gf/encoding/gcharset/gcharset.go

112 lines
3.0 KiB
Go

// Copyright 2018-2019 gf Author(https://github.com/gogf/gf). All Rights Reserved.
//
// This Source Code Form is subject to the terms of the MIT License.
// If a copy of the MIT was not distributed with this file,
// You can obtain one at https://github.com/gogf/gf.
// Package charset implements character-set conversion functionality.
//
// Supported Character Set:
//
// Chinese : GBK/GB18030/GB2312/Big5
//
// Japanese: EUCJP/ISO2022JP/ShiftJIS
//
// Korean : EUCKR
//
// Unicode : UTF-8/UTF-16/UTF-16BE/UTF-16LE
//
// Other : macintosh/IBM*/Windows*/ISO-*
package gcharset
import (
"bytes"
"errors"
"fmt"
"io/ioutil"
"golang.org/x/text/encoding"
"golang.org/x/text/encoding/ianaindex"
"golang.org/x/text/transform"
)
var (
// Alias for charsets.
charsetAlias = map[string]string{
"HZGB2312": "HZ-GB-2312",
"hzgb2312": "HZ-GB-2312",
"GB2312": "HZ-GB-2312",
"gb2312": "HZ-GB-2312",
}
)
// Supported returns whether charset <charset> is supported.
func Supported(charset string) bool {
return getEncoding(charset) != nil
}
// Convert converts <src> charset encoding from <srcCharset> to <dstCharset>,
// and returns the converted string.
// It returns <src> as <dst> if it fails converting.
func Convert(dstCharset string, srcCharset string, src string) (dst string, err error) {
if dstCharset == srcCharset {
return src, nil
}
dst = src
// Converting <src> to UTF-8.
if srcCharset != "UTF-8" {
if e := getEncoding(srcCharset); e != nil {
tmp, err := ioutil.ReadAll(
transform.NewReader(bytes.NewReader([]byte(src)), e.NewDecoder()),
)
if err != nil {
return "", fmt.Errorf("%s to utf8 failed. %v", srcCharset, err)
}
src = string(tmp)
} else {
return dst, errors.New(fmt.Sprintf("unsupport srcCharset: %s", srcCharset))
}
}
// Do the converting from UTF-8 to <dstCharset>.
if dstCharset != "UTF-8" {
if e := getEncoding(dstCharset); e != nil {
tmp, err := ioutil.ReadAll(
transform.NewReader(bytes.NewReader([]byte(src)), e.NewEncoder()),
)
if err != nil {
return "", fmt.Errorf("utf to %s failed. %v", dstCharset, err)
}
dst = string(tmp)
} else {
return dst, errors.New(fmt.Sprintf("unsupport dstCharset: %s", dstCharset))
}
} else {
dst = src
}
return dst, nil
}
// ToUTF8 converts <src> charset encoding from <srcCharset> to UTF-8 ,
// and returns the converted string.
func ToUTF8(srcCharset string, src string) (dst string, err error) {
return Convert("UTF-8", srcCharset, src)
}
// UTF8To converts <src> charset encoding from UTF-8 to <dstCharset>,
// and returns the converted string.
func UTF8To(dstCharset string, src string) (dst string, err error) {
return Convert(dstCharset, "UTF-8", src)
}
// getEncoding returns the encoding.Encoding interface object for <charset>.
// It returns nil if <charset> is not supported.
func getEncoding(charset string) encoding.Encoding {
if c, ok := charsetAlias[charset]; ok {
charset = c
}
if e, err := ianaindex.MIB.Encoding(charset); err == nil && e != nil {
return e
}
return nil
}