MCP Java SDK Examples

A collection of MCP examples developed with Java SDKs.

Requirements

• Java 17 or later
• Maven 3.9.16 or the included Maven Wrapper

What is MCP?

The Model Context Protocol (MCP) lets servers expose data and functionality to LLM applications in a standardized way. MCP servers can expose resources, tools, prompts, and more.

Examples

• JDBC Server - Exposes JDBC database metadata through an MCP resource

JDBC Server

The JDBC example includes an annotated-sdk implementation backed by a JDBC connection.
The packaged server starts in STDIO mode by default.

Implemented resource:

• db://schema - Returns database product/version plus table and column metadata as JSON

JDBC configuration for the MCP server process:

• JDBC_URL is required
• JDBC_USERNAME is optional
• JDBC_PASSWORD is optional

Bundled sample database:

• mcp-server-jdbc/mcp-server-jdbc-common/src/test/resources/sqlite3.db

Build the MCP server jar first:

./mvnw -pl mcp-server-jdbc/mcp-server-jdbc-annotated-sdk -am package

On Windows PowerShell, use .\mvnw.cmd instead of ./mvnw.

The jar is created at:

• mcp-server-jdbc/mcp-server-jdbc-annotated-sdk/target/mcp-server-jdbc-annotated-sdk.jar

Use these paths in the examples below:

• <repo> - absolute path to this repository
• <jar> - <repo>/mcp-server-jdbc/mcp-server-jdbc-annotated-sdk/target/mcp-server-jdbc-annotated-sdk.jar
• <sqlite3.db> - <repo>/mcp-server-jdbc/mcp-server-jdbc-common/src/test/resources/sqlite3.db

For Windows paths in JSON/TOML, prefer forward slashes, for example C:/Users/me/code/mcp-java-sdk-examples/....

MCP Inspector

Start Inspector with the JDBC server as a STDIO server:

npx @modelcontextprotocol/inspector -e JDBC_URL=jdbc:sqlite:<sqlite3.db> -- java -jar <jar>

Open the Inspector URL printed in the terminal, then browse the db://schema resource.

Claude Desktop

Add the server to Claude Desktop MCP settings:

{
  "mcpServers": {
    "jdbc-mcp-server": {
      "command": "java",
      "args": ["-jar", "<jar>"],
      "env": {
        "JDBC_URL": "jdbc:sqlite:<sqlite3.db>"
      }
    }
  }
}

Restart Claude Desktop, then browse the db://schema resource from the MCP tools/resources panel.

Codex

Add the server with the Codex CLI:

codex mcp add jdbc-mcp-server --env JDBC_URL=jdbc:sqlite:<sqlite3.db> -- java -jar <jar>

Or add it to ~/.codex/config.toml or a trusted project .codex/config.toml:

[mcp_servers.jdbc-mcp-server]
command = "java"
args = ["-jar", "<jar>"]

[mcp_servers.jdbc-mcp-server.env]
JDBC_URL = "jdbc:sqlite:<sqlite3.db>"

Cursor

Add this server in Cursor MCP settings:

{
  "mcpServers": {
    "jdbc-mcp-server": {
      "command": "java",
      "args": ["-jar", "<jar>"],
      "env": {
        "JDBC_URL": "jdbc:sqlite:<sqlite3.db>"
      }
    }
  }
}

Cline

Open Cline MCP settings and add:

{
  "mcpServers": {
    "jdbc-mcp-server": {
      "command": "java",
      "args": ["-jar", "<jar>"],
      "env": {
        "JDBC_URL": "jdbc:sqlite:<sqlite3.db>"
      }
    }
  }
}

VS Code

Create or update .vscode/mcp.json:

{
  "servers": {
    "jdbc-mcp-server": {
      "type": "stdio",
      "command": "java",
      "args": ["-jar", "<jar>"],
      "env": {
        "JDBC_URL": "jdbc:sqlite:<sqlite3.db>"
      }
    }
  }
}

For databases that require credentials, add them to the MCP server environment:

"env": {
  "JDBC_URL": "jdbc:postgresql://localhost:5432/example",
  "JDBC_USERNAME": "user",
  "JDBC_PASSWORD": "password"
}