如何在Go中将所有编码都转换为UTF 8？

我正在通过 IMAP 下载消息。接下来，我将解析消息添加到 MongoDB 中，但我遇到了一个问题，因为 MongoDB 只支持 UTF 8， 我想把所有编码都转换成 UTF 8的话该怎么做？

我知道可以转换为二进制，但我必须有正常的文本，因为我必须在数据库中搜索短语。除非——我可以搜索二进制的正常文本吗？

I'm using the go-charset project to do this: https://code.google.com/p/go-charset/

It's pretty straightforward, you create a reader from a charset and it translates to utf-8 automatically. example from the library:

r, err := charset.NewReader(strings.NewReader("\xa35 for Pepp\xe9"), "latin1")
if err != nil {
    log.Fatal(err)
}
result, err := ioutil.ReadAll(r)
if err != nil {
    log.Fatal(err)
}
fmt.Printf("%s
", result)  //outputs £5 for Peppé

Now, in my case I know the charset because it comes from web pages and I read the headers/meta tags. If you need to detect the charset automatically by heuristics, you'll need another library for that, such as this one: https://github.com/saintfish/chardet

I haven't used it but it also looks pretty simple to use:

detector := chardet.NewTextDetector()
result, err := detector.DetectBest(some_text)
if err == nil {
    fmt.Printf(
        "Detected charset is %s, language is %s",
        result.Charset,
        result.Language)
}

I've found a better package, which uses iconv. Usage is trivial, it is described in the documentation. For example:

output,_ := iconv.ConvertString("Hello World!", "windows-1252", "utf-8")

Link to the package: https://github.com/djimenez/iconv-go

charset.NewReader in package golang.org/x/net/html/charset can't deal with encoding gb2312. charset.NewReaderLabel can deal with it.

import  (
    "io/ioutil"
    "golang.org/x/net/html/charset"
)

func convrtToUTF8(str string, origEncoding string) string {
    strBytes := []byte(str)
    byteReader := bytes.NewReader(strBytes)
    reader, _ := charset.NewReaderLabel(origEncoding, byteReader)
    strBytes, _ = ioutil.ReadAll(reader)
    return string(strBytes)
}