Reputation: 875
I have a config.json
with the following format:
{
"recordType1": [
"field1", "field2", "field3", "field4", "field5"
],
"recordType2": [
"field1", "field2", "field3", "field4", "field5", "field6", "field7"
]
}
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:
package main
import ("fmt")
func main() {
m := make(map[string][]string, 0)
m2 := make(map[string][]string, 0)
sliceOfMaps := make([]map[string][]string, 0)
m["recordType1"] = []string{"field1", "field2", "field3"}
m2["recordType2"] = []string{"field1", "field2", "field3", "field4", "field5"}
sliceOfMaps = append(sliceOfMaps, m, m2)
fmt.Println(m)
fmt.Println(m2)
fmt.Println(sliceOfMaps)
}
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:
package main
import (
"fmt"
"encoding/json"
"io/ioutil"
"log"
)
func main() {
file, err := ioutil.ReadFile("config/config.json")
if err != nil {
log.Fatal("Err Reading File:", err)
}
var sliceOfMaps []map[string][]string
sliceOfMaps = make([]map[string][]string, 0)
err = json.Unmarshal(file, &sliceOfMaps)
if err != nil {
log.Fatal("Err Parsing JSON", err)
}
fmt.Println(sliceOfMaps)
}
This produces error:
Err Parsing JSONjson: cannot unmarshal object into Go value of type []map[string][]string
Any assistance is greatly appreciated, clarifying questions welcome. Thanks.
Upvotes: 2
Views: 930
Reputation: 79774
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:
package main
import (
"fmt"
"encoding/json"
)
var file = []byte(`{
"recordType1": [
"field1", "field2", "field3", "field4", "field5"
],
"recordType2": [
"field1", "field2", "field3", "field4", "field5", "field6", "field7"
]
}`)
func main() {
output := map[string][]string{}
if err := json.Unmarshal(file, &output); err != nil {
panic(err)
}
fmt.Println(output)
}
Produces the following output:
map[recordType1:[field1 field2 field3 field4 field5] recordType2:[field1 field2 field3 field4 field5 field6 field7]]
Upvotes: 4