Golang将JSON转换为切片的映射，映射本身包含切片（无需类型）

huangapple
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英文:

Golang JSON to Slice of Maps of Maps themselves Containing Slices (without Types)

问题

我有一个名为config.json的文件，格式如下：

  1. {
  2.     "recordType1": [
  3.         "field1", "field2", "field3", "field4", "field5"
  4.     ],
  5.     "recordType2": [
  6.         "field1", "field2", "field3", "field4", "field5", "field6", "field7"
  7.     ]
  8. }

如果可能的话，我想将其转换为一个切片（slice）的映射（map），其中每个映射本身是一个单独的键（key），而值（value）是一个切片。

我可以手动完成这个操作，像这样：

  1. package main
  3. import "fmt"
  5. func main() {
  6.     m := make(map[string][]string, 0)
  7.     m2 := make(map[string][]string, 0)
  8.     sliceOfMaps := make([]map[string][]string, 0)
  10.     m["recordType1"] = []string{"field1", "field2", "field3"}
  11.     m2["recordType2"] = []string{"field1", "field2", "field3", "field4", "field5"}
  12.     sliceOfMaps = append(sliceOfMaps, m, m2)
  14.     fmt.Println(m)
  15.     fmt.Println(m2)
  16.     fmt.Println(sliceOfMaps)
  17. }

相反，我想对config.json的内容调用json.Unmarshal，将该JSON解析为相同的结构。

我尝试过以下方法：

  1. package main
  3. import (
  4.     "fmt"
  5.     "encoding/json"
  6.     "io/ioutil"
  7.     "log"
  8. )
  10. func main() {
  11.     file, err := ioutil.ReadFile("config/config.json")
  12.     if err != nil {
  13.         log.Fatal("读取文件错误：", err)
  14.     }
  16.     var sliceOfMaps []map[string][]string
  17.     sliceOfMaps = make([]map[string][]string, 0)
  19.     err = json.Unmarshal(file, &sliceOfMaps)
  20.     if err != nil {
  21.         log.Fatal("解析JSON错误", err)
  22.     }
  24.     fmt.Println(sliceOfMaps)
  25. }

这会产生错误：

  1. 解析JSON错误：json: cannot unmarshal object into Go value of type []map[string][]string

非常感谢您的帮助，欢迎提出澄清问题。谢谢。

英文:

I have a config.json with the following format:

  1. {
  2. 	"recordType1": [
  3. 		"field1", "field2", "field3", "field4", "field5"
  4. 	],
  5. 	"recordType2": [
  6. 		"field1", "field2", "field3", "field4", "field5", "field6", "field7"
  7. 	]
  8. }

If possible, I'd like to convert this to a slice of maps, where each map is itself is a single 'key', and the 'value' is a slice.

I can accomplish this manually like:

  1. package main
  3. import ("fmt")
  5. func main() {
  6.         m := make(map[string][]string, 0)
  7.         m2 := make(map[string][]string, 0)
  8.         sliceOfMaps := make([]map[string][]string, 0)
  10.         m["recordType1"] = []string{"field1", "field2", "field3"}
  11.         m2["recordType2"] = []string{"field1", "field2", "field3", "field4", "field5"}
  12.         sliceOfMaps = append(sliceOfMaps, m, m2)
  14.         fmt.Println(m)
  15.         fmt.Println(m2)
  16.         fmt.Println(sliceOfMaps)
  17. }

Instead, I'd like to invoke json.Unmarshal on the contents of config.json to parse that json into the very same structure.

What I've tried so far:

  1. package main
  3. import (
  4.     "fmt"
  5.     "encoding/json"
  6.     "io/ioutil"
  7.     "log"
  8. )
  11.     func main() {
  12.         file, err := ioutil.ReadFile("config/config.json")
  13.         if err != nil {
  14.                 log.Fatal("Err Reading File:", err)
  15.         }
  16.     
  17.         var sliceOfMaps []map[string][]string
  18.         sliceOfMaps = make([]map[string][]string, 0)
  19.     
  20.         err = json.Unmarshal(file, &sliceOfMaps)
  21.         if err != nil {
  22.                 log.Fatal("Err Parsing JSON", err)
  23.         }
  24.     
  25.         fmt.Println(sliceOfMaps)
  26.     }

This produces error:

  1. Err Parsing JSONjson: cannot unmarshal object into Go value of type []map[string][]string

Any assistance is greatly appreciated, clarifying questions welcome. Thanks.

答案1

得分: 4

你的JSON输入和"manual"示例都使用了切片的映射，而不是映射的切片。将目标类型更改为map[string][]string，然后你就可以运行了：

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"encoding/json"
  6. )
  8. var file = []byte(`{
  9.     "recordType1": [
  10.         "field1", "field2", "field3", "field4", "field5"
  11.     ],
  12.     "recordType2": [
  13.         "field1", "field2", "field3", "field4", "field5", "field6", "field7"
  14.     ]
  15. }`)
  17. func main() {
  18. 	output := map[string][]string{}
  19. 	if err := json.Unmarshal(file, &output); err != nil {
  20. 		panic(err)
  21. 	}
  22. 	fmt.Println(output)
  23. }

产生以下输出：

  1. map[recordType1:[field1 field2 field3 field4 field5] recordType2:[field1 field2 field3 field4 field5 field6 field7]]

Playground链接。

英文:

Both your JSON input, and your "manual" example are using maps of slices, not slices of maps. Change your target type to map[string][]string and you should be good to go:

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"encoding/json"
  6. )
  8. var file = []byte(`{
  9.     "recordType1": [
  10.         "field1", "field2", "field3", "field4", "field5"
  11.     ],
  12.     "recordType2": [
  13.         "field1", "field2", "field3", "field4", "field5", "field6", "field7"
  14.     ]
  15. }`)
  17. func main() {
  18. 	output := map[string][]string{}
  19. 	if err := json.Unmarshal(file, &output); err != nil {
  20. 		panic(err)
  21. 	}
  22. 	fmt.Println(output)
  23. }

Produces the following output:

  1. map[recordType1:[field1 field2 field3 field4 field5] recordType2:[field1 field2 field3 field4 field5 field6 field7]]

Playground link.

huangapple
  • 本文由 发表于 2017年8月17日 01:04:48
  • 转载请务必保留本文链接：https://go.coder-hub.com/45719297.html
  • go
  • hashmap
  • json
  • slice
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