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Move mcp-json into mcp-core, add OSGi support

Browse source 
Co-authored-by: Luca Chang <131398524+LucaButBoring@users.noreply.github.com>
Signed-off-by: Daniel Garnier-Moiroux <git@garnier.wf>
This commit is contained in:
Scott Lewis 2026-01-28 15:43:23 -08:00 • committed by Daniel Garnier-Moiroux
commit c3b9ab09ea
47 changed files with 368 additions and 353 deletions
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7
mcp-bom/pom.xml
View file

@ -40,13 +40,6 @@
<version>${project.version}</version>
</dependency>
<!-- MCP JSON -->
<dependency>
<groupId>io.modelcontextprotocol.sdk</groupId>
<artifactId>mcp-json</artifactId>
<version>${project.version}</version>
</dependency>
<!-- MCP JSON Jackson -->
<dependency>
<groupId>io.modelcontextprotocol.sdk</groupId>

20
mcp-core/pom.xml
View file

@ -41,6 +41,7 @@
Automatic-Module-Name: ${project.groupId}.${project.artifactId}
Import-Package: jakarta.*;resolution:=optional, \
*;
Service-Component: OSGI-INF/io.modelcontextprotocol.json.McpJsonDefaults.xml
Export-Package: io.modelcontextprotocol.*;version="${version}";-noimport:=true
-noimportjava: true;
-nouses: true;
@ -65,11 +66,6 @@
</build>
<dependencies>
<dependency>
<groupId>io.modelcontextprotocol.sdk</groupId>
<artifactId>mcp-json</artifactId>
<version>0.18.0-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
@ -97,14 +93,6 @@
<scope>provided</scope>
</dependency>
<!-- Test dependencies -->
<dependency>
<groupId>io.modelcontextprotocol.sdk</groupId>
<artifactId>mcp-json-jackson3</artifactId>
<version>0.18.0-SNAPSHOT</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
@ -112,6 +100,12 @@
<scope>test</scope>
</dependency>
<dependency>
<groupId>tools.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>${jackson3.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>io.projectreactor.netty</groupId>

12
mcp-core/src/main/java/io/modelcontextprotocol/client/McpClient.java
View file

@ -5,6 +5,7 @@
package io.modelcontextprotocol.client;
import io.modelcontextprotocol.common.McpTransportContext;
import io.modelcontextprotocol.json.McpJsonDefaults;
import io.modelcontextprotocol.json.schema.JsonSchemaValidator;
import io.modelcontextprotocol.spec.McpClientTransport;
import io.modelcontextprotocol.spec.McpSchema;
@ -491,9 +492,12 @@ public interface McpClient {
McpClientFeatures.Async asyncFeatures = McpClientFeatures.Async.fromSync(syncFeatures);
return new McpSyncClient(new McpAsyncClient(transport, this.requestTimeout, this.initializationTimeout,
jsonSchemaValidator != null ? jsonSchemaValidator : JsonSchemaValidator.getDefault(),
asyncFeatures), this.contextProvider);
return new McpSyncClient(
new McpAsyncClient(transport, this.requestTimeout, this.initializationTimeout,
jsonSchemaValidator != null ? jsonSchemaValidator
: McpJsonDefaults.getDefaultJsonSchemaValidator(),
asyncFeatures),
this.contextProvider);
}
}
@ -826,7 +830,7 @@ public interface McpClient {
*/
public McpAsyncClient build() {
var jsonSchemaValidator = (this.jsonSchemaValidator != null) ? this.jsonSchemaValidator
: JsonSchemaValidator.getDefault();
: McpJsonDefaults.getDefaultJsonSchemaValidator();
return new McpAsyncClient(this.transport, this.requestTimeout, this.initializationTimeout,
jsonSchemaValidator,
new McpClientFeatures.Async(this.clientInfo, this.capabilities, this.roots,

3
mcp-core/src/main/java/io/modelcontextprotocol/client/transport/HttpClientSseClientTransport.java
View file

@ -22,6 +22,7 @@ import io.modelcontextprotocol.client.transport.ResponseSubscribers.ResponseEven
import io.modelcontextprotocol.client.transport.customizer.McpAsyncHttpClientRequestCustomizer;
import io.modelcontextprotocol.client.transport.customizer.McpSyncHttpClientRequestCustomizer;
import io.modelcontextprotocol.common.McpTransportContext;
import io.modelcontextprotocol.json.McpJsonDefaults;
import io.modelcontextprotocol.json.McpJsonMapper;
import io.modelcontextprotocol.json.TypeRef;
import io.modelcontextprotocol.spec.HttpHeaders;
@ -327,7 +328,7 @@ public class HttpClientSseClientTransport implements McpClientTransport {
public HttpClientSseClientTransport build() {
HttpClient httpClient = this.clientBuilder.connectTimeout(this.connectTimeout).build();
return new HttpClientSseClientTransport(httpClient, requestBuilder, baseUri, sseEndpoint,
jsonMapper == null ? McpJsonMapper.getDefault() : jsonMapper, httpRequestCustomizer);
jsonMapper == null ? McpJsonDefaults.getDefaultMcpJsonMapper() : jsonMapper, httpRequestCustomizer);
}
}

8
mcp-core/src/main/java/io/modelcontextprotocol/client/transport/HttpClientStreamableHttpTransport.java
View file

@ -25,6 +25,7 @@ import io.modelcontextprotocol.client.transport.ResponseSubscribers.ResponseEven
import io.modelcontextprotocol.client.transport.customizer.McpAsyncHttpClientRequestCustomizer;
import io.modelcontextprotocol.client.transport.customizer.McpSyncHttpClientRequestCustomizer;
import io.modelcontextprotocol.common.McpTransportContext;
import io.modelcontextprotocol.json.McpJsonDefaults;
import io.modelcontextprotocol.json.McpJsonMapper;
import io.modelcontextprotocol.json.TypeRef;
import io.modelcontextprotocol.spec.ClosedMcpTransportSession;
@ -842,9 +843,10 @@ public class HttpClientStreamableHttpTransport implements McpClientTransport {
*/
public HttpClientStreamableHttpTransport build() {
HttpClient httpClient = this.clientBuilder.connectTimeout(this.connectTimeout).build();
return new HttpClientStreamableHttpTransport(jsonMapper == null ? McpJsonMapper.getDefault() : jsonMapper,
httpClient, requestBuilder, baseUri, endpoint, resumableStreams, openConnectionOnStartup,
httpRequestCustomizer, supportedProtocolVersions);
return new HttpClientStreamableHttpTransport(
jsonMapper == null ? McpJsonDefaults.getDefaultMcpJsonMapper() : jsonMapper, httpClient,
requestBuilder, baseUri, endpoint, resumableStreams, openConnectionOnStartup, httpRequestCustomizer,
supportedProtocolVersions);
}
}

76
mcp-core/src/main/java/io/modelcontextprotocol/json/McpJsonDefaults.java Normal file
View file

@ -0,0 +1,76 @@
/**
* Copyright 2026 - 2026 the original author or authors.
*/
package io.modelcontextprotocol.json;
import io.modelcontextprotocol.json.schema.JsonSchemaValidator;
import io.modelcontextprotocol.json.schema.JsonSchemaValidatorSupplier;
import io.modelcontextprotocol.util.McpServiceLoader;
/**
* This class is to be used to provide access to the default McpJsonMapper and to the
* default JsonSchemaValidator instances via the static methods: getDefaultMcpJsonMapper
* and getDefaultJsonSchemaValidator.
* <p>
* The initialization of (singleton) instances of this class is different in non-OSGi
* environments and OSGi environments. Specifically, in non-OSGi environments The
* McpJsonDefaults class will be loaded by whatever classloader is used to call one of the
* existing static get methods for the first time. For servers, this will usually be in
* response to the creation of the first McpServer instance. At that first time, the
* mcpMapperServiceLoader and mcpValidatorServiceLoader will be null, and the
* McpJsonDefaults constructor will be called, creating/initializing the
* mcpMapperServiceLoader and the mcpValidatorServiceLoader...which will then be used to
* call the ServiceLoader.load method.
* <p>
* In OSGi environments, upon bundle activation SCR will create a new (singleton) instance
* of McpJsonDefaults (via the constructor), and then inject suppliers via the
* setMcpJsonMapperSupplier and setJsonSchemaValidatorSupplier methods with the
* SCR-discovered instances of those services. This does depend upon the jars/bundles
* providing those suppliers to be started/activated. This SCR behavior is dictated by xml
* files in OSGi-INF directory of mcp-core (this project/jar/bundle), and the jsonmapper
* and jsonschemvalidator provider jars/bundles (e.g. mcp-json-jackson2, 3, or others).
*/
public class McpJsonDefaults {
protected static McpServiceLoader<McpJsonMapperSupplier, McpJsonMapper> mcpMapperServiceLoader;
protected static McpServiceLoader<JsonSchemaValidatorSupplier, JsonSchemaValidator> mcpValidatorServiceLoader;
public McpJsonDefaults() {
mcpMapperServiceLoader = new McpServiceLoader<McpJsonMapperSupplier, McpJsonMapper>(
McpJsonMapperSupplier.class);
mcpValidatorServiceLoader = new McpServiceLoader<JsonSchemaValidatorSupplier, JsonSchemaValidator>(
JsonSchemaValidatorSupplier.class);
}
void setMcpJsonMapperSupplier(McpJsonMapperSupplier supplier) {
mcpMapperServiceLoader.setSupplier(supplier);
}
void unsetMcpJsonMapperSupplier(McpJsonMapperSupplier supplier) {
mcpMapperServiceLoader.unsetSupplier(supplier);
}
public synchronized static McpJsonMapper getDefaultMcpJsonMapper() {
if (mcpMapperServiceLoader == null) {
new McpJsonDefaults();
}
return mcpMapperServiceLoader.getDefault();
}
void setJsonSchemaValidatorSupplier(JsonSchemaValidatorSupplier supplier) {
mcpValidatorServiceLoader.setSupplier(supplier);
}
void unsetJsonSchemaValidatorSupplier(JsonSchemaValidatorSupplier supplier) {
mcpValidatorServiceLoader.unsetSupplier(supplier);
}
public synchronized static JsonSchemaValidator getDefaultJsonSchemaValidator() {
if (mcpValidatorServiceLoader == null) {
new McpJsonDefaults();
}
return mcpValidatorServiceLoader.getDefault();
}
}

90
mcp-core/src/main/java/io/modelcontextprotocol/json/McpJsonMapper.java Normal file
View file

@ -0,0 +1,90 @@
/*
* Copyright 2025 - 2025 the original author or authors.
*/
package io.modelcontextprotocol.json;
import java.io.IOException;
/**
* Abstraction for JSON serialization/deserialization to decouple the SDK from any
* specific JSON library. A default implementation backed by Jackson is provided in
* io.modelcontextprotocol.spec.json.jackson.JacksonJsonMapper.
*/
public interface McpJsonMapper {
/**
* Deserialize JSON string into a target type.
* @param content JSON as String
* @param type target class
* @return deserialized instance
* @param <T> generic type
* @throws IOException on parse errors
*/
<T> T readValue(String content, Class<T> type) throws IOException;
/**
* Deserialize JSON bytes into a target type.
* @param content JSON as bytes
* @param type target class
* @return deserialized instance
* @param <T> generic type
* @throws IOException on parse errors
*/
<T> T readValue(byte[] content, Class<T> type) throws IOException;
/**
* Deserialize JSON string into a parameterized target type.
* @param content JSON as String
* @param type parameterized type reference
* @return deserialized instance
* @param <T> generic type
* @throws IOException on parse errors
*/
<T> T readValue(String content, TypeRef<T> type) throws IOException;
/**
* Deserialize JSON bytes into a parameterized target type.
* @param content JSON as bytes
* @param type parameterized type reference
* @return deserialized instance
* @param <T> generic type
* @throws IOException on parse errors
*/
<T> T readValue(byte[] content, TypeRef<T> type) throws IOException;
/**
* Convert a value to a given type, useful for mapping nested JSON structures.
* @param fromValue source value
* @param type target class
* @return converted value
* @param <T> generic type
*/
<T> T convertValue(Object fromValue, Class<T> type);
/**
* Convert a value to a given parameterized type.
* @param fromValue source value
* @param type target type reference
* @return converted value
* @param <T> generic type
*/
<T> T convertValue(Object fromValue, TypeRef<T> type);
/**
* Serialize an object to JSON string.
* @param value object to serialize
* @return JSON as String
* @throws IOException on serialization errors
*/
String writeValueAsString(Object value) throws IOException;
/**
* Serialize an object to JSON bytes.
* @param value object to serialize
* @return JSON as bytes
* @throws IOException on serialization errors
*/
byte[] writeValueAsBytes(Object value) throws IOException;
}

14
mcp-core/src/main/java/io/modelcontextprotocol/json/McpJsonMapperSupplier.java Normal file
View file

@ -0,0 +1,14 @@
/*
* Copyright 2025 - 2025 the original author or authors.
*/
package io.modelcontextprotocol.json;
import java.util.function.Supplier;
/**
* Strategy interface for resolving a {@link McpJsonMapper}.
*/
public interface McpJsonMapperSupplier extends Supplier<McpJsonMapper> {
}

44
mcp-core/src/main/java/io/modelcontextprotocol/json/TypeRef.java Normal file
View file

@ -0,0 +1,44 @@
/*
* Copyright 2025 - 2025 the original author or authors.
*/
package io.modelcontextprotocol.json;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
/**
* Captures generic type information at runtime for parameterized JSON (de)serialization.
* Usage: TypeRef<List<Foo>> ref = new TypeRef<>(){};
*/
public abstract class TypeRef<T> {
private final Type type;
/**
* Constructs a new TypeRef instance, capturing the generic type information of the
* subclass. This constructor should be called from an anonymous subclass to capture
* the actual type arguments. For example: <pre>
* TypeRef&lt;List&lt;Foo&gt;&gt; ref = new TypeRef&lt;&gt;(){};
* </pre>
* @throws IllegalStateException if TypeRef is not subclassed with actual type
* information
*/
protected TypeRef() {
Type superClass = getClass().getGenericSuperclass();
if (superClass instanceof Class) {
throw new IllegalStateException("TypeRef constructed without actual type information");
}
this.type = ((ParameterizedType) superClass).getActualTypeArguments()[0];
}
/**
* Returns the captured type information.
* @return the Type representing the actual type argument captured by this TypeRef
* instance
*/
public Type getType() {
return type;
}
}

44
mcp-core/src/main/java/io/modelcontextprotocol/json/schema/JsonSchemaValidator.java Normal file
View file

@ -0,0 +1,44 @@
/*
* Copyright 2024-2024 the original author or authors.
*/
package io.modelcontextprotocol.json.schema;
import java.util.Map;
/**
* Interface for validating structured content against a JSON schema. This interface
* defines a method to validate structured content based on the provided output schema.
*
* @author Christian Tzolov
*/
public interface JsonSchemaValidator {
/**
* Represents the result of a validation operation.
*
* @param valid Indicates whether the validation was successful.
* @param errorMessage An error message if the validation failed, otherwise null.
* @param jsonStructuredOutput The text structured content in JSON format if the
* validation was successful, otherwise null.
*/
record ValidationResponse(boolean valid, String errorMessage, String jsonStructuredOutput) {
public static ValidationResponse asValid(String jsonStructuredOutput) {
return new ValidationResponse(true, null, jsonStructuredOutput);
}
public static ValidationResponse asInvalid(String message) {
return new ValidationResponse(false, message, null);
}
}
/**
* Validates the structured content against the provided JSON schema.
* @param schema The JSON schema to validate against.
* @param structuredContent The structured content to validate.
* @return A ValidationResponse indicating whether the validation was successful or
* not.
*/
ValidationResponse validate(Map<String, Object> schema, Object structuredContent);
}

19
mcp-core/src/main/java/io/modelcontextprotocol/json/schema/JsonSchemaValidatorSupplier.java Normal file
View file

@ -0,0 +1,19 @@
/*
* Copyright 2025 - 2025 the original author or authors.
*/
package io.modelcontextprotocol.json.schema;
import java.util.function.Supplier;
/**
* A supplier interface that provides a {@link JsonSchemaValidator} instance.
* Implementations of this interface are expected to return a new or cached instance of
* {@link JsonSchemaValidator} when {@link #get()} is invoked.
*
* @see JsonSchemaValidator
* @see Supplier
*/
public interface JsonSchemaValidatorSupplier extends Supplier<JsonSchemaValidator> {
}

54
mcp-core/src/main/java/io/modelcontextprotocol/server/McpServer.java
View file

@ -4,7 +4,17 @@
package io.modelcontextprotocol.server;
import java.time.Duration;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.function.BiConsumer;
import java.util.function.BiFunction;
import io.modelcontextprotocol.common.McpTransportContext;
import io.modelcontextprotocol.json.McpJsonDefaults;
import io.modelcontextprotocol.json.McpJsonMapper;
import io.modelcontextprotocol.json.schema.JsonSchemaValidator;
import io.modelcontextprotocol.spec.McpSchema;
@ -18,11 +28,6 @@ import io.modelcontextprotocol.util.McpUriTemplateManagerFactory;
import io.modelcontextprotocol.util.ToolNameValidator;
import reactor.core.publisher.Mono;
import java.time.Duration;
import java.util.*;
import java.util.function.BiConsumer;
import java.util.function.BiFunction;
/**
* Factory class for creating Model Context Protocol (MCP) servers. MCP servers expose
* tools, resources, and prompts to AI models through a standardized interface.
@ -235,10 +240,11 @@ public interface McpServer {
this.instructions);
var jsonSchemaValidator = (this.jsonSchemaValidator != null) ? this.jsonSchemaValidator
: JsonSchemaValidator.getDefault();
: McpJsonDefaults.getDefaultJsonSchemaValidator();
return new McpAsyncServer(transportProvider, jsonMapper == null ? McpJsonMapper.getDefault() : jsonMapper,
features, requestTimeout, uriTemplateManagerFactory, jsonSchemaValidator);
return new McpAsyncServer(transportProvider,
jsonMapper == null ? McpJsonDefaults.getDefaultMcpJsonMapper() : jsonMapper, features,
requestTimeout, uriTemplateManagerFactory, jsonSchemaValidator);
}
}
@ -262,9 +268,10 @@ public interface McpServer {
this.resources, this.resourceTemplates, this.prompts, this.completions, this.rootsChangeHandlers,
this.instructions);
var jsonSchemaValidator = this.jsonSchemaValidator != null ? this.jsonSchemaValidator
: JsonSchemaValidator.getDefault();
return new McpAsyncServer(transportProvider, jsonMapper == null ? McpJsonMapper.getDefault() : jsonMapper,
features, requestTimeout, uriTemplateManagerFactory, jsonSchemaValidator);
: McpJsonDefaults.getDefaultJsonSchemaValidator();
return new McpAsyncServer(transportProvider,
jsonMapper == null ? McpJsonDefaults.getDefaultMcpJsonMapper() : jsonMapper, features,
requestTimeout, uriTemplateManagerFactory, jsonSchemaValidator);
}
}
@ -851,9 +858,9 @@ public interface McpServer {
this.immediateExecution);
var asyncServer = new McpAsyncServer(transportProvider,
jsonMapper == null ? McpJsonMapper.getDefault() : jsonMapper, asyncFeatures, requestTimeout,
uriTemplateManagerFactory,
jsonSchemaValidator != null ? jsonSchemaValidator : JsonSchemaValidator.getDefault());
jsonMapper == null ? McpJsonDefaults.getDefaultMcpJsonMapper() : jsonMapper, asyncFeatures,
requestTimeout, uriTemplateManagerFactory, jsonSchemaValidator != null ? jsonSchemaValidator
: McpJsonDefaults.getDefaultJsonSchemaValidator());
return new McpSyncServer(asyncServer, this.immediateExecution);
}
@ -881,10 +888,10 @@ public interface McpServer {
McpServerFeatures.Async asyncFeatures = McpServerFeatures.Async.fromSync(syncFeatures,
this.immediateExecution);
var jsonSchemaValidator = this.jsonSchemaValidator != null ? this.jsonSchemaValidator
: JsonSchemaValidator.getDefault();
: McpJsonDefaults.getDefaultJsonSchemaValidator();
var asyncServer = new McpAsyncServer(transportProvider,
jsonMapper == null ? McpJsonMapper.getDefault() : jsonMapper, asyncFeatures, this.requestTimeout,
this.uriTemplateManagerFactory, jsonSchemaValidator);
jsonMapper == null ? McpJsonDefaults.getDefaultMcpJsonMapper() : jsonMapper, asyncFeatures,
this.requestTimeout, this.uriTemplateManagerFactory, jsonSchemaValidator);
return new McpSyncServer(asyncServer, this.immediateExecution);
}
@ -1931,9 +1938,10 @@ public interface McpServer {
public McpStatelessAsyncServer build() {
var features = new McpStatelessServerFeatures.Async(this.serverInfo, this.serverCapabilities, this.tools,
this.resources, this.resourceTemplates, this.prompts, this.completions, this.instructions);
return new McpStatelessAsyncServer(transport, jsonMapper == null ? McpJsonMapper.getDefault() : jsonMapper,
features, requestTimeout, uriTemplateManagerFactory,
jsonSchemaValidator != null ? jsonSchemaValidator : JsonSchemaValidator.getDefault());
return new McpStatelessAsyncServer(transport,
jsonMapper == null ? McpJsonDefaults.getDefaultMcpJsonMapper() : jsonMapper, features,
requestTimeout, uriTemplateManagerFactory, jsonSchemaValidator != null ? jsonSchemaValidator
: McpJsonDefaults.getDefaultJsonSchemaValidator());
}
}
@ -2432,9 +2440,9 @@ public interface McpServer {
this.resources, this.resourceTemplates, this.prompts, this.completions, this.instructions);
var asyncFeatures = McpStatelessServerFeatures.Async.fromSync(syncFeatures, this.immediateExecution);
var asyncServer = new McpStatelessAsyncServer(transport,
jsonMapper == null ? McpJsonMapper.getDefault() : jsonMapper, asyncFeatures, requestTimeout,
uriTemplateManagerFactory,
this.jsonSchemaValidator != null ? this.jsonSchemaValidator : JsonSchemaValidator.getDefault());
jsonMapper == null ? McpJsonDefaults.getDefaultMcpJsonMapper() : jsonMapper, asyncFeatures,
requestTimeout, uriTemplateManagerFactory, this.jsonSchemaValidator != null
? this.jsonSchemaValidator : McpJsonDefaults.getDefaultJsonSchemaValidator());
return new McpStatelessSyncServer(asyncServer, this.immediateExecution);
}

5
mcp-core/src/main/java/io/modelcontextprotocol/server/transport/HttpServletSseServerTransportProvider.java
View file

@ -18,6 +18,7 @@ import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicBoolean;
import io.modelcontextprotocol.common.McpTransportContext;
import io.modelcontextprotocol.json.McpJsonDefaults;
import io.modelcontextprotocol.json.McpJsonMapper;
import io.modelcontextprotocol.json.TypeRef;
import io.modelcontextprotocol.server.McpTransportContextExtractor;
@ -689,8 +690,8 @@ public class HttpServletSseServerTransportProvider extends HttpServlet implement
throw new IllegalStateException("MessageEndpoint must be set");
}
return new HttpServletSseServerTransportProvider(
jsonMapper == null ? McpJsonMapper.getDefault() : jsonMapper, baseUrl, messageEndpoint, sseEndpoint,
keepAliveInterval, contextExtractor, securityValidator);
jsonMapper == null ? McpJsonDefaults.getDefaultMcpJsonMapper() : jsonMapper, baseUrl,
messageEndpoint, sseEndpoint, keepAliveInterval, contextExtractor, securityValidator);
}
}

6
mcp-core/src/main/java/io/modelcontextprotocol/server/transport/HttpServletStatelessServerTransport.java
View file

@ -16,6 +16,7 @@ import java.util.Map;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import io.modelcontextprotocol.json.McpJsonDefaults;
import io.modelcontextprotocol.json.McpJsonMapper;
import io.modelcontextprotocol.common.McpTransportContext;
@ -347,8 +348,9 @@ public class HttpServletStatelessServerTransport extends HttpServlet implements
*/
public HttpServletStatelessServerTransport build() {
Assert.notNull(mcpEndpoint, "Message endpoint must be set");
return new HttpServletStatelessServerTransport(jsonMapper == null ? McpJsonMapper.getDefault() : jsonMapper,
mcpEndpoint, contextExtractor, securityValidator);
return new HttpServletStatelessServerTransport(
jsonMapper == null ? McpJsonDefaults.getDefaultMcpJsonMapper() : jsonMapper, mcpEndpoint,
contextExtractor, securityValidator);
}
}

5
mcp-core/src/main/java/io/modelcontextprotocol/server/transport/HttpServletStreamableServerTransportProvider.java
View file

@ -32,6 +32,7 @@ import io.modelcontextprotocol.spec.McpStreamableServerTransport;
import io.modelcontextprotocol.spec.McpStreamableServerTransportProvider;
import io.modelcontextprotocol.spec.ProtocolVersions;
import io.modelcontextprotocol.util.Assert;
import io.modelcontextprotocol.json.McpJsonDefaults;
import io.modelcontextprotocol.json.McpJsonMapper;
import io.modelcontextprotocol.util.KeepAliveScheduler;
import jakarta.servlet.AsyncContext;
@ -912,8 +913,8 @@ public class HttpServletStreamableServerTransportProvider extends HttpServlet
public HttpServletStreamableServerTransportProvider build() {
Assert.notNull(this.mcpEndpoint, "MCP endpoint must be set");
return new HttpServletStreamableServerTransportProvider(
jsonMapper == null ? McpJsonMapper.getDefault() : jsonMapper, mcpEndpoint, disallowDelete,
contextExtractor, keepAliveInterval, securityValidator);
jsonMapper == null ? McpJsonDefaults.getDefaultMcpJsonMapper() : jsonMapper, mcpEndpoint,
disallowDelete, contextExtractor, keepAliveInterval, securityValidator);
}
}

68
mcp-core/src/main/java/io/modelcontextprotocol/util/McpServiceLoader.java Normal file
View file

@ -0,0 +1,68 @@
/**
* Copyright 2026 - 2026 the original author or authors.
*/
package io.modelcontextprotocol.util;
import java.util.Optional;
import java.util.ServiceConfigurationError;
import java.util.ServiceLoader;
import java.util.function.Supplier;
/**
* Instance of this class are intended to be used differently in OSGi and non-OSGi
* environments. In all non-OSGi environments the supplier member will be
* <code>null</code> and the serviceLoad method will be called to use the
* ServiceLoader.load to find the first instance of the supplier (assuming one is present
* in the runtime), cache it, and call the supplier's get method.
* <p>
* In OSGi environments, the Service component runtime (scr) will call the setSupplier
* method upon bundle activation (assuming one is present in the runtime), and subsequent
* calls will use the given supplier instance rather than the ServiceLoader.load.
*
* @param <S> the type of the supplier
* @param <R> the type of the supplier result/returned value
*/
public class McpServiceLoader<S extends Supplier<R>, R> {
private Class<S> supplierType;
private S supplier;
private R supplierResult;
public void setSupplier(S supplier) {
this.supplier = supplier;
this.supplierResult = null;
}
public void unsetSupplier(S supplier) {
this.supplier = null;
this.supplierResult = null;
}
public McpServiceLoader(Class<S> supplierType) {
this.supplierType = supplierType;
}
protected Optional<S> serviceLoad(Class<S> type) {
return ServiceLoader.load(type).findFirst();
}
@SuppressWarnings("unchecked")
public synchronized R getDefault() {
if (this.supplierResult == null) {
if (this.supplier == null) {
// Use serviceloader
Optional<?> sl = serviceLoad(this.supplierType);
if (sl.isEmpty()) {
throw new ServiceConfigurationError(
"No %s available for creating McpJsonMapper".formatted(this.supplierType.getSimpleName()));
}
this.supplier = (S) sl.get();
}
this.supplierResult = this.supplier.get();
}
return supplierResult;
}
}

9
mcp-core/src/main/resources/OSGI-INF/io.modelcontextprotocol.json.McpJsonDefaults.xml Normal file
View file

@ -0,0 +1,9 @@
<?xml version="1.0" encoding="UTF-8"?>
<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.3.0" name="io.modelcontextprotocol.json.McpJsonDefaults" immediate="true">
<service>
<provide interface="io.modelcontextprotocol.json.McpJsonDefaults"/>
</service>
<reference name="McpJsonMapperSupplier" interface="io.modelcontextprotocol.json.McpJsonMapperSupplier" bind="setMcpJsonMapperSupplier" unbind="unsetMcpJsonMapperSupplier"/>
<reference name="JsonSchemaValidatorSupplier" interface="io.modelcontextprotocol.json.schema.JsonSchemaValidatorSupplier" bind="setJsonSchemaValidatorSupplier" unbind="unsetJsonSchemaValidatorSupplier"/>
<implementation class="io.modelcontextprotocol.json.McpJsonDefaults"/>
</scr:component>

4
mcp-core/src/test/java/io/modelcontextprotocol/MockMcpClientTransport.java
View file

@ -9,7 +9,7 @@ import java.util.List;
import java.util.function.BiConsumer;
import java.util.function.Function;
import io.modelcontextprotocol.json.McpJsonMapper;
import io.modelcontextprotocol.json.McpJsonDefaults;
import io.modelcontextprotocol.json.TypeRef;
import io.modelcontextprotocol.spec.McpClientTransport;
import io.modelcontextprotocol.spec.McpSchema;
@ -100,7 +100,7 @@ public class MockMcpClientTransport implements McpClientTransport {
@Override
public <T> T unmarshalFrom(Object data, TypeRef<T> typeRef) {
return McpJsonMapper.getDefault().convertValue(data, typeRef);
return McpJsonDefaults.getDefaultMcpJsonMapper().convertValue(data, typeRef);
}
}

4
mcp-core/src/test/java/io/modelcontextprotocol/MockMcpServerTransport.java
View file

@ -8,7 +8,7 @@ import java.util.ArrayList;
import java.util.List;
import java.util.function.BiConsumer;
import io.modelcontextprotocol.json.McpJsonMapper;
import io.modelcontextprotocol.json.McpJsonDefaults;
import io.modelcontextprotocol.json.TypeRef;
import io.modelcontextprotocol.spec.McpSchema;
import io.modelcontextprotocol.spec.McpSchema.JSONRPCNotification;
@ -68,7 +68,7 @@ public class MockMcpServerTransport implements McpServerTransport {
@Override
public <T> T unmarshalFrom(Object data, TypeRef<T> typeRef) {
return McpJsonMapper.getDefault().convertValue(data, typeRef);
return McpJsonDefaults.getDefaultMcpJsonMapper().convertValue(data, typeRef);
}
}

3
mcp-core/src/test/java/io/modelcontextprotocol/spec/CompleteCompletionSerializationTest.java
View file

@ -1,5 +1,6 @@
package io.modelcontextprotocol.spec;
import io.modelcontextprotocol.json.McpJsonDefaults;
import io.modelcontextprotocol.json.McpJsonMapper;
import org.junit.jupiter.api.Test;
import java.io.IOException;
@ -10,7 +11,7 @@ class CompleteCompletionSerializationTest {
@Test
void codeCompletionSerialization() throws IOException {
McpJsonMapper jsonMapper = McpJsonMapper.getDefault();
McpJsonMapper jsonMapper = McpJsonDefaults.getDefaultMcpJsonMapper();
McpSchema.CompleteResult.CompleteCompletion codeComplete = new McpSchema.CompleteResult.CompleteCompletion(
Collections.emptyList(), 0, false);
String json = jsonMapper.writeValueAsString(codeComplete);

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