[Q/A][Java SDK (common)] Should the group version value be null and the empty string be treated the same?

[FoghostCn]

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• I am sure that all the content I provide is in English.

Apache Dubbo Component

Java SDK (apache/dubbo)

Details

Should the group version value be null and the empty string be treated the same? in dubbo java group and version default to null if not set, but in golang it default to empty string

this may cause compatiable issue,some logic depends on this, such as

dubbo/dubbo-common/src/main/java/org/apache/dubbo/common/ServiceKey.java

Lines 48 to 59 in cf53c38

	public boolean equals(Object o) {
	if (this == o) {
	return true;
	}
	if (o == null || getClass() != o.getClass()) {
	return false;
	}
	ServiceKey that = (ServiceKey) o;
	return Objects.equals(interfaceName, that.interfaceName)
	&& Objects.equals(group, that.group)
	&& Objects.equals(version, that.version);
	}

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[AlbumenJ]

They should be the same

[AlbumenJ]

Can you explain in which situation this will work as unexpected?

[FoghostCn]

this #13914

[AlbumenJ]

Actually, I don't know what is the relation about #13914 and #13915. 😭

[FoghostCn]

OK, Since #13914 has been solved, this matter is no longer important.

[AlbumenJ]

Do you mean #13932?

[FoghostCn]

Actually #13932 and #13914 are the same，they all refer to InstanceWrappedInvoker

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);

InstanceWrappedInvoker is used when org.apache.dubbo.common.ProtocolServiceKey#isSameWith is true, in #13932 and #13914 InstanceWrappedInvoker is used because group version value null and empty string is not the same in current implement

now we fixed InstanceWrappedInvoker in #13932, whatever InstanceWrappedInvoker is used or not it will no problems