Go语言JSON包使用

目录

序列化与反序列化

1、序列化

1）结构体数据转JSON，属性必须是公有的大写开头
使用Person结构体描述用户信息并转JSON

package main

import (
	"encoding/json"
	"fmt"
)

type Person struct {
    
	Name  string
	Age   int
	Rmb   float64
	Sex   bool
	Hobby []string
}

func main() {
    
	person := Person{
    "于谦", 50, 123.45, true, []string{
    "抽烟", "喝酒", "烫头"}}
	bytes, e := json.Marshal(person)
	if e != nil {
    
		fmt.Println("序列化失败,err=", e)
		return
	}
	fmt.Println(string(bytes))
}

2）Map数据转JSON
使用map[string]interface{}描述用户信息并转JSON

package main

import (
	"encoding/json"
	"fmt"
)

func main() {
    
	dataMap := make(map[string]interface{
    })
	dataMap["name"] = "于谦"
	dataMap["age"] = 50
	dataMap["rmb"] = 123.45
	dataMap["sex"] = true
	dataMap["hobby"] = []string{
    "抽烟", "喝酒", "烫头"}

	bytes, e := json.Marshal(dataMap)
	if e != nil {
    
		fmt.Println("序列化失败,err=", e)
		return
	}
	fmt.Println(string(bytes))
}

3）map切片数据转JSON
使用map切片描述多个用户信息并转JSON

package main

import (
	"encoding/json"
	"fmt"
)

func main() {
    
	dataMap1 := make(map[string]interface{
    })
	dataMap1["name"] = "王钢蛋"
	dataMap1["hobby"] = []string{
    "抽中华", "喝牛栏山", "烫花卷头"}

	dataMap2 := make(map[string]interface{
    })
	dataMap2["name"] = "王铁蛋"
	dataMap2["hobby"] = []string{
    "抽玉溪", "喝五粮液", "烫杀马特"}

	dataMap3 := make(map[string]interface{
    })
	dataMap3["name"] = "王铜蛋"
	dataMap3["hobby"] = []string{
    "抽小熊猫", "喝剑南春", "烫鸡冠头"}

	dataSlice := make([]map[string]interface{
    }, 0)
	dataSlice = append(dataSlice, dataMap1, dataMap2, dataMap3)

	bytes, e := json.Marshal(dataSlice)
	if e != nil {
    
		fmt.Println("序列化失败,err=", e)
		return
	}
	fmt.Println(string(bytes))
}

2、反序列化

1）JSON转结构体数据

package main

import (
	"encoding/json"
	"fmt"
)

var jsonStr = `{"Name":"于谦","Age":50,"Rmb":123.45,"Sex":true,"Hobby":["抽烟","喝酒","烫头"]}`

func main() {
    
	type Person struct {
    
		Name  string
		Age   int
		Rmb   float64
		Sex   bool
		Hobby []string
	}

	jsonBytes := []byte(jsonStr)
	personPtr := new(Person)

	err := json.Unmarshal(jsonBytes, personPtr)
	if err != nil {
    
		fmt.Println("反序列化失败，err=", err)
		return
	}
	fmt.Println(*personPtr)
}

2）JSON转map数据

package main

import (
	"encoding/json"
	"fmt"
)

var jsonStr = `{"Name":"于谦","Age":50,"Rmb":123.45,"Sex":true,"Hobby":["抽烟","喝酒","烫头"]}`

func main() {
    
	jsonBytes := []byte(jsonStr)
	dataMap := make(map[string]interface{
    })
	err := json.Unmarshal(jsonBytes, &dataMap)
	if err != nil {
    
		fmt.Println("反序列化失败，err=", err)
		return
	}
	fmt.Println(dataMap)
}

3）JSON转切片数据

package main

import (
	"encoding/json"
	"fmt"
)

func main() {
    
	jsonStr := `[{"hobby":["抽中华","喝牛栏山","烫花卷头"],"name":"王钢蛋"},{"hobby":["抽玉溪","喝五粮液","烫杀马特"],"name":"王铁蛋"},{"hobby":["抽小熊猫","喝剑南春","烫鸡冠头"],"name":"王铜蛋"}]`
	jsonBytes := []byte(jsonStr)
	dataSlice := make([]map[string]interface{
    }, 0)

	err := json.Unmarshal(jsonBytes, &dataSlice)
	if err != nil {
    
		fmt.Println("反序列化失败，err=", err)
		return
	}
	fmt.Println(dataSlice)
}

读写JSON文件

1、编码

1）将map数据转为JSON编码数据写入到JSON文件中

package main

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

func main() {
    
	dataMap := make(map[string]interface{
    })
	dataMap["name"] = "于谦"
	dataMap["age"] = 50
	dataMap["rmb"] = 123.45
	dataMap["sex"] = true
	dataMap["hobby"] = []string{
    "抽烟", "喝酒", "烫头"}

	//创建并打开目标JSON文件
	dstFile, _ := os.OpenFile("D:/go_work/src/demo/1.json", os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0666)
	defer dstFile.Close()

	//创建目标文件的编码器
	encoder := json.NewEncoder(dstFile)

	//将Go语言数据编码到JSON文件
	err := encoder.Encode(dataMap)

	//判断编码是否成功
	if err != nil {
    
		fmt.Println("编码数据到JSON文件失败,err=", err)
		return
	}
	fmt.Println("编码成功！")
}

2）将结构体切片数据转为JSON编码数据写入到JSON文件中

package main

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

func main() {
    
	type Person struct {
    
		Name  string
		Age   int
		Rmb   float64
		Sex   bool
		Hobby []string
	}
	p1 := Person{
    "王钢蛋", 30, 123.45, false, []string{
    "抽中华", "喝农夫山泉", "烫芋头"}}
	p2 := Person{
    "王铁蛋", 30, 123.45, false, []string{
    "抽玉溪", "喝乐百氏", "烫手"}}
	p3 := Person{
    "王铜蛋", 30, 123.45, false, []string{
    "抽黄金叶", "喝三鹿牛奶", "烫光头"}}

	people := make([]Person, 0)
	people = append(people, p1, p2, p3)

	dstFile, _ := os.OpenFile("D:/go_work/src/demo/2.json", os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
	defer dstFile.Close()

	encoder := json.NewEncoder(dstFile)
	err := encoder.Encode(people)

	//判断编码是否成功
	if err != nil {
    
		fmt.Println("编码数据到JSON文件失败,err=", err)
		return
	}
	fmt.Println("编码成功！")
}

2、解码

1）将JSON文件中的数据读取成map数据

package main

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

func main() {
    
	//打开存储JSON数据的源文件
	srcFile, _ := os.Open("D:/go_work/src/demo/1.json")
	defer srcFile.Close()

	//创建map，用于接收解码好的数据
	dataMap := make(map[string]interface{
    })

	//创建源文件的解码器
	decoder := json.NewDecoder(srcFile)

	//解码源文件中的数据，丢入dataMap所在的内存
	err := decoder.Decode(&dataMap)

	//获取解码结果
	if err != nil {
    
		fmt.Println("解码失败，err=", err)
		return
	}
	fmt.Println("解码成功:", dataMap)
}
fmt.Println("解码成功:", dataMap)
}

2）将JSON文件中的数据读取成切片数据
要注意数据是否适合转切片

package main

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

func main() {
    
	type Person struct {
    
		Name  string
		Age   int
		Rmb   float64
		Sex   bool
		Hobby []string
	}

	//打开存储JSON数据的源文件
	srcFile, _ := os.Open("D:/go_work/src/demo/2.json")
	defer srcFile.Close()

	//创建用于接数据的变量
	people := make([]Person, 0)

	//创建源文件的解码器
	decoder := json.NewDecoder(srcFile)

	//解码源文件中的数据，丢入dataMap所在的内存
	err := decoder.Decode(&people)

	//获取解码结果
	if err != nil {
    
		fmt.Println("解码失败，err=", err)
		return
	}
	fmt.Println("解码成功:", people)
}