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refactor: consolidate MCP client initialization logic #334

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refactor: consolidate MCP client initialization logic #334

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20 changes: 11 additions & 9 deletions mcp/src/main/java/io/modelcontextprotocol/client/McpAsyncClient.java
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Original file line number Diff line number Diff line change
Expand Up @@ -387,7 +387,12 @@ public Mono<McpSchema.InitializeResult> initialize() {
return withSession("by explicit API call", init -> Mono.just(init.get()));
}

private Mono<McpSchema.InitializeResult> doInitialize(McpClientSession mcpClientSession) {
private Mono<McpSchema.InitializeResult> doInitialize(Initialization initializaiton) {
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Typo in "initializaiton" -> should be initialization.


initializaiton.setMcpClientSession(this.sessionSupplier.get());

McpClientSession mcpClientSession = initializaiton.mcpSession();

String latestVersion = this.protocolVersions.get(this.protocolVersions.size() - 1);

McpSchema.InitializeRequest initializeRequest = new McpSchema.InitializeRequest(// @formatter:off
Expand All @@ -410,6 +415,9 @@ private Mono<McpSchema.InitializeResult> doInitialize(McpClientSession mcpClient

return mcpClientSession.sendNotification(McpSchema.METHOD_NOTIFICATION_INITIALIZED, null)
.thenReturn(initializeResult);
}).doOnNext(initializaiton::complete).onErrorResume(ex -> {
initializaiton.error(ex);
return Mono.error(ex);
});
}

Expand Down Expand Up @@ -477,15 +485,9 @@ private <T> Mono<T> withSession(String actionName, Function<Initialization, Mono

boolean needsToInitialize = previous == null;
logger.debug(needsToInitialize ? "Initialization process started" : "Joining previous initialization");
if (needsToInitialize) {
newInit.setMcpClientSession(this.sessionSupplier.get());
}

Mono<McpSchema.InitializeResult> initializationJob = needsToInitialize
? doInitialize(newInit.mcpSession()).doOnNext(newInit::complete).onErrorResume(ex -> {
newInit.error(ex);
return Mono.error(ex);
}) : previous.await();
Mono<McpSchema.InitializeResult> initializationJob = needsToInitialize ? doInitialize(newInit)
: previous.await();

return initializationJob.map(initializeResult -> this.initializationRef.get())
.timeout(this.initializationTimeout)
Expand Down
14 changes: 7 additions & 7 deletions mcp/src/main/java/io/modelcontextprotocol/spec/McpClientSession.java
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Expand Up @@ -229,27 +229,27 @@ private String generateRequestId() {
public <T> Mono<T> sendRequest(String method, Object requestParams, TypeReference<T> typeRef) {
String requestId = this.generateRequestId();

return Mono.deferContextual(ctx -> Mono.<McpSchema.JSONRPCResponse>create(sink -> {
return Mono.deferContextual(ctx -> Mono.<McpSchema.JSONRPCResponse>create(responseSink -> {
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responseSink vs resultSink still feel quite similar. I have a different proposal.
Sink from Mono.create shall be called pendingResponseSink.
Sink for handle operator shall be called deliveredResponseSink.
WDYT?

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I like it

logger.debug("Sending message for method {}", method);
this.pendingResponses.put(requestId, sink);
this.pendingResponses.put(requestId, responseSink);
McpSchema.JSONRPCRequest jsonrpcRequest = new McpSchema.JSONRPCRequest(McpSchema.JSONRPC_VERSION, method,
requestId, requestParams);
this.transport.sendMessage(jsonrpcRequest).contextWrite(ctx).subscribe(v -> {
}, error -> {
this.pendingResponses.remove(requestId);
sink.error(error);
responseSink.error(error);
});
})).timeout(this.requestTimeout).handle((jsonRpcResponse, sink) -> {
})).timeout(this.requestTimeout).handle((jsonRpcResponse, resultSink) -> {
if (jsonRpcResponse.error() != null) {
logger.error("Error handling request: {}", jsonRpcResponse.error());
sink.error(new McpError(jsonRpcResponse.error()));
resultSink.error(new McpError(jsonRpcResponse.error()));
}
else {
if (typeRef.getType().equals(Void.class)) {
sink.complete();
resultSink.complete();
}
else {
sink.next(this.transport.unmarshalFrom(jsonRpcResponse.result(), typeRef));
resultSink.next(this.transport.unmarshalFrom(jsonRpcResponse.result(), typeRef));
}
}
});
Expand Down