nested exception is com.fasterxm

今日份鸡汤：无论这个世界对你怎样，都请你一如既往的努力、勇敢、充满希望。

最近自己和身边的小伙伴都有一些事情发生，扰乱了思绪，也打破了自己安静学习的心，虽然到现在事情还没有结束，但是好在今天能够安静下来了，那就随便整理一些东西吧，今天这个简单

异常信息：
2021-12-16 11:15:34.983 WARN 19412 --- [nio-8080-exec-1] .w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Cannot construct instance of java.util.ArrayList (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('test'); nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of java.util.ArrayList (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('test')<LF> at [Source: (PushbackInputStream); line: 3, column: 9] (through reference chain: domain.User["list"])]

demo展示：

@RestController
@RequestMapping(value="/", params = {"Action"})
public class RequestMappingDemo {

    @RequestMapping(params = "Action=ParamTest")
    public User myParamTest(@RequestBody User user) {
        return user;
    }
}

@Data
public class User {

    private String name;

    private List<String> list;

    private int age;
}

postman请求：

image.png

从上图中不难看出，问题就出现在list参数值中，postman传进去的参数值类型与实际程序中的类型不一致导致的，那么更改一下重新访问一下就可以了:

image.png