在请求体上获取整数

Question

需要获取要在数据库上删除的 id 但我无法通过这种方式获取 id 参数

@RequestMapping(value = {"/delete/search/","/delete/search"}, method = RequestMethod.DELETE)
    @ResponseBody
    public Integer deleteUser(@RequestBody Integer id_search) {
        return id_search;
    }

我收到此错误消息

"message": "JSON parse error: Can not deserialize instance of java.lang.Integer out of START_OBJECT token; nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not deserialize instance of java.lang.Integer out of START_OBJECT token\n at [Source: java.io.PushbackInputStream@1b77938; line: 1, column

Answer 1

这个说法是错误的

@RequestBody Integer id_search

这意味着 Spring 需要一个类型Integer类的主体。但是您作为主体传递的内容与 Integer 类不匹配。

您有多种选择来解决此问题。

1. 删除@RequestBody并声明为

   public Integer deleteUser(Integer id_search) {...}
   

   有了这个，您需要将此端点称为

   http://localhost:8080/seviceRS/delete/search?id_search=2
   

2. PathVariable你可以像这样 传递它

   http://localhost:8080/seviceRS/delete/search/2
   

   为此，请像这样更改控制器方法

   @RequestMapping(value = 
   {"/delete/search/{id_search}"}, method = 
                                          RequestMethod.DELETE)
     @ResponseBody
     public Integer deleteUser(Integer id_search) {...}
   

3. 如果您想作为正文发送，那么您应该创建一个与您发送的 json 匹配的类。

   例如。创建一个类似的类

    class Demo {
     private int id_search;
     //Getters & Setters
    }
   

   通过这种方法，您的控制器方法看起来像

   @RequestMapping(value = {"/delete/search/}, method = 
                     RequestMethod.DELETE)
   @ResponseBody
   public Integer deleteUser(Demo demo) {
        demo.getId_Search();
   }
   

Answer 2

Perhaps you are trying to send a request with JSON text in its body from a Postman client or something similar like this:

{
 "id_search":2
}

This cannot be deserialized by Jackson since this is not an Integer (it seems to be, but it isn't). An Integer object from java.lang Integer is a little more complex.

For your Postman request to work, simply put (without curly braces { }):

2