Java异常之----Caused by: java.lang.IllegalStateException: Method has too many Body parameters

1、错误信息

异常：Caused by: java.lang.IllegalStateException: Method has too many Body parameters

Caused by: java.lang.IllegalStateException: Method has too many Body parameters: public abstract com.iot.framework.core.response.CommResponse 
com.iot.basic.config.api.client.configdata.PushRuleClient.getByEventId(java.lang.String,java.lang.String)
	at feign.Util.checkState(Util.java:127)
	at feign.Contract$BaseContract.parseAndValidateMetadata(Contract.java:117)
	at org.springframework.cloud.openfeign.support.SpringMvcContract.parseAndValidateMetadata(SpringMvcContract.java:188)
	at feign.Contract$BaseContract.parseAndValidatateMetadata(Contract.java:66)
	at feign.hystrix.HystrixDelegatingContract.parseAndValidatateMetadata(HystrixDelegatingContract.java:46)
	at feign.ReflectiveFeign$ParseHandlersByName.apply(ReflectiveFeign.java:154)
	at feign.ReflectiveFeign.newInstance(ReflectiveFeign.java:52)
	at feign.Feign$Builder.target(Feign.java:251)
	at org.springframework.cloud.openfeign.HystrixTargeter.target(HystrixTargeter.java:55)
	at org.springframework.cloud.openfeign.FeignClientFactoryBean.loadBalance(FeignClientFactoryBean.java:238)
	at org.springframework.cloud.openfeign.FeignClientFactoryBean.getTarget(FeignClientFactoryBean.java:267)
	at org.springframework.cloud.openfeign.FeignClientFactoryBean.getObject(FeignClientFactoryBean.java:247)
	at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.doGetObjectFromFactoryBean(FactoryBeanRegistrySupport.java:171)
	... 43 common frames omitted

2、错误原因

报错信息翻译过来就是：方法有太多的Body参数。根据错误提示信息，可以看到具体的是哪个方法，然后找到对应的方法，查看参数是否有误，当通过Feign客户端调用其他服务的接口时，请求参数可以有多个，用spring自带的注解用的方式不对，所以才导致报错。在同一个方法参数位置，@RequestParam注解可以用多个，但是@RequestBody注解只能用一个。

以下是我项目里用的方式，String devModel, String eventId这两个参数没有用@RequestParam注解说明，导致上述报错。

@ApiOperation("根据模型事件查询消息规则")
@RequestMapping(value = "/pushRule/getByEventId",method = RequestMethod.GET)
public CommResponse<List<PushRuleResponse>> getByEventId(String devModel, String eventId);

3、解决方案

解决方法其实很简单，在方法的参数上加上@RequestParam注解（同时可以用多个）即可。这里有两个参数，加上两个@RequestParam注解。如果有一个对象参数是要用@RequestBody注解的（这个注解同时只能用一个）。

@ApiOperation("根据模型事件查询推送规则")
@RequestMapping(value = "/pushRule/getByEventId",method = RequestMethod.GET)
public CommResponse<List<PushRuleResponse>> getByEventId(@RequestParam String devModel, @RequestParam String eventId);