[Bug] org.apache.dubbo.rpc.protocol.dubbo.FutureAdapter cannot be cast to org.apache.dubbo.samples.proto.GreetService

[Yoda-wu]

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Apache Dubbo Component

Java SDK (apache/dubbo)

Dubbo Version

operating system: ubuntu 22.04.1
dubbo-java-client :Dubbo: 3.3.0-beta.1; Java: 1.8
dubbo-go-server: Dubbo-go: 3.2.0; go 1.22.0

Steps to reproduce this issue

bug_demo_repo: https://github.com/Yoda-wu/dubbo-go-samples/tree/bug_demo/service_discovery/service/go-server

1. start the nacos server
2. start the go-server:go run server.go
3. start the java-client:

cd ../java-client 
mvn -e clean compile exec:java -Dexec.mainClass="org.apache.dubbo.samples.Main"

then:

What you expected to happen

i expect in java-client, it will receive GreetResponse from go-server

Anything else

No response

Are you willing to submit a pull request to fix on your own?

• Yes I am willing to submit a pull request on my own!

Code of Conduct

• I agree to follow this project's Code of Conduct

[AlbumenJ]

@EarthChen @icodening PTAL

[AlbumenJ]

@Yoda-wu Have you tried with 3.2.11?

[FoghostCn]

3.2.11 is OK

[FoghostCn]

dubbo/dubbo-registry/dubbo-registry-api/src/main/java/org/apache/dubbo/registry/client/ServiceDiscoveryRegistryDirectory.java

Lines 776 to 794 in cf53c38

	public Result invoke(Invocation invocation) throws RpcException {
	// override consumer url with real protocol service key
	RpcContext.getServiceContext().setConsumerUrl(newConsumerUrl);
	// recreate invocation due to the protocol service key changed
	RpcInvocation copiedInvocation = new RpcInvocation(
	invocation.getTargetServiceUniqueName(),
	invocation.getServiceModel(),
	invocation.getMethodName(),
	invocation.getServiceName(),
	protocolServiceKey.toString(),
	invocation.getParameterTypes(),
	invocation.getArguments(),
	invocation.getObjectAttachments(),
	invocation.getInvoker(),
	invocation.getAttributes(),
	invocation instanceof RpcInvocation ? ((RpcInvocation) invocation).getInvokeMode() : null);
	copiedInvocation.setObjectAttachment(CommonConstants.GROUP_KEY, protocolServiceKey.getGroup());
	copiedInvocation.setObjectAttachment(CommonConstants.VERSION_KEY, protocolServiceKey.getVersion());
	return originInvoker.invoke(copiedInvocation);

the copiedInvocation has different returnType with origin invocation,it should be GreetResponse but actually it is CompletableFuture

finally return a Future to user:

dubbo/dubbo-rpc/dubbo-rpc-api/src/main/java/org/apache/dubbo/rpc/AsyncRpcResult.java

Lines 238 to 246 in cf53c38

	public Object recreate() throws Throwable {
	RpcInvocation rpcInvocation = (RpcInvocation) invocation;
	if (InvokeMode.FUTURE == rpcInvocation.getInvokeMode()) {
	return RpcContext.getClientAttachment().getFuture();
	} else if (InvokeMode.ASYNC == rpcInvocation.getInvokeMode()) {
	return createDefaultValue(invocation).recreate();
	}
	return getAppResponse().recreate();

[AlbumenJ]

Can you please create a new issue based on this consequence and submit a PR to fix it?

[FoghostCn]

OK，I'll fix it soon

[FoghostCn]

I found it was already fixd in #13582 in 3.3.0-beta.2-SNAPSHOT

[FoghostCn]

There are still some problems, and errors will still be reported when using asynchronous methods.

CompletableFuture<GreetResponse> future = greetService.greetAsync(req);
GreetResponse greet = future.get();

Exception in thread "main" java.lang.ClassCastException: org.apache.dubbo.samples.proto.GreetResponse cannot be cast to java.util.concurrent.CompletableFuture
	at org.apache.dubbo.samples.proto.DubboGreetServiceTriple$GreetServiceStub.greetAsync(DubboGreetServiceTriple.java:117)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.dubbo.config.spring.util.LazyTargetInvocationHandler.invoke(LazyTargetInvocationHandler.java:54)
	at org.apache.dubbo.samples.proto.GreetServiceDubboProxy0.greetAsync(GreetServiceDubboProxy0.java)
	at org.apache.dubbo.samples.Main.main(Main.java:26)

code is at:
https://github.com/FoghostCn/dubbo-go-samples/blob/async-bug/service_discovery/service/java-client/src/main/java/org/apache/dubbo/samples/Main.java

I have opened a new issue #13931