解组多个XML项目

我的代码是:

package main

import (
    "encoding/xml"
    "fmt"
    "io/ioutil"
    "os"
)

// TideData stores a series of tide predictions
type TideData struct {
    Tides []Tide `xml:"data>item"`
}

// Tide stores a single tide prediction
type Tide struct {
    Date         string  `xml:"date"`
    Day          string  `xml:"day"`
    Time         string  `xml:"time"`
    PredictionFt float64 `xml:"predictions_in_ft"`
    PredictionCm float64 `xml:"predictions_in_cm"`
    HighLow      string  `xml:"highlow"`
}

func (t Tide) String() string {
    return t.Date + " " + t.Day + " " + t.Time + " " + t.HighLow
}

func main() {
    xmlFile, err := os.Open("9414275 Annual.xml")
    if err != nil {
        fmt.Println("Error opening file:", err)
        return
    }
    defer xmlFile.Close()

    b, _ := ioutil.ReadAll(xmlFile)

    var tides TideData
    xml.Unmarshal(b, &tides)

    fmt.Println(tides)
    for _, datum := range tides.Tides {
        fmt.Printf("\t%s\n", datum)
    }
}

运行时输出为空,这使我认为数据不是未编组的.输出是:

{[]}

James Henstr.. 5

你忽略了错误返回xml.Unmarshal.通过稍微修改您的程序,我们可以看到发生了什么:

xml: encoding "ISO-8859-1" declared but Decoder.CharsetReader is nil

而在文档中闲逛,我们发现,在默认情况下的包只支持XML的UTF-8编码:

    // CharsetReader, if non-nil, defines a function to generate
    // charset-conversion readers, converting from the provided
    // non-UTF-8 charset into UTF-8. If CharsetReader is nil or
    // returns an error, parsing stops with an error. One of the
    // the CharsetReader's result values must be non-nil.
    CharsetReader func(charset string, input io.Reader) (io.Reader, error)

因此,您似乎需要提供自己的字符集转换例程.您可以通过修改代码来注入它:

decoder := xml.NewDecoder(xmlFile)
decoder.CharsetReader = makeCharsetReader
err := decoder.Decode(&tides)

(请注意,我们现在正在从一个io.Reader而不是一个字节数组进行解码,因此ReadAll可以删除逻辑).该golang.org/x/text/encoding套餐的家庭可能会帮助您实施makeCharsetReader功能.像这样的东西可能会起作用:

import "golang.org/x/text/encoding/charmap"

func makeCharsetReader(charset string, input io.Reader) (io.Reader, error) {
    if charset == "ISO-8859-1" {
        // Windows-1252 is a superset of ISO-8859-1, so should do here
        return charmap.Windows1252.NewDecoder().Reader(input), nil
    }
    return nil, fmt.Errorf("Unknown charset: %s", charset)
}

然后,您应该能够解码XML.

你忽略了错误返回xml.Unmarshal.通过稍微修改您的程序,我们可以看到发生了什么:

xml: encoding "ISO-8859-1" declared but Decoder.CharsetReader is nil

而在文档中闲逛,我们发现,在默认情况下的包只支持XML的UTF-8编码:

    // CharsetReader, if non-nil, defines a function to generate
    // charset-conversion readers, converting from the provided
    // non-UTF-8 charset into UTF-8. If CharsetReader is nil or
    // returns an error, parsing stops with an error. One of the
    // the CharsetReader's result values must be non-nil.
    CharsetReader func(charset string, input io.Reader) (io.Reader, error)

因此,您似乎需要提供自己的字符集转换例程.您可以通过修改代码来注入它:

decoder := xml.NewDecoder(xmlFile)
decoder.CharsetReader = makeCharsetReader
err := decoder.Decode(&tides)

(请注意,我们现在正在从一个io.Reader而不是一个字节数组进行解码,因此ReadAll可以删除逻辑).该golang.org/x/text/encoding套餐的家庭可能会帮助您实施makeCharsetReader功能.像这样的东西可能会起作用:

import "golang.org/x/text/encoding/charmap"

func makeCharsetReader(charset string, input io.Reader) (io.Reader, error) {
    if charset == "ISO-8859-1" {
        // Windows-1252 is a superset of ISO-8859-1, so should do here
        return charmap.Windows1252.NewDecoder().Reader(input), nil
    }
    return nil, fmt.Errorf("Unknown charset: %s", charset)
}

然后,您应该能够解码XML.