Golang Gin-Gonic JSON绑定

Question

我有下面的结构

type foos struct { Foo string `json:"foo" binding:"required"`}

我有以下端点

  func sendFoo(c *gin.Context) {
      var json *foos

      if err := c.BindJSON(&json); err != nil {
          c.AbortWithStatus(400)
          return
      }

      // Do something about json
   }

当我发布这个JSON

{"bar":"bar bar"}

错误始终为零。 我写了必需的绑定，但是不起作用。 但是当我如下更改端点时，

func sendFoo(c *gin.Context) {
    var json foos //remove pointer

    if err := c.BindJSON(&json); err != nil {
          c.AbortWithStatus(400)
          return
    }

    // Do something about json
}

绑定有效并且错误不是nil。 为什么？

Answer 1

它记录在binding.go第25-32行中：

type StructValidator interface {
    // ValidateStruct can receive any kind of type and it should never panic, even if the configuration is not right.
    // If the received type is not a struct, any validation should be skipped and nil must be returned.
    // If the received type is a struct or pointer to a struct, the validation should be performed.
    // If the struct is not valid or the validation itself fails, a descriptive error should be returned.
    // Otherwise nil must be returned.
    ValidateStruct(interface{}) error
}

在您的情况下，ValidateStruct会收到一个指向结构的指针，并且如文档所述，不会进行任何检查。