代码示例：

package main

import (
    "encoding/json"
    "github.com/gorilla/mux"
    "net/http"
)

// 定义Product的结构体
type Product struct {
    Name  string  `json:"name"`
    Price float64 `json:"price"`
    Num   int32
    Desc  string
}

// 定义Shop的结构体
type Shop struct {
    Name    string `json:"name"`
    Address string `json:"address"`
}

// 初始化Product和Shop的切片
var productlist []Product
var shoplist []Shop

// 获取Product列表
func getProductListHandler(w http.ResponseWriter, r *http.Request) {
    // Header设置Content-Type为json格式，输出json格式的结果，看起来更方便
    w.Header().Set("Content-Type", "application/json")
    w.WriteHeader(http.StatusOK)
    json.NewEncoder(w).Encode(productlist)
}

// 获取Shop列表
func getShopListHandler(w http.ResponseWriter, r *http.Request) {
    // Header设置Content-Type为json格式，输出json格式的结果，看起来更方便
    w.Header().Set("Content-Type", "application/json")
    w.WriteHeader(http.StatusOK)
    json.NewEncoder(w).Encode(shoplist)
}

func main() {
    // 初始化ProductList的数据
    productlist = append(productlist, Product{Name: "地球仪", Price: 10, Num: 102, Desc: "世界地球仪，360度旋转"})
    productlist = append(productlist, Product{Name: "鱼缸", Price: 28.8, Num: 2, Desc: "长50cm,宽28cm,高60cm"})
    // 初始化ShopList的数据
    shoplist = append(shoplist, Shop{Name: "苹果太古里店", Address: "成都太古里"})
    shoplist = append(shoplist, Shop{Name: "优衣库三里屯店", Address: "北京三里屯"})

    // 初始化一个新的路由
    r := mux.NewRouter()

    // Product的子路由
    p := r.PathPrefix("/products").Subrouter()
    p.HandleFunc("/list", getProductListHandler).Methods("GET")
    // Shop的子路由
    s := r.PathPrefix("/shop").Subrouter()
    s.HandleFunc("/list", getShopListHandler).Methods("GET")
    // 监听8001端口
    http.ListenAndServe(":8001", r)
}

运行程序，通过postman或其它http请求工具发送请求，下面是测试的结果。

1、GET请求http://localhost:8001/products/list，结果：

[
    {
        "name": "地球仪",
        "price": 10,
        "Num": 102,
        "Desc": "世界地球仪，360度旋转"
    },
    {
        "name": "鱼缸",
        "price": 28.8,
        "Num": 2,
        "Desc": "长50cm,宽28cm,高60cm"
    }
]

2、GET请求http://localhost:8001/shop/list，结果：

[
    {
        "name": "苹果太古里店",
        "address": "成都太古里"
    },
    {
        "name": "优衣库三里屯店",
        "address": "北京三里屯"
    }
]

以上就是mux子路由的基本使用，git地址：https://gitee.com/sunzf/test-go/blob/master/src/mux/Products.go