Java MCP Server Generator Generate a complete, production-ready MCP server in Java using the official Java SDK with Maven or Gradle. Project Generation When asked to create a Java MCP server, generate a complete project with this structure: my-mcp-server/ ├── pom.xml (or build.gradle.kts) ├── src/ │ ├── main/ │ │ ├── java/ │ │ │ └── com/example/mcp/ │ │ │ ├── McpServerApplication.java │ │ │ ├── config/ │ │ │ │ └── ServerConfiguration.java │ │ │ ├── tools/ │ │ │ │ ├── ToolDefinitions.java │ │ │ │ └── ToolHandlers.java │ │ │ ├── resources/ │ │ │ │ ├── ResourceDefinitions.java │ │ │ │ └── ResourceHandlers.java │ │ │ └── prompts/ │ │ │ ├── PromptDefinitions.java │ │ │ └── PromptHandlers.java │ │ └── resources/ │ │ └── application.properties (if using Spring) │ └── test/ │ └── java/ │ └── com/example/mcp/ │ └── McpServerTest.java └── README.md Maven pom.xml Template

< project xmlns = " http://maven.apache.org/POM/4.0.0 " xmlns: xsi = " http://www.w3.org/2001/XMLSchema-instance " xsi: schemaLocation = " http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd "

< modelVersion

4.0.0 </ modelVersion

< groupId

com.example </ groupId

< artifactId

my-mcp-server </ artifactId

< version

1.0.0 </ version

< packaging

jar </ packaging

< name

My MCP Server </ name

< description

Model Context Protocol server implementation </ description

< properties

< java.version

17 </ java.version

< maven.compiler.source

17 </ maven.compiler.source

< maven.compiler.target

17 </ maven.compiler.target

< project.build.sourceEncoding

UTF-8 </ project.build.sourceEncoding

< mcp.version

0.14.1 </ mcp.version

< slf4j.version

2.0.9 </ slf4j.version

< logback.version

1.4.11 </ logback.version

< junit.version

5.10.0 </ junit.version

</ properties

< dependencies

< dependency

< groupId

io.modelcontextprotocol.sdk </ groupId

< artifactId

mcp </ artifactId

< version

${mcp.version} </ version

</ dependency

< dependency

< groupId

org.slf4j </ groupId

< artifactId

slf4j-api </ artifactId

< version

${slf4j.version} </ version

</ dependency

< dependency

< groupId

ch.qos.logback </ groupId

< artifactId

logback-classic </ artifactId

< version

${logback.version} </ version

</ dependency

< dependency

< groupId

org.junit.jupiter </ groupId

< artifactId

junit-jupiter </ artifactId

< version

${junit.version} </ version

< scope

test </ scope

</ dependency

< dependency

< groupId

io.projectreactor </ groupId

< artifactId

reactor-test </ artifactId

< scope

test </ scope

</ dependency

</ dependencies

< build

< plugins

< plugin

< groupId

org.apache.maven.plugins </ groupId

< artifactId

maven-compiler-plugin </ artifactId

< version

3.11.0 </ version

</ plugin

< plugin

< groupId

org.apache.maven.plugins </ groupId

< artifactId

maven-surefire-plugin </ artifactId

< version

3.1.2 </ version

</ plugin

< plugin

< groupId

org.apache.maven.plugins </ groupId

< artifactId

maven-shade-plugin </ artifactId

< version

3.5.0 </ version

< executions

< execution

< phase

package </ phase

< goals

< goal

shade </ goal

</ goals

< configuration

< transformers

< transformer implementation = " org.apache.maven.plugins.shade.resource.ManifestResourceTransformer "

< mainClass

com.example.mcp.McpServerApplication </ mainClass

</ transformer

</ transformers

</ configuration

</ execution

</ executions

</ plugin

</ plugins

</ build

</ project

Gradle build.gradle.kts Template plugins { id ( "java" ) id ( "application" ) } group = "com.example" version = "1.0.0" java { sourceCompatibility = JavaVersion . VERSION_17 targetCompatibility = JavaVersion . VERSION_17 } repositories { mavenCentral ( ) } dependencies { // MCP Java SDK implementation ( "io.modelcontextprotocol.sdk:mcp:0.14.1" ) // Logging implementation ( "org.slf4j:slf4j-api:2.0.9" ) implementation ( "ch.qos.logback:logback-classic:1.4.11" ) // Testing testImplementation ( "org.junit.jupiter:junit-jupiter:5.10.0" ) testImplementation ( "io.projectreactor:reactor-test:3.5.0" ) } application { mainClass . set ( "com.example.mcp.McpServerApplication" ) } tasks . test { useJUnitPlatform ( ) } McpServerApplication.java Template package com . example . mcp ; import com . example . mcp . tools . ToolHandlers ; import com . example . mcp . resources . ResourceHandlers ; import com . example . mcp . prompts . PromptHandlers ; import io . mcp . server . McpServer ; import io . mcp . server . McpServerBuilder ; import io . mcp . server . transport . StdioServerTransport ; import org . slf4j . Logger ; import org . slf4j . LoggerFactory ; import reactor . core . Disposable ; public class McpServerApplication { private static final Logger log = LoggerFactory . getLogger ( McpServerApplication . class ) ; public static void main ( String [ ] args ) { log . info ( "Starting MCP Server..." ) ; try { McpServer server = createServer ( ) ; StdioServerTransport transport = new StdioServerTransport ( ) ; // Start server Disposable serverDisposable = server . start ( transport ) . subscribe ( ) ; // Graceful shutdown Runtime . getRuntime ( ) . addShutdownHook ( new Thread ( ( ) -> { log . info ( "Shutting down MCP server" ) ; serverDisposable . dispose ( ) ; server . stop ( ) . block ( ) ; } ) ) ; log . info ( "MCP Server started successfully" ) ; // Keep running Thread . currentThread ( ) . join ( ) ; } catch ( Exception e ) { log . error ( "Failed to start MCP server" , e ) ; System . exit ( 1 ) ; } } private static McpServer createServer ( ) { McpServer server = McpServerBuilder . builder ( ) . serverInfo ( "my-mcp-server" , "1.0.0" ) . capabilities ( capabilities -> capabilities . tools ( true ) . resources ( true ) . prompts ( true ) ) . build ( ) ; // Register handlers ToolHandlers . register ( server ) ; ResourceHandlers . register ( server ) ; PromptHandlers . register ( server ) ; return server ; } } ToolDefinitions.java Template package com . example . mcp . tools ; import io . mcp . json . JsonSchema ; import io . mcp . server . tool . Tool ; import java . util . List ; public class ToolDefinitions { public static List < Tool

getTools ( ) { return List . of ( createGreetTool ( ) , createCalculateTool ( ) ) ; } private static Tool createGreetTool ( ) { return Tool . builder ( ) . name ( "greet" ) . description ( "Generate a greeting message" ) . inputSchema ( JsonSchema . object ( ) . property ( "name" , JsonSchema . string ( ) . description ( "Name to greet" ) . required ( true ) ) ) . build ( ) ; } private static Tool createCalculateTool ( ) { return Tool . builder ( ) . name ( "calculate" ) . description ( "Perform mathematical calculations" ) . inputSchema ( JsonSchema . object ( ) . property ( "operation" , JsonSchema . string ( ) . description ( "Operation to perform" ) . enumValues ( List . of ( "add" , "subtract" , "multiply" , "divide" ) ) . required ( true ) ) . property ( "a" , JsonSchema . number ( ) . description ( "First operand" ) . required ( true ) ) . property ( "b" , JsonSchema . number ( ) . description ( "Second operand" ) . required ( true ) ) ) . build ( ) ; } } ToolHandlers.java Template package com . example . mcp . tools ; import com . fasterxml . jackson . databind . JsonNode ; import io . mcp . server . McpServer ; import io . mcp . server . tool . ToolResponse ; import org . slf4j . Logger ; import org . slf4j . LoggerFactory ; import reactor . core . publisher . Mono ; public class ToolHandlers { private static final Logger log = LoggerFactory . getLogger ( ToolHandlers . class ) ; public static void register ( McpServer server ) { // Register tool list handler server . addToolListHandler ( ( ) -> { log . debug ( "Listing available tools" ) ; return Mono . just ( ToolDefinitions . getTools ( ) ) ; } ) ; // Register greet handler server . addToolHandler ( "greet" , ToolHandlers :: handleGreet ) ; // Register calculate handler server . addToolHandler ( "calculate" , ToolHandlers :: handleCalculate ) ; } private static Mono < ToolResponse

handleGreet ( JsonNode arguments ) { log . info ( "Greet tool called" ) ; if ( ! arguments . has ( "name" ) ) { return Mono . just ( ToolResponse . error ( ) . message ( "Missing 'name' parameter" ) . build ( ) ) ; } String name = arguments . get ( "name" ) . asText ( ) ; String greeting = "Hello, " + name + "! Welcome to MCP." ; log . debug ( "Generated greeting for: {}" , name ) ; return Mono . just ( ToolResponse . success ( ) . addTextContent ( greeting ) . build ( ) ) ; } private static Mono < ToolResponse

handleCalculate ( JsonNode arguments ) { log . info ( "Calculate tool called" ) ; if ( ! arguments . has ( "operation" ) || ! arguments . has ( "a" ) || ! arguments . has ( "b" ) ) { return Mono . just ( ToolResponse . error ( ) . message ( "Missing required parameters" ) . build ( ) ) ; } String operation = arguments . get ( "operation" ) . asText ( ) ; double a = arguments . get ( "a" ) . asDouble ( ) ; double b = arguments . get ( "b" ) . asDouble ( ) ; double result ; switch ( operation ) { case "add" : result = a + b ; break ; case "subtract" : result = a - b ; break ; case "multiply" : result = a * b ; break ; case "divide" : if ( b == 0 ) { return Mono . just ( ToolResponse . error ( ) . message ( "Division by zero" ) . build ( ) ) ; } result = a / b ; break ; default : return Mono . just ( ToolResponse . error ( ) . message ( "Unknown operation: " + operation ) . build ( ) ) ; } log . debug ( "Calculation: {} {} {} = {}" , a , operation , b , result ) ; return Mono . just ( ToolResponse . success ( ) . addTextContent ( "Result: " + result ) . build ( ) ) ; } } ResourceDefinitions.java Template package com . example . mcp . resources ; import io . mcp . server . resource . Resource ; import java . util . List ; public class ResourceDefinitions { public static List < Resource

getResources ( ) { return List . of ( Resource . builder ( ) . name ( "Example Data" ) . uri ( "resource://data/example" ) . description ( "Example resource data" ) . mimeType ( "application/json" ) . build ( ) , Resource . builder ( ) . name ( "Configuration" ) . uri ( "resource://config" ) . description ( "Server configuration" ) . mimeType ( "application/json" ) . build ( ) ) ; } } ResourceHandlers.java Template package com . example . mcp . resources ; import io . mcp . server . McpServer ; import io . mcp . server . resource . ResourceContent ; import org . slf4j . Logger ; import org . slf4j . LoggerFactory ; import reactor . core . publisher . Mono ; import java . time . Instant ; import java . util . Map ; import java . util . concurrent . ConcurrentHashMap ; public class ResourceHandlers { private static final Logger log = LoggerFactory . getLogger ( ResourceHandlers . class ) ; private static final Map < String , Boolean

subscriptions

new ConcurrentHashMap <

( ) ; public static void register ( McpServer server ) { // Register resource list handler server . addResourceListHandler ( ( ) -> { log . debug ( "Listing available resources" ) ; return Mono . just ( ResourceDefinitions . getResources ( ) ) ; } ) ; // Register resource read handler server . addResourceReadHandler ( ResourceHandlers :: handleRead ) ; // Register resource subscribe handler server . addResourceSubscribeHandler ( ResourceHandlers :: handleSubscribe ) ; // Register resource unsubscribe handler server . addResourceUnsubscribeHandler ( ResourceHandlers :: handleUnsubscribe ) ; } private static Mono < ResourceContent

handleRead ( String uri ) { log . info ( "Reading resource: {}" , uri ) ; switch ( uri ) { case "resource://data/example" : String jsonData = String . format ( "{\"message\":\"Example resource data\",\"timestamp\":\"%s\"}" , Instant . now ( ) ) ; return Mono . just ( ResourceContent . text ( jsonData , uri , "application/json" ) ) ; case "resource://config" : String config = "{\"serverName\":\"my-mcp-server\",\"version\":\"1.0.0\"}" ; return Mono . just ( ResourceContent . text ( config , uri , "application/json" ) ) ; default : log . warn ( "Unknown resource requested: {}" , uri ) ; return Mono . error ( new IllegalArgumentException ( "Unknown resource URI: " + uri ) ) ; } } private static Mono < Void

handleSubscribe ( String uri ) { log . info ( "Client subscribed to resource: {}" , uri ) ; subscriptions . put ( uri , true ) ; return Mono . empty ( ) ; } private static Mono < Void

handleUnsubscribe ( String uri ) { log . info ( "Client unsubscribed from resource: {}" , uri ) ; subscriptions . remove ( uri ) ; return Mono . empty ( ) ; } } PromptDefinitions.java Template package com . example . mcp . prompts ; import io . mcp . server . prompt . Prompt ; import io . mcp . server . prompt . PromptArgument ; import java . util . List ; public class PromptDefinitions { public static List < Prompt

getPrompts ( ) { return List . of ( Prompt . builder ( ) . name ( "code-review" ) . description ( "Generate a code review prompt" ) . argument ( PromptArgument . builder ( ) . name ( "language" ) . description ( "Programming language" ) . required ( true ) . build ( ) ) . argument ( PromptArgument . builder ( ) . name ( "focus" ) . description ( "Review focus area" ) . required ( false ) . build ( ) ) . build ( ) ) ; } } PromptHandlers.java Template package com . example . mcp . prompts ; import io . mcp . server . McpServer ; import io . mcp . server . prompt . PromptMessage ; import io . mcp . server . prompt . PromptResult ; import org . slf4j . Logger ; import org . slf4j . LoggerFactory ; import reactor . core . publisher . Mono ; import java . util . List ; import java . util . Map ; public class PromptHandlers { private static final Logger log = LoggerFactory . getLogger ( PromptHandlers . class ) ; public static void register ( McpServer server ) { // Register prompt list handler server . addPromptListHandler ( ( ) -> { log . debug ( "Listing available prompts" ) ; return Mono . just ( PromptDefinitions . getPrompts ( ) ) ; } ) ; // Register prompt get handler server . addPromptGetHandler ( PromptHandlers :: handleCodeReview ) ; } private static Mono < PromptResult

handleCodeReview ( String name , Map < String , String

arguments ) { log . info ( "Getting prompt: {}" , name ) ; if ( ! name . equals ( "code-review" ) ) { return Mono . error ( new IllegalArgumentException ( "Unknown prompt: " + name ) ) ; } String language = arguments . getOrDefault ( "language" , "Java" ) ; String focus = arguments . getOrDefault ( "focus" , "general quality" ) ; String description = "Code review for " + language + " with focus on " + focus ; List < PromptMessage

messages

List . of ( PromptMessage . user ( "Please review this " + language + " code with focus on " + focus + "." ) , PromptMessage . assistant ( "I'll review the code focusing on " + focus + ". Please share the code." ) , PromptMessage . user ( "Here's the code to review: [paste code here]" ) ) ; log . debug ( "Generated code review prompt for {} ({})" , language , focus ) ; return Mono . just ( PromptResult . builder ( ) . description ( description ) . messages ( messages ) . build ( ) ) ; } } McpServerTest.java Template package com . example . mcp ; import com . fasterxml . jackson . databind . ObjectMapper ; import com . fasterxml . jackson . databind . node . ObjectNode ; import io . mcp . server . McpServer ; import io . mcp . server . McpSyncServer ; import io . mcp . server . tool . ToolResponse ; import org . junit . jupiter . api . BeforeEach ; import org . junit . jupiter . api . Test ; import static org . junit . jupiter . api . Assertions . * ; class McpServerTest { private McpSyncServer syncServer ; private ObjectMapper objectMapper ; @BeforeEach void setUp ( ) { McpServer server = createTestServer ( ) ; syncServer = server . toSyncServer ( ) ; objectMapper = new ObjectMapper ( ) ; } private McpServer createTestServer ( ) { // Same setup as main application McpServer server = McpServerBuilder . builder ( ) . serverInfo ( "test-server" , "1.0.0" ) . capabilities ( cap -> cap . tools ( true ) ) . build ( ) ; // Register handlers ToolHandlers . register ( server ) ; return server ; } @Test void testGreetTool ( ) { ObjectNode args = objectMapper . createObjectNode ( ) ; args . put ( "name" , "Java" ) ; ToolResponse response = syncServer . callTool ( "greet" , args ) ; assertFalse ( response . isError ( ) ) ; assertEquals ( 1 , response . getContent ( ) . size ( ) ) ; assertTrue ( response . getContent ( ) . get ( 0 ) . getText ( ) . contains ( "Java" ) ) ; } @Test void testCalculateTool ( ) { ObjectNode args = objectMapper . createObjectNode ( ) ; args . put ( "operation" , "add" ) ; args . put ( "a" , 5 ) ; args . put ( "b" , 3 ) ; ToolResponse response = syncServer . callTool ( "calculate" , args ) ; assertFalse ( response . isError ( ) ) ; assertTrue ( response . getContent ( ) . get ( 0 ) . getText ( ) . contains ( "8" ) ) ; } @Test void testDivideByZero ( ) { ObjectNode args = objectMapper . createObjectNode ( ) ; args . put ( "operation" , "divide" ) ; args . put ( "a" , 10 ) ; args . put ( "b" , 0 ) ; ToolResponse response = syncServer . callTool ( "calculate" , args ) ; assertTrue ( response . isError ( ) ) ; } } README.md Template

My MCP Server A Model Context Protocol server built with Java and the official MCP Java SDK.

Features

✅ Tools: greet, calculate

✅ Resources: example data, configuration

✅ Prompts: code-review

✅ Reactive Streams with Project Reactor

✅ Structured logging with SLF4J

✅ Full test coverage

Requirements

Java 17 or later

Maven 3.6+ or Gradle 7+

Build

Maven ```bash mvn clean package Gradle ./gradlew build Run Maven java -jar target/my-mcp-server-1.0.0.jar Gradle ./gradlew run Testing Maven mvn test Gradle ./gradlew test Integration with Claude Desktop Add to claude_desktop_config.json : { "mcpServers" : { "my-mcp-server" : { "command" : "java" , "args" : [ "-jar" , "/path/to/my-mcp-server-1.0.0.jar" ] } } } License MIT

Generation Instructions

1. Ask for project name and package
2. Choose build tool (Maven or Gradle)
3. Generate all files with proper package structure
4. Use Reactive Streams for async handlers
5. Include comprehensive logging with SLF4J
6. Add tests for all handlers
7. Follow Java conventions (camelCase, PascalCase)
8. Include error handling with proper responses
9. Document public APIs with Javadoc
10. Provide both sync and async examples