Add mcp-sdk-plain module: MCP server on the plain Java SDK 2.1.0 over stdio and Streamable HTTP, fat jar, wire transcripts and a Spring AI client

Co-Authored-By: Claude Sonnet 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_017ic4b5oh78z7gcH6QkxafF
2026-11-08 18:28:07 +00:00
parent 7c20ea1370
commit 58eaf4c2e1
29 changed files with 864 additions and 0 deletions
@@ -0,0 +1,29 @@
+server: notes-server 1.0.0
+protocol: 2025-11-25
+capabilities: tools=true resources=true prompts=false
+instructions: Tools: word_stats, divide, explode. Resources: notes://readme and notes://{name}.
+-- tools/list
+word_stats required=[text]
+divide required=[a, b]
+explode required=null
+-- tools/call word_stats
+isError=false text=words=4 chars=19 longest=quick
+-- tools/call divide 1/0
+isError=true text=Cannot divide 1.0 by zero.
+-- tools/call word_stats with a missing argument
+isError=true text=Tool (word_stats) input validation failed: Validation failed: JSON schema validation errors: [: required property 'text' not found]
+-- tools/call explode
+threw McpError: boom from the handler
+-- resources/list
+notes://readme text/markdown
+-- resources/templates/list
+notes://{name}
+-- resources/read notes://readme
+# Notes server
+Built with the plain MCP Java SDK.
+-- resources/read notes://todo
+1. Write the post
+2. Run the server
+3. Publish
+-- resources/read notes://missing
+threw McpError: No note called missing
@@ -0,0 +1,29 @@
+server: notes-server 1.0.0
+protocol: 2025-11-25
+capabilities: tools=true resources=true prompts=false
+instructions: Tools: word_stats, divide, explode. Resources: notes://readme and notes://{name}.
+-- tools/list
+word_stats required=[text]
+divide required=[a, b]
+explode required=null
+-- tools/call word_stats
+isError=false text=words=4 chars=19 longest=quick
+-- tools/call divide 1/0
+isError=true text=Cannot divide 1.0 by zero.
+-- tools/call word_stats with a missing argument
+isError=true text=Tool (word_stats) input validation failed: Validation failed: JSON schema validation errors: [: required property 'text' not found]
+-- tools/call explode
+threw McpError: boom from the handler
+-- resources/list
+notes://readme text/markdown
+-- resources/templates/list
+notes://{name}
+-- resources/read notes://readme
+# Notes server
+Built with the plain MCP Java SDK.
+-- resources/read notes://todo
+1. Write the post
+2. Run the server
+3. Publish
+-- resources/read notes://missing
+threw McpError: No note called missing
@@ -0,0 +1,19 @@
+-- POST initialize, Accept: application/json, text/event-stream
+status 200
+content-type application/json;charset=utf-8
+mcp-session-id present: true
+body: {"jsonrpc":"2.0","id":1,"result":{"protocolVersion":"2025-06-18","capabilities":{"logging":{},"resources":{"subscribe":false,"listChanged":true},"tools":{"listChanged":true}},"serverInfo":{"name":"notes-server","version":"1.0.0"},"instructions":"Tools: word_stats, divide, explode. Resources: notes://readme and notes://{name}."}}
+-- POST tools/list without the Mcp-Session-Id header
+status 400
+jsonRpcError: {"code":-32601,"message":"Session ID required in mcp-session-id header"}
+body also contains a Java stackTrace: true
+-- POST initialize with Accept: application/json only
+status 400
+jsonRpcError: {"code":-32601,"message":"text/event-stream required in Accept header"}
+body also contains a Java stackTrace: true
+-- DELETE with the session id ends the session
+status 200
+-- POST tools/list on the ended session
+status 404
+jsonRpcError: {"code":-32603,"message":"Session not found: <session-id>"}
+body also contains a Java stackTrace: true
@@ -0,0 +1,2 @@
+client failed: RuntimeException: Client failed to initialize by explicit API call
+  caused by TimeoutException: Did not observe any item or terminal signal within 20000ms in 'map' (and no fallback has been configured)
@@ -0,0 +1,3 @@
+$ printf <3 JSON-RPC lines> | java -jar target/mcp-sdk-plain.jar stdio
+{"jsonrpc":"2.0","id":1,"result":{"protocolVersion":"2025-06-18","capabilities":{"logging":{},"resources":{"subscribe":false,"listChanged":true},"tools":{"listChanged":true}},"serverInfo":{"name":"notes-server","version":"1.0.0"},"instructions":"Tools: word_stats, divide, explode. Resources: notes://readme and notes://{name}."}}
+{"jsonrpc":"2.0","id":2,"result":{"content":[{"type":"text","text":"words=3 chars=13 longest=three"}],"isError":false}}
@@ -0,0 +1,14 @@
+$ curl -i -X POST http://127.0.0.1:18089/mcp  (initialize)
+HTTP/1.1 200 OK
+Content-Type: application/json;charset=utf-8
+Mcp-Session-Id: <session-id>
+Transfer-Encoding: chunked
+
+{"jsonrpc":"2.0","id":1,"result":{"protocolVersion":"2025-06-18","capabilities":{"logging":{},"resources":{"subscribe":false,"listChanged":true},"tools":{"listChanged":true}},"serverInfo":{"name":"notes-server","version":"1.0.0"},"instructions":"Tools: word_stats, divide, explode. Resources: notes://readme and notes://{name}."}}
+
+$ curl -X POST http://127.0.0.1:18089/mcp -H 'Mcp-Session-Id: <session-id>'  (tools/call word_stats)
+id: a76ab1b0-cb40-43f2-9d82-db0fa6c7f29c
+event: message
+data: {"jsonrpc":"2.0","id":2,"result":{"content":[{"type":"text","text":"words=3 chars=13 longest=three"}],"isError":false}}
+
+
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+clients: 1
+server: notes-server 1.0.0
+tool: word_stats
+tool: divide
+tool: explode
+word_stats -> words=5 chars=25 longest=spring