Question

所以，说我在JSON中有一些文章。

{"articles": [{"title": "This is an awesome post.", "content": "How amazing is this article actually?"}, {"title": "Asking a question on StackOerflow", "content": "It's very easy."}]}

所以我想按顺序阅读文章，即这是一篇很棒的文章，然后在StackOverflow上提问。然后我必须按顺序编辑或写入它们，所以当我有一个新帖子时，它将是：

{"articles": [{"title": "New Post", "content": "Content"},{"title": "This is an awesome post.", "content": "How amazing is this article actually?"}, {"title": "Asking a question on StackOerflow", "content": "It's very easy."}]}

或更新：

{"articles": [{"title": "New Post", "content": "Content of new post"},{"title": "This is an awesome post.", "content": "How amazing is this article actually?"}, {"title": "Asking a question on StackOerflow", "content": "It's very easy."}]}

我打算用他们的头衔操纵文章，但我还没有能够在Go（写作和更新）中获得这样的操作。你能救我一下吗？

我已经能够阅读2个接口，但我不知道如何写，更新。

type Articles struct {
    Article []Article
}

type Article struct {
    Title   string
    Content string
}

Answer 1

这是另一种方法：http://play.golang.org/p/K-eYSrn1tx

我会在这里复制代码以便于查看：

package main

import (
    "encoding/json"
    "fmt"
)

type JsonDoc struct {
    Articles []Article
}

type Article struct {
    Title   string
    Content string
}

func main() {
    s := `{"articles": [
    {"title": "This is an awesome post.", 
     "content": "How amazing is this article actually?"}, 
    {"title": "Asking a question on StackOverflow",
     "content": "It's very easy."}]}`

    doc := JsonDoc{}
    // Toy example.  In a real application, we should not ignore
    // the possibility of an error here.
    json.Unmarshal([]byte(s), &doc)

    fmt.Printf("Before: %#v\n", doc)

    // Note: adding to the front of a slice is a bit expensive.
    // Consider adding to the back, or use a data representation
    // that's more appropriate.
    frontArticle := Article{Title: "Another article",
        Content: "Here's its content."}
    doc.Articles = append([]Article{frontArticle},
        doc.Articles...)

    fmt.Printf("After: %#v\n", doc)

    // Toy example: in a real application, we should not ignore
    // the possibility of an error here.
    marshalled, _ := json.Marshal(&doc)
    fmt.Printf("%s\n", marshalled)
}

您会注意到，关键名称的编组输出与输入略有不同。输入使用了小写键，但我们的输出正在生成大写键！你需要告诉JSON编码器更多关于外部表示的信息，这样它才能在编组时做正确的事情。这是使用struct field标签的一种方法：http://play.golang.org/p/HHeMQUcCDV

Answer 2

好的，我已经解决了它：

    s := `{"articles": [{"title": "This is an awesome post.", "content": "How amazing is this article actually?"}, {"title": "Asking a question on StackOverflow", "content": "It's very easy."}]}`
    items := &Articles{}
    json.Unmarshal([]byte(s), items)
    theLength := len(items.Article) + 1
    newArray := make([]Article, theLength)
    newArray[0] = Article{"My New Title", "My New Content"}
    for i := 1; i < theLength; i++ {
        newArray[i] = items.Article[i-1]
    }
    newItems := &Articles{}
    newItems.Article = newArray
    //now newItems is the new interface

在Go（Golang）写作和阅读json

2 个答案: