/
json.go
88 lines (74 loc) · 2.38 KB
/
json.go
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// Copyright (c) 2016 OpenM++
// This code is licensed under the MIT license (see LICENSE.txt for details)
package helper
import (
"bytes"
"encoding/json"
"errors"
"io"
"os"
)
// FromJsonFile reads read from json file and convert to destination pointer.
func FromJsonFile(jsonPath string, dst interface{}) (bool, error) {
// open file and convert to utf-8
f, err := os.Open(jsonPath)
if err != nil {
if os.IsNotExist(err) {
return false, nil // return: json file not exist
}
return false, errors.New("json file open error: " + err.Error())
}
defer f.Close()
// make utf-8 converter:
// assume utf-8 as default encoding on any OS because json file must be unicode and cannot be "windows code page"
rd, err := Utf8Reader(f, "utf-8")
if err != nil {
return false, errors.New("json file read error: " + err.Error())
}
// decode json
err = json.NewDecoder(rd).Decode(dst)
if err != nil {
if err == io.EOF {
return false, nil // return "not exist" if json file empty
}
return false, errors.New("json decode error: " + err.Error())
}
return true, nil
}
// FromJson restore from json string bytes and convert to destination pointer.
func FromJson(srcJson []byte, dst interface{}) (bool, error) {
err := json.NewDecoder(bytes.NewReader(srcJson)).Decode(dst)
if err != nil {
if err == io.EOF {
return false, nil // return "not exist" if json empty
}
return false, errors.New("json decode error: " + err.Error())
}
return true, nil
}
// ToJsonFile convert source to json and write into jsonPath file.
func ToJsonFile(jsonPath string, src interface{}) error {
f, err := os.OpenFile(jsonPath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
if err != nil {
return errors.New("json file create error: " + err.Error())
}
defer f.Close()
err = json.NewEncoder(f).Encode(src)
if err != nil {
return errors.New("json encode error: " + err.Error())
}
return nil
}
// ToJsonIndent return source conveted to json indeneted string.
func ToJsonIndent(src interface{}) (string, error) {
srcJson, err := json.Marshal(src)
if err != nil {
return "", errors.New("json marshal error: " + err.Error())
}
var srcIndent bytes.Buffer
err = json.Indent(&srcIndent, srcJson, "", " ")
if err != nil {
return "", errors.New("json indent error: " + err.Error())
}
return srcIndent.String(), nil
}