Error "There is already 'XXX' bean method" when the kotlin springmvc project runs

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1. Problems

There is a controller class in the project with a searchById method, where isLocal is a boolean parameter with a default value of false, which is used to determine whether to connect to a local or online database.

 1 @Controller
 2 @RequestMapping("api/case_info")
 3 class DocEditAction {
 4     ……
 5 
 6     @ResponseBody
 7     @RequestMapping(value = ["search"], method = [RequestMethod.GET])
 8     fun searchById(id: String, isLocal: Boolean = false): AnalyzeJson {
 9     　　…………
10     }    
11 
12 }

When the project is packaged as a war package and placed on tomcat, an error is reported. The error message is as follows:

public final XXX.AnalyzeJson XXX.DocEditAction.searchById(java.lang.String,boolean)
to {[/api/case_info/search],methods=[GET]}: There is already 'docEditAction' bean method
public static XXX.AnalyzeJson XXX.DocEditAction.searchById$default(XXX.DocEditAction,java.lang.String,boolean,int,java.lang.Object) mapped.
15:24:41 [http-nio-8660-exec-1] ERROR org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:502)- Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'requestMappingHandlerMapping' defined in org.springframework.web.servlet.config.annotation.DelegatingWebMvcConfiguration: Invocation of init method failed; nested exception is java.lang.IllegalStateException: Ambiguous mapping. Cannot map 'docEditAction' method 
public final XXX.AnalyzeJson XXX.DocEditAction.searchById(java.lang.String,boolean)
to {[/api/case_info/search],methods=[GET]}: There is already 'docEditAction' bean method

The strange thing is that there are several methods with default parameters in such a controller, and no errors have been reported before. Possible related changes that occurred during this period are:

1. An old brother wrote an interceptor to process all the received requests, "requestMappingHandlerMapping" is a newly added bean

2. The kotlin version has been upgraded from 1.2.30 to 1.2.40

 

Two, the cause

I haven't found the root cause. It is speculated that there is a problem with the interceptor written by my brother.

 

3. Solutions

Write the parameters with default values ​​in the method in the method, and then repackage them and throw them into tomcat to start without reporting an error.

Although it doesn't seem to solve the underlying problem.