将结构体作为字符串存储在Redis中。

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英文:

Store struct as string in redis

问题

Redis只能存储字符串,我想知道如何在Go语言中实现类似于JavaScript的JSON.stringify的功能,将结构体转换为字符串。

我尝试了类型转换:

string(结构体)

但是这会导致错误。

英文:

As Redis only stores strings I would like to know how I can do the equivalent of Javascript's JSON.stringify using Go to convert a Struct into a string.

I have tried typecasting:

string(the_struct)

but this results in an error.

答案1

得分: 0

encoding/json 包可以用于将 struct 转换为 JSON 字符串,反之亦然(将 JSON 字符串解析为 struct)。

简单示例(在 Go Playground 上尝试):

type Person struct {
    Name string
    Age  int
}

func main() {
    p := Person{"Bob", 23}

    // Struct -> JSON
    data, err := json.Marshal(&p)
    if err != nil {
        panic(err)
    }
    fmt.Println(string(data))

    // JSON -> Struct
    var p2 Person
    err = json.Unmarshal(data, &p2)
    if err != nil {
        panic(err)
    }
    fmt.Printf("%+v", p2)
}

输出:

{"Name":"Bob","Age":23}
{Name:Bob Age:23}

注意事项:###

struct 的字段必须是公开的(以大写字母开头),否则 json 包(使用反射)将无法读取/写入它们。

您还可以为结构字段指定标签,以控制/微调 JSON 编组/解组过程,例如更改 JSON 文本中的名称:

type Person struct {
    Name string `json:"name"`
    Age  int    `json:"years"`
}

通过这个更改,上述应用程序的输出如下:

{"name":"Bob","years":23}
{Name:Bob Age:23}

json.Marshal() 函数的文档详细介绍了标签提供的可能性。

通过实现 json.Marshalerjson.Unmarshaler 接口,您可以完全自定义编组/解组过程。

此外,如果您的结构体没有预定义(例如,您事先不知道字段),可以使用 map[string]interface{}请参阅此答案以获取详细信息和示例

英文:

The encoding/json package can be used to easily convert a struct to JSON string and vice versa (parse a JSON string into a struct).

Simple example (try it on the Go Playground):

type Person struct {
	Name string
	Age  int
}

func main() {
	p := Person{"Bob", 23}

	// Struct -> JSON
	data, err := json.Marshal(&p)
	if err != nil {
		panic(err)
	}
	fmt.Println(string(data))

	// JSON -> JSON
	var p2 Person
	err = json.Unmarshal(data, &p2)
	if err != nil {
		panic(err)
	}
	fmt.Printf("%+v", p2)
}

Output:

{"Name":"Bob","Age":23}
{Name:Bob Age:23}

Notes:

The fields of the struct must be exported (start them with capital letter), else the json package (which uses reflection) will not be able to read/write them.

You can also specify tags for the struct fields to control/fine tune the json marshaling/unmarshaling process, for example to change the names in the JSON text:

type Person struct {
	Name string `json:"name"`
	Age  int    `json:"years"`
}

With this change the output of the above application is the following:

{"name":"Bob","years":23}
{Name:Bob Age:23}

The documentation of the json.Marshal() function details the possibilities provided by the tags.

And by implementing the json.Marshaler and json.Unmarshaler interfaces you can fully customize the marshaling / unmarshaling process.

Also if your struct is not pre-defined (e.g. you don't know the fields in advance), you can use a map[string]interface{}. See this answer for details and examples.

huangapple
  • 本文由 发表于 2015年5月15日 18:58:53
  • 转载请务必保留本文链接:https://go.coder-hub.com/30257817.html
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