Go语言处理JSON之——利用Unmarshal解析json字符串

简单的解析例子：
首先还是从官方文档中的例子：

package main

import (
	"fmt"
	"encoding/json"
)

type Animal struct {
    Name  string
    Order string
}

func main() {
	var jsonBlob = []byte(`[
		{"Name": "Platypus", "Order": "Monotremata"},
		{"Name": "Quoll",    "Order": "Dasyuromorphia"}
	]`)

	var animals []Animal
	
	err := json.Unmarshal(jsonBlob, &animals)
	if err != nil {
	    fmt.Println("error:", err)
	}
	fmt.Printf("%+v", animals)
}

输出：

[{Name:Platypus Order:Monotremata} {Name:Quoll Order:Dasyuromorphia}]

简单进行修改，修改为：

package main

import (
	"fmt"
	"encoding/json"
)

type Animal struct {
    Name  string
    Order string
}

func main() {
	var jsonBlob = []byte(`{"Name": "Platypus", "Order": "Monotremata"}`)
	var animals Animal
	err := json.Unmarshal(jsonBlob, &animals)
	if err != nil {
	    fmt.Println("error:", err)
	}
	fmt.Printf("%+v", animals)
}

输出：

{Name:Platypus Order:Monotremata}

还是之前的例子：
解析这样的一个json字符串：

{
    "first fruit":
    {
        "describe":"an apple",
        "icon":"appleIcon",
        "name":"apple"
    },
    "second fruit":
    {
        "describe":"an orange",
        "icon":"orangeIcon",
        "name":"orange"
    },
    "three fruit array":
    [
        "eat 0",
        "eat 1",
        "eat 2",
        "eat 3",
        "eat 4"
    ]
}

go代码：

package main

import (
	"fmt"
	"encoding/json"
)

type Fruit struct {
	Describe string `json:"describe"`
	Icon     string `json:"icon"`
	Name     string `json:"name"`
}

type FruitGroup struct {
	FirstFruit  *Fruit `json:"first fruit"`  //指针，指向引用对象；如果不用指针，只是值复制
	SecondFruit *Fruit `json:"second fruit"` //指针，指向引用对象；如果不用指针，只是值复制
	THreeFruitArray []string `json:"three fruit array"`
}

func main() {
	var jsonBlob = []byte(`{
    "first fruit": {
        "describe": "an apple",
        "icon": "appleIcon",
        "name": "apple"
    },
    "second fruit": {
        "describe": "an orange",
        "icon": "appleIcon",
        "name": "orange"
    },
    "three fruit array": [
        "eat 0",
        "eat 1",
        "eat 2",
        "eat 3"
    ]}`)

	var fruitGroup FruitGroup
	
	err := json.Unmarshal(jsonBlob, &fruitGroup)
	if err != nil {
	    fmt.Println("error:", err)
	}
	fmt.Printf("%+v\n", fruitGroup)
	fmt.Printf("%+v\n", fruitGroup.FirstFruit)
	fmt.Printf("%+v\n", fruitGroup.SecondFruit)
}

运行结果：

{FirstFruit:0xc00006c5a0 SecondFruit:0xc00006c5d0 THreeFruitArray:[eat 0 eat 1 eat 2 eat 3]}
&{Describe:an apple Icon:appleIcon Name:apple}
&{Describe:an orange Icon:appleIcon Name:orange}