英文:
Parsing xml with Go, having multiple items
问题
我只能翻译代码部分，以下是翻译好的代码：
package main
import (
"fmt"
"io/ioutil"
"log"
"net/http"
"encoding/xml"
)
type RSS struct {
XMLName xml.Name `xml:"rss"`
items Items `xml:"channel"`
}
type Items struct {
XMLName xml.Name `xml:"channel"`
ItemList []Item `xml:"item"`
}
type Item struct {
Title string `xml:"title"`
Link string `xml:"link"`
Description string `xml:"description"`
}
func main() {
res, err := http.Get("http://news.google.com/news?hl=en&gl=us&q=samsung&um=1&ie=UTF-8&output=rss")
if err != nil {
log.Fatal(err)
}
asText, err := ioutil.ReadAll(res.Body)
if err != nil {
log.Fatal(err)
}
var i RSS
err = xml.Unmarshal([]byte(asText), &i)
if err != nil {
log.Fatal(err)
}
fmt.Printf("%#v", i)
for c, item := range i.items.ItemList {
fmt.Printf("\t%d: %s\n", c, item.Title)
}
res.Body.Close()
}
输出结果如下：
main.RSS{XMLName:xml.Name{Space:"", Local:"rss"}, items:main.Items{XMLName:xml.Name{Space:"", Local:""}, ItemList:[]main.Item(nil)}}
英文:
I just can't get this simple thing to work. I'm just trying to parse a simple RSS XML and put all the items in an array of structs.
this is my code:
package main
import (
"fmt"
"io/ioutil"
"log"
"net/http"
"encoding/xml"
)
type RSS struct {
XMLName xml.Name `xml:"rss"`
items Items `xml:"channel"`
}
type Items struct {
XMLName xml.Name `xml:"channel"`
ItemList []Item `xml:"item"`
}
type Item struct {
title string `xml:"title"`
link string
description string
}
func main() {
res, err := http.Get("http://news.google.com/news?hl=en&gl=us&q=samsung&um=1&ie=UTF-8&output=rss")
if err != nil {
log.Fatal(err)
}
asText, err := ioutil.ReadAll(res.Body)
if err != nil {
log.Fatal(err)
}
var i RSS
err = xml.Unmarshal([]byte(asText), &i)
if err != nil {
log.Fatal(err)
}
// fmt.Printf("\ttxt2: %s\n", asText)
fmt.Printf("%#v", i)
for c, item := range i.items.ItemList {
fmt.Printf("\t%d: %s\n", c, item.title)
}
res.Body.Close()
}
this is the output of dumping i:
main.RSS{XMLName:xml.Name{Space:"", Local:"rss"}, items:main.Items{XMLName:xml.Name{Space:"", Local:""}, ItemList:[]main.Item(nil)}}
答案1
得分: 9
从Unmarshal的文档中：
因为Unmarshal使用reflect包，它只能赋值给导出的（大写）字段。Unmarshal使用区分大小写的比较将XML元素名称与标签值和结构字段名称进行匹配。
所以你需要将结构字段名称改为大写。不幸的是，这样它们就不再与XML元素名称匹配，所以你需要重复它们的小写版本。
这是一个使用你的RSS feed的前两个项目的工作示例：https://go.dev/play/p/IJpEC2qpUWo
英文:
From the docs of Unmarshal:
> Because Unmarshal uses the reflect package, it can only assign to exported (upper case) fields. Unmarshal uses a case-sensitive comparison to match XML element names to tag values and struct field names.
So you need to upper-case your struct field names. Unfortunately, then they don't match the XML element names anymore, so you'll have to repeat their lower-case versions.
Here's a working example with the first two items of your RSS feed: https://go.dev/play/p/IJpEC2qpUWo
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