【随手记录】关于feign报UnsupportedOperationException错误

 

前几天同事使用feign调API的时候报错：

java.lang.UnsupportedOperationException
at java.util.Collections$UnmodifiableCollection.add(Collections.java:1055)
at org.springframework.cloud.openfeign.support.FeignUtils.addTemplateParameter(FeignUtils.java:60)
at org.springframework.cloud.openfeign.support.SpringMvcContract$SimpleAnnotatedParameterContext.setTemplateParameter(SpringMvcContract.java:460)
at org.springframework.cloud.openfeign.annotation.RequestParamParameterProcessor.processArgument(RequestParamParameterProcessor.java:69)
at org.springframework.cloud.openfeign.support.SpringMvcContract.processAnnotationsOnParameter(SpringMvcContract.java:292)
at feign.Contract$BaseContract.parseAndValidateMetadata(Contract.java:110)
at org.springframework.cloud.openfeign.support.SpringMvcContract.parseAndValidateMetadata(SpringMvcContract.java:188)
at feign.Contract$BaseContract.parseAndValidatateMetadata(Contract.java:66)
at feign.ReflectiveFeign$ParseHandlersByName.apply(ReflectiveFeign.java:154)
at feign.ReflectiveFeign.newInstance(ReflectiveFeign.java:52)
at feign.Feign$Builder.target(Feign.java:251)
at feign.Feign$Builder.target(Feign.java:247)
at com.supermap.sinfcloud.common.feign.FeignService.newWebApiByName(FeignService.java:81)
at com.supermap.sinfcloud.common.feign.FeignService.newWebApiByName(FeignService.java:71)

原因就是在处理feign API参数时候，参数名称出现多个重复的，就会导致feign处理参数出错！

@GetMapping("/test")
Message<?> apply(@RequestParam("userName") String userName,@RequestParam("userName") String userId);

 还是少拷贝，仔细点好~