将JSON数组返回到Struct Golang

Question

My main objective is to pass a JSON object back to a client. However, I keep getting nil or empty values in my struct. How do I get the expected and desired JSON array response? Below is my code snippet.

package main

import (
    "net/http"
    "fmt"
    "encoding/json"
)

type News struct {
    NewsID      int     `json:"newsId"`
    PlayerID    int     `json:"playerId"`
    TeamID      int     `json:"teamId"`
    Team        string  `json:"team"`
    Title       string  `json:"title"`
    Content     string  `json:"content"`
    Url         string  `json:"url"`
    Source      string  `json:"source"`
    TermsOfUse  string  `json:"terms"`
    Updated     string  `json:"updated"`
}

func GetBoxScore (w http.ResponseWriter, r *http.Request) {
    news := News{}
    req, _ := http.NewRequest("GET","https://api.fantasydata.net/v3/nhlpb/scores/JSON/News", nil)
    req.Header.Set("Ocp-Apim-Subscription-Key", "API KEY")
    req.Host = "api.fantasydata.net"
    client := &http.Client{}
    res, err := client.Do(req)
    defer res.Body.Close()

    if err != nil {
        fmt.Printf("The HTTP request failed with error %s\n", err)
    }
    err = json.NewDecoder(r.Body).Decode(&news)
    newsJson, err := json.Marshal(news)
    if err != nil {
        panic(err)
    }
    w.Header().Set("Content-Type", "application/json")
    w.WriteHeader(http.StatusAccepted)
    w.Write(newsJson)
}

Currently, the response is my empty News struct, all with nil values. The response I want and was expecting is below:

  [
        {
            "NewsID": 8919,
            "PlayerID": 30003647,
            "TeamID": 28,
            "Team": "VAN",
            "Title": "Rumors have Elias Pettersson back this week",
            "Content": "The rumor mill has Elias Pettersson (concussion) returning this week.",
            "Url": "http://www.rotoworld.com/player/nhl/5819/elias-pettersson",
            "Source": "NBCSports.com",
            "TermsOfUse": "NBCSports.com feeds in the RSS format are provided free of charge for use by individuals for personal, non-commercial uses. More details here: http://fantasydata.com/resources/rotoworld-rss-feed.aspx",
            "Updated": "2018-10-21T11:54:00"
        },
        {
            "NewsID": 8918,
            "PlayerID": 30000294,
            "TeamID": 10,
            "Team": "NJ",
            "Title": "Cory Schneider gives up three in AHL loss",
            "Content": "Cory Schneider (hip) played for the first time this season, albeit in the AHL.",
            "Url": "http://www.rotoworld.com/player/nhl/2139/cory-schneider",
            "Source": "NBCSports.com",
            "TermsOfUse": "NBCSports.com feeds in the RSS format are provided free of charge for use by individuals for personal, non-commercial uses. More details here: http://fantasydata.com/resources/rotoworld-rss-feed.aspx",
            "Updated": "2018-10-21T08:01:00"
        }, 
]

Answer 1

There are two things I would mention here. First, are you getting the response you are expecting? You might want to check that.

The second, the json you provided is an array of news, and not a single news. You might want to change the type of news to an array rather than a single news.

type NewsItem struct {
    NewsID      int     `json:"newsId"`
    PlayerID    int     `json:"playerId"`
    TeamID      int     `json:"teamId"`
    Team        string  `json:"team"`
    Title       string  `json:"title"`
    Content     string  `json:"content"`
    Url         string  `json:"url"`
    Source      string  `json:"source"`
    TermsOfUse  string  `json:"terms"`
    Updated     string  `json:"updated"`
}

type News []NewsItem

Answer 2

In the following line

err = json.NewDecoder(r.Body).Decode(&news)

you are passing news struct where as the json is actually an array. Hence you need to create a slice of news struct and then pass that.

newsList := make([]News,0)
err = json.NewDecoder(r.Body).Decode(&newsList)