbers http://localhost:8080/tools/time - Get current time http://localhost:8080/tools/greet - Greet by name http://localhost:8080/tools/ai_chat - Chat with AI agent

List all tools

curl -X GET http://localhost:8080/tools

Add two numbers

curl -X POST http://localhost:8080/tools/add -H "Content-Type: application/json" -d '{"a":"7","b":"51"}'

Multiply two numbers

curl -X POST http://localhost:8080/tools/multiply -H "Content-Type: application/json" -d '{"x":"7","y":"70"}'

Get current time

curl -X GET http://localhost:8080/tools/time

Greet someone

curl -X POST http://localhost:8080/tools/greet -H "Content-Type: application/json" -d '{"name":"Steve"}'

Chat with AI Agent

curl -X POST http://localhost:8080/tools/ai_chat -H "Content-Type: application/json" -d '{"prompt": "What is Azure AI Foundry?"}'

curl -X POST http://localhost:8080/tools/ai_chat -H "Content-Type: application/json" -d '{"prompt": "Hello"}'

Chat with AI Agent with Optional Parameters

curl -X POST http://localhost:8080/tools/ai_chat -H "Content-Type: application/json" -d '{"prompt": "Explain Model Context Protocol in simple terms", "max_tokens": 200, "temperature": 0.5 }'

curl -X POST http://localhost:8080/tools/ai_chat -H "Content-Type: application/json" -d '{"prompt": "Write a haiku about coding", "max_tokens": 200, "temperature": 0.5 }'

🚀 Usage

Start HTTP Server:

java -jar target/mcp-server-java-1.0.0.jar --http

Start STDIO Server:

java -jar target/mcp-server-java-1.0.0.jar

git hub integration

in command prompt in git directory: git status On branch main nothing to commit, working tree clean PS C:\Users\stethompson\Microsoft\MCP_Server_Java> git init Reinitialized existing Git repository in C:/Users/stethompson/Microsoft/MCP_Server_Java/.git/ PS C:\Users\stethompson\Microsoft\MCP_Server_Java> git add . PS C:\Users\stethompson\Microsoft\MCP_Server_Java> git remote add origin https://github.com/SteveThompson_msftcae/MCP_SERVER_JAVA.git git remove -v (check remote exists) PS C:\Users\stethompson\Microsoft\MCP_Server_Java> git branch -M main PS C:\Users\stethompson\Microsoft\MCP_Server_Java> git push -u origin main info: please complete authentication in your browser... fatal: The request is not supported Username for 'https://github.com': (authenticated with code) PS C:\Users\stethompson\Microsoft\MCP_Server_Java> git push -u origin main Enumerating objects: 48, done. Counting objects: 100% (48/48), done. Delta compression using up to 8 threads Compressing objects: 100% (31/31), done. Writing objects: 100% (48/48), 23.38 KiB | 1.80 MiB/s, done. Total 48 (delta 8), reused 0 (delta 0), pack-reused 0 (from 0) remote: Resolving deltas: 100% (8/8), done. To https://github.com/SteveThompson_msftcae/MCP_SERVER_JAVA.git * [new branch] main -> main branch 'main' set up to track 'origin/main'.

With Claude Desktop

Add the server to your Claude Desktop configuration:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "mcp-server-java": {
      "command": "java",
      "args": [
        "-jar",
        "C:\\absolute\\path\\to\\target\\mcp-server-java-1.0.0.jar"
      ]
    }
  }
}

Replace the path with the absolute path to your JAR file.

With VS Code

The server is already configured in .vscode/mcp.json. After building:

1. Open VS Code
2. Press Cmd+Shift+P (Mac) or Ctrl+Shift+P (Windows)
3. Select "MCP: Add server..."
4. The server will be available to connect

Development

Project Structure

mcp-server-java/
├── src/
│   └── main/
│       └── java/
│           └── com/
│               └── example/
│                   └── mcp/
│                       ├── Main.java              # Entry point
│                       ├── ToolsProvider.java     # Tool implementations
│                       ├── ResourcesProvider.java # Resource implementations
│                       └── PromptsProvider.java   # Prompt implementations
├── .vscode/
│   └── mcp.json                  # VS Code MCP configuration
├── pom.xml                       # Maven configuration
└── README.md                     # This file

Adding New Tools

To add a new tool:

1. Open src/main/java/com/example/mcp/ToolsProvider.java
2. Add the tool definition in registerTools()
3. Implement the tool logic in the switch statement

Example:

// In the list tools handler
Tool myTool = new Tool();
myTool.setName("my_tool");
myTool.setDescription("Description of what my tool does");
// ... set input schema
tools.add(myTool);

// In the call tool handler
case "my_tool":
    // Your implementation here
    break;

Adding New Resources

To add a new resource:

1. Open src/main/java/com/example/mcp/ResourcesProvider.java
2. Add the resource in registerResources()
3. Implement the read handler for your resource URI

Testing with MCP Inspector

You can test your server using the MCP Inspector:

npx @modelcontextprotocol/inspector java -jar target/mcp-server-java-1.0.0.jar

Debugging

The server uses SLF4J for logging. Logs are written to stderr and will appear in your terminal or the client's log viewer.

To enable verbose logging, you can adjust the logging level in your slf4j configuration.

Learn More

• Model Context Protocol Documentation
• MCP Java SDK
• MCP Specification

License

MIT License - See LICENSE file for details