[3.3] Adapt MCP integration to sdk 0.18.2 APIs

[zrlw]

What is the purpose of the change?

Adapt MCP integration to sdk 0.18.2 APIs

Checklist

• Make sure there is a GitHub_issue field for the change.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• Write necessary unit-test to verify your logic correction. If the new feature or significant change is committed, please remember to add sample in dubbo samples project.
• Make sure gitHub actions can pass. Why the workflow is failing and how to fix it?

[codecov-commenter]

Codecov Report

❌ Patch coverage is 76.19048% with 10 lines in your changes missing coverage. Please review.
✅ Project coverage is 60.79%. Comparing base (6916d1b) to head (85d80e2).

Files with missing lines	Patch %	Lines
...transport/DubboMcpStreamableTransportProvider.java	53.84%	6 Missing ⚠️
...bo/mcp/transport/DubboMcpSseTransportProvider.java	75.00%	2 Missing ⚠️
...e/dubbo/mcp/core/McpApplicationDeployListener.java	80.00%	1 Missing ⚠️
...pache/dubbo/mcp/tool/DubboServiceToolRegistry.java	87.50%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##                3.3   #16267      +/-   ##
============================================
+ Coverage     60.78%   60.79%   +0.01%     
+ Complexity    11763    11762       -1     
============================================
  Files          1953     1953              
  Lines         89186    89181       -5     
  Branches      13454    13454              
============================================
+ Hits          54209    54218       +9     
+ Misses        29400    29386      -14     
  Partials       5577     5577              

Flag	Coverage Δ
integration-tests-java21	32.16% <0.00%> (+<0.01%)	⬆️
integration-tests-java8	32.32% <0.00%> (+0.09%)	⬆️
samples-tests-java21	32.19% <0.00%> (+<0.01%)	⬆️
samples-tests-java8	29.85% <0.00%> (+0.04%)	⬆️
unit-tests-java11	59.04% <ø> (+0.02%)	⬆️
unit-tests-java17	58.50% <76.19%> (-0.01%)	⬇️
unit-tests-java21	58.56% <76.19%> (+0.05%)	⬆️
unit-tests-java25	58.46% <76.19%> (+<0.01%)	⬆️
unit-tests-java8	58.99% <ø> (-0.03%)	⬇️

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[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adapts the Dubbo MCP integration to the Model Context Protocol SDK 0.18.2 API changes (JSON mapping, schema/tool representations).

Changes:

• Bumps MCP SDK dependency from 0.11.2 to 0.18.2.
• Migrates transports to use McpJsonMapper/TypeRef instead of Jackson ObjectMapper/TypeReference.
• Updates tool/schema construction to use McpSchema.Tool.builder() and McpSchema.JsonSchema (and adjusts tests accordingly).

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
dubbo-plugin/dubbo-mcp/pom.xml	Bumps MCP SDK version to 0.18.2.
dubbo-plugin/dubbo-mcp/src/main/java/org/apache/dubbo/mcp/core/McpApplicationDeployListener.java	Wires JacksonMcpJsonMapper into transport providers.
dubbo-plugin/dubbo-mcp/src/main/java/org/apache/dubbo/mcp/transport/DubboMcpStreamableTransportProvider.java	Switches JSON handling to McpJsonMapper/TypeRef and updates init parsing.
dubbo-plugin/dubbo-mcp/src/main/java/org/apache/dubbo/mcp/transport/DubboMcpSseTransportProvider.java	Switches JSON handling to McpJsonMapper/TypeRef.
dubbo-plugin/dubbo-mcp/src/main/java/org/apache/dubbo/mcp/tool/DubboServiceToolRegistry.java	Builds tools via builder and returns JsonSchema objects instead of JSON strings.
dubbo-plugin/dubbo-mcp/src/main/java/org/apache/dubbo/mcp/tool/DubboOpenApiToolConverter.java	Builds tools via builder and returns JsonSchema objects instead of JSON strings.
dubbo-plugin/dubbo-mcp/src/test/java/org/apache/dubbo/mcp/transport/DubboMcpStreamableTransportProviderTest.java	Updates tests to pass JacksonMcpJsonMapper.
dubbo-plugin/dubbo-mcp/src/test/java/org/apache/dubbo/mcp/transport/DubboMcpSseTransportProviderTest.java	Updates tests to pass JacksonMcpJsonMapper.
dubbo-plugin/dubbo-mcp/src/test/java/org/apache/dubbo/mcp/tool/DubboServiceToolRegistryTest.java	Updates tests to use Tool.builder() + JsonSchema.

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[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (1)

dubbo-plugin/dubbo-mcp/src/main/java/org/apache/dubbo/mcp/transport/DubboMcpSseTransportProvider.java:80

• The public constructors now require McpJsonMapper, which is a source/binary breaking change for any external code instantiating this transport provider. If backward compatibility is a goal for the 3.3 line, consider keeping an overload that accepts a Jackson ObjectMapper (deprecated) and wraps it with JacksonMcpJsonMapper internally.

    public DubboMcpSseTransportProvider(McpJsonMapper mcpJsonMapper, Integer expireSeconds) {
        if (expireSeconds != null) {
            if (expireSeconds < 60) {
                expireSeconds = 60;
            }

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (2)

dubbo-plugin/dubbo-mcp/src/main/java/org/apache/dubbo/mcp/transport/DubboMcpStreamableTransportProvider.java:562

• In this sendMessage(...) implementation you guard responseObserver for onNext, but the catch path below still calls responseObserver.onError(e) unconditionally. If responseObserver is null (which this method already anticipates), this will throw an NPE and mask the original error. Please null-check before calling onError/onCompleted, or return a Mono.error(...) so the error is propagated without dereferencing a null observer.

                        String jsonText = mcpJsonMapper.writeValueAsString(message);
                        responseObserver.onNext(ServerSentEvent.<byte[]>builder()
                                .event("message")
                                .data(jsonText.getBytes(StandardCharsets.UTF_8))
                                .build());

dubbo-plugin/dubbo-mcp/src/main/java/org/apache/dubbo/mcp/transport/DubboMcpStreamableTransportProvider.java:580

• Same issue as the other overload: responseObserver is checked before onNext, but the catch path calls responseObserver.onError(e) without a null check. If responseObserver can be null, this will throw NPE during error handling. Please guard onError similarly or propagate errors via Mono.error(...).

                        String jsonText = mcpJsonMapper.writeValueAsString(message);
                        ServerSentEvent<byte[]> event = ServerSentEvent.<byte[]>builder()
                                .event("message")
                                .data(jsonText.getBytes(StandardCharsets.UTF_8))
                                .id(messageId)
                                .build();