使用simplejson实现JSON

Question

Trying to use the JSON lib from "github.com/bitly/go-simplejson"

url = "http://api.stackoverflow.com/1.1/tags?pagesize=100&page=1"
res, err := http.Get(url)
body, err := ioutil.ReadAll(res.Body)
fmt.Printf("%s
", string(body)) //WORKS
js, err := simplejson.NewJson(body)

total,_ := js.Get("total").String()    
fmt.Printf("Total:%s"+total )

But it seems it doenst work !? Trying to access the total and tag fields

Answer 1

You have a few mistakes:

1. If you'll check the JSON response you'll notice that total field is not string, that's why you should use MustInt() method, not String(), when you are accessing the field.
2. Printf() method invocation was totally wrong. You should pass a "template", and then pass arguments appropriate to the number of "placeholders".

By the way, I strongly recomend you to check err != nil everywhere, that'll help you a lot.

Here is the working example:

package main

import (
    "fmt"
    "github.com/bitly/go-simplejson"
    "io/ioutil"
    "log"
    "net/http"
)

func main() {
    url := "http://api.stackoverflow.com/1.1/tags?pagesize=100&page=1"
    res, err := http.Get(url)
    if err != nil {
        log.Fatalln(err)
    }

    body, err := ioutil.ReadAll(res.Body)
    if err != nil {
        log.Fatalln(err)
    }

    // fmt.Printf("%s
", string(body))

    js, err := simplejson.NewJson(body)
    if err != nil {
        log.Fatalln(err)
    }

    total := js.Get("total").MustInt()
    if err != nil {
        log.Fatalln(err)
    }

    fmt.Printf("Total:%s", total)
}