Go语言中解码动态嵌套JSON结构：以DuckDuckGo API为例

package main

import (
    "encoding/json"
    "fmt"
    "log"
)

// Icon 结构体定义
type Icon struct {
    URL    string `json:"URL"`
    Height string `json:"Height"`
    Width  string `json:"Width"`
}

// Topic 结构体定义，包含递归字段
type Topic struct {
    Result   string  `json:"Result,omitempty"`
    Icon     Icon    `json:"Icon"`
    FirstURL string  `json:"FirstURL,omitempty"`
    Text     string  `json:"Text,omitempty"`

    // 递归字段：如果当前Topic是一个分组，它将包含一个子Topic列表
    Topics   []Topic `json:"Topics,omitempty"` 
    // 分组名称：如果当前Topic是一个分组，它将有一个名称
    Name     string  `json:"Name,omitempty"`
}

// RootObj 顶层结构体，包含RelatedTopics数组
type RootObj struct {
    RelatedTopics []Topic `json:"RelatedTopics"`
}

func main() {
    // 示例JSON数据 1: 仅包含独立主题
    json1 := `{
        "RelatedTopics" : [
            {
                "Result" : "<a href=\"http://duckduckgo.com/Criticism_of_Google\">Criticism of Google</a> - Criticism of Google includes possible misuse and manipulation of search results, its use of others' intellectual property, concerns that its compilation of data may violate people's privacy, cen...",
                "Icon" : { "URL" : "", "Height" : "", "Width" : "" },
                "FirstURL" : "http://duckduckgo.com/Criticism_of_Google",
                "Text" : "Criticism of Google - Criticism of Google includes possible misuse and manipulation of search results, its use of others' intellectual property, concerns that its compilation of data may violate people's privacy, cen..."
            },
            {
                "Result" : "<a href=\"http://duckduckgo.com/PRISM_(surveillance_program)\">PRISM</a> - PRISM is a clandestine mass electronic surveillance data mining program known to have been operated by the United States National Security Agency (NSA) since 2007.",
                "Icon" : { "URL" : "https://i.duckduckgo.com/i/e32c2703.jpg", "Height" : "16", "Width" : "16" },
                "FirstURL" : "http://duckduckgo.com/PRISM_(surveillance_program)",
                "Text" : "PRISM - PRISM is a clandestine mass electronic surveillance data mining program known to have been operated by the United States National Security Agency (NSA) since 2007."
            }
        ]
    }`

    // 示例JSON数据 2: 包含独立主题和主题分组
    json2 := `{
        "RelatedTopics" : [
            {
                "Result" : "<a href=\"http://duckduckgo.com/Doctor_Who\">Doctor Who</a> is the title of a long-running British science fiction series.",
                "Icon" : { "URL" : "https://i.duckduckgo.com/i/www.bbc.co.uk.ico", "Height" : 16, "Width" : 16 },
                "FirstURL" : "http://duckduckgo.com/Doctor_Who",
                "Text" : "Doctor Who is the title of a long-running British science fiction series."
            },
            {
                "Topics" : [
                    {
                        "Result" : "<a href=\"http://duckduckgo.com/Doctor_Who_(film)\">Doctor Who (film)</a>, the television movie starring Paul McGann, based on the television series",
                        "Icon" : { "URL" : "", "Height" : "", "Width" : "" },
                        "FirstURL" : "http://duckduckgo.com/Doctor_Who_(film)",
                        "Text" : "Doctor Who (film), the television movie starring Paul McGann, based on the television series"
                    },
                    {
                        "Result" : "<a href=\"http://duckduckgo.com/Dr._Who_(Dalek_films)\">Dr. Who (Dalek films)</a>, the human character played by Peter Cushing in two films based on the television series",
                        "Icon" : { "URL" : "https://i.duckduckgo.com/i/9f10647e.jpg", "Height" : "", "Width" : "" },
                        "FirstURL" : "http://duckduckgo.com/Dr._Who_(Dalek_films)",
                        "Text" : "Dr. Who (Dalek films), the human character played by Peter Cushing in two films based on the television series"
                    }
                ],
                "Name" : "In media and entertainment"
            },
            {
                "Topics" : [
                    {
                        "Result" : "<a href=\"http://duckduckgo.com/Neoregelia_'Dr._Who'\">Neoregelia 'Dr. Who'</a>, a hybrid cultivar of the genus Neoregelia in the Bromeliad family",
                        "Icon" : { "URL" : "", "Height" : "", "Width" : "" },
                        "FirstURL" : "http://duckduckgo.com/Neoregelia_'Dr._Who'",
                        "Text" : "Neoregelia 'Dr. Who', a hybrid cultivar of the genus Neoregelia in the Bromeliad family"
                    }
                ],
                "Name" : "In other uses"
            }
        ]
    }`

    fmt.Println("--- Decoding JSON Data 1 (Simple Topics) ---")
    decodeAndPrint(json1)

    fmt.Println("\n--- Decoding JSON Data 2 (Mixed Topics and Groups) ---")
    decodeAndPrint(json2)
}

func decodeAndPrint(jsonData string) {
    var root RootObj
    err := json.Unmarshal([]byte(jsonData), &root)
    if err != nil {
        log.Fatalf("Error unmarshaling JSON: %v", err)
    }

    for i, rt := range root.RelatedTopics {
        if rt.Name != "" && len(rt.Topics) > 0 {
            // 这是一个主题分组
            fmt.Printf("Related Topic Group %d (Name: %s):\n", i+1, rt.Name)
            for j, subTopic := range rt.Topics {
                fmt.Printf("  Sub-Topic %d: %s (URL: %s)\n", j+1, subTopic.Text, subTopic.FirstURL)
            }
        } else {
            // 这是一个独立主题
            fmt.Printf("Related Topic %d: %s (URL: %s)\n", i+1, rt.Text, rt.FirstURL)
        }
    }
}