NPE for MCP server

[voidmanun]

java.lang.NullPointerException: Cannot invoke "io.modelcontextprotocol.spec.McpServerSession.handle(io.modelcontextprotocol.spec.McpSchema$JSONRPCMessage)" because "session" is null

McpServerSession session = (McpServerSession)this.sessions.get(request.queryParam("sessionId").get());
the sessions is empty sometimes

[tzolov]

Thanks for reporting this problem @voidmanun It is an MCP Java SDK issue.
I guess it can happen if the server was restarted. Currently the MCP server implementation doesn't persist the session state so it can't recover ofter restart. But it should not throw NPE but proper exception. We will handle this issue on the sdk side.

[voidmanun]

Thanks for reporting this problem @voidmanun It is an MCP Java SDK issue. I guess it can happen if the server was restarted. Currently the MCP server implementation doesn't persist the session state so it can't recover ofter restart. But it should not throw NPE but proper exception. We will handle this issue on the sdk side.

ok,thanks for you reply