modelcontextprotocol/java-sdk
Watch
1
0
Fork
You've already forked java-sdk
 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

feat: implement ping request handler in MCP async client (#203)

Browse source 
- Add ping request handler that responds with empty Map instead of null
- Ensure compliance with MCP protocol requirement for ping responses
- Add test for ping message request handling

Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
This commit is contained in:
or-givati 2025-03-24 14:41:07 +02:00 • committed by Christian Tzolov
commit ebb9764c1b
2 changed files with 30 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

3
mcp/src/main/java/io/modelcontextprotocol/client/McpAsyncClient.java
View file

@ -187,6 +187,9 @@ public class McpAsyncClient {
// Request Handlers
Map<String, RequestHandler<?>> requestHandlers = new HashMap<>();
// Ping MUST respond with an empty data, but not NULL response.
requestHandlers.put(McpSchema.METHOD_PING, params -> Mono.just(Map.of()));
// Roots List Request Handler
if (this.clientCapabilities.roots() != null) {
requestHandlers.put(McpSchema.METHOD_ROOTS_LIST, rootsListRequestHandler());

28
mcp/src/test/java/io/modelcontextprotocol/client/McpAsyncClientResponseHandlerTests.java
View file

@ -525,4 +525,30 @@ class McpAsyncClientResponseHandlerTests {
.hasMessage("Elicitation handler must not be null when client capabilities include elicitation");
}
}
@Test
void testPingMessageRequestHandling() {
MockMcpClientTransport transport = initializationEnabledTransport();
McpAsyncClient asyncMcpClient = McpClient.async(transport).build();
assertThat(asyncMcpClient.initialize().block()).isNotNull();
// Simulate incoming ping request from server
McpSchema.JSONRPCRequest pingRequest = new McpSchema.JSONRPCRequest(McpSchema.JSONRPC_VERSION,
McpSchema.METHOD_PING, "ping-id", null);
transport.simulateIncomingMessage(pingRequest);
// Verify response
McpSchema.JSONRPCMessage sentMessage = transport.getLastSentMessage();
assertThat(sentMessage).isInstanceOf(McpSchema.JSONRPCResponse.class);
McpSchema.JSONRPCResponse response = (McpSchema.JSONRPCResponse) sentMessage;
assertThat(response.id()).isEqualTo("ping-id");
assertThat(response.error()).isNull();
assertThat(response.result()).isInstanceOf(Map.class);
assertThat(((Map<?, ?>) response.result())).isEmpty();
asyncMcpClient.closeGracefully();
}
}