Duplicate Config found for ApplicationConfig

[yintiefu]

Environment

• Dubbo version: 2.7.2
• Java version: 1.8

Steps to reproduce this issue

一个API网关的应用，即是服务提供者，也是消费者，消费是dubbo泛化调用，从2.6 升级到2.7.2之后，服务启动报错 Duplicate Config found for ApplicationConfig

       ApplicationConfig applicationConfig = new ApplicationConfig();
        applicationConfig.setName("generic-call-consumer");
        RegistryConfig registryConfig = new RegistryConfig();
        registryConfig.setAddress("zookeeper://127.0.0.1:2181");
        ReferenceConfig<GenericService> referenceConfig = new ReferenceConfig<>();
        referenceConfig.setInterface("org.apache.dubbo.samples.generic.call.api.HelloService");
        //会报错 
        applicationConfig.setRegistry(registryConfig);
        referenceConfig.setApplication(applicationConfig);
        referenceConfig.setGeneric(true);
        referenceConfig.setAsync(true);
        referenceConfig.setTimeout(7000);

主要原因是 2.7.x之后 referenceConfig.setApplication添加了校验逻辑 checkDuplicate

    public void setApplication(ApplicationConfig application) {
        if (application != null) {
            checkDuplicate(this.application, application);
            this.application = application;
        }
    }
      private void checkDuplicate(AbstractConfig oldOne, AbstractConfig newOne) {
        if (oldOne != null && !oldOne.equals(newOne)) {
            String configName = oldOne.getClass().getSimpleName();
            throw new IllegalStateException("Duplicate Config found for " + configName + ", you 
            should use only one unique " + configName + " for one application.");
        }
    }

针对这种情况要怎么处理？

[jimgreat]

这里不用 referenceConfig.setApplication(applicationConfig); 应该就可以了

[chickenlj]

你可以在任何地方调用setApplication()，前提是ApplicationConfig指向同一个实例。

[hengyunabc]

这个提示不清晰，比如用户有两个xml，一个配置了

<dubbo:application name="StafeTest" />

另一个配置了

<dubbo:application name="dubboProviderApplication" />

启动就会报错。

建议改为打印提示日志，并且提示信息更清晰点。