Go的反射实战：输出商品到同名JSON文件｜Go主题月

菜鸟魔王
367 阅读3分钟

Golang之反射

一、关于反射

  • 反射功能具有强大的功能
  • 反射是用程序检查其所拥有的结构，尤其是类型的一种能力
  • 这是元编程的一种形式
  • 我们可以在运行时通过反射来分析一个结构体
  • 检查其类型和变量（类型和取值）和方法
  • 动态地修改变量和调用方法
  • 这对于没有源代码的包尤其有用
  • 这是一个强大的工具，

二、下面是输出商品到特定JSON文件的源代码

package main

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

type Computer struct {
	Name string
	Price float64
	Cpu string
	Memory int
	Disk int
}
type Tshirt struct {
	Name string
	Price float64
	Color string
	Size int
	Sex bool
}
type Car struct {
	Name string
	Price float64
	Cap int
	Power string
}
func main() {
	products := make([]interface{},0)
	products = append(products, Computer{"破坏者",9.9,"i7",32,2048})
	products = append(products, Tshirt{"差衣库",88,"Red",40,false})
	products = append(products, "Tesla",237811,5,"油电混合")

	EncodeObjToJsonFile(products,"E:\\code\\src\\jsonFile\\products.json")
}

func EncodeObjToJsonFile(objs []interface{},filename string) bool  {
	dstFile, _ := os.OpenFile(filename, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
	defer dstFile.Close()

	encoder := json.NewEncoder(dstFile)
	err := encoder.Encode(objs)
	if err == nil{
		fmt.Println("成功")
		return true
	}else{
		fmt.Println("失败")
		return false
	}
}

运行显示成功。 image.png

下面是输出的JSON文件 image.png

然后我们可以去www.json.cn/ 来查看格式化JSON。

image.png

三、输出商品到同名JSON文件

package main

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

type Computer struct {
	Name string
	Price float64
	Cpu string
	Memory int
	Disk int
}
type Tshirt struct {
	Name string
	Price float64
	Color string
	Size int
	Sex bool
}
type Car struct {
	Name string
	Price float64
	Cap int
	Power string
}
func main() {
	products := make([]interface{},0)
	products = append(products, Computer{"破坏者",9.9,"i7",32,2048})
	products = append(products, Tshirt{"差衣库",88,"Red",40,false})
	products = append(products, Car{"Tesla",237811,5,"油电混合"})
	for _,p := range products{
		pValue := reflect.ValueOf(p)
		name := pValue.FieldByName("Name").Interface()
		fmt.Println(name)
		EncodeObjToJsonFile(p,"E:\\区块链殿堂之路\\01.0_Go语言基础-v3.0\\code\\src\\jsonFile\\"+ name.(string) +".json")
	}

}

func EncodeObjToJsonFile(obj interface{},filename string) bool  {
	dstFile, _ := os.OpenFile(filename, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
	defer dstFile.Close()

	encoder := json.NewEncoder(dstFile)
	err := encoder.Encode(obj)
	if err == nil{
		fmt.Println("成功")
		return true
	}else{
		fmt.Println("失败")
		return false
	}
}

可以看到文件夹中出现了三个JSON文件。

image.png

image.png

四、优化后代码


import (
	"encoding/json"
	"fmt"
	"os"
)
type IProduct interface {
	GetName() string
	GetPrice() float64
}
type Product struct {
	Name string
	Price float64
}

func (p *Product)GetName() string {
	return p.Name
}
func (p *Product)GetPrice() float64 {
	return p.Price
}
type Computer struct {
	//Name string
	//Price float64
	Product
	Cpu string
	Memory int
	Disk int
}
type Tshirt struct {
	//Name string
	//Price float64
	Product
	Color string
	Size int
	Sex bool
}
type Car struct {
	//Name string
	//Price float64
	Product
	Cap int
	Power string
}
func main() {
	products := make([]IProduct,0)
	products = append(products, &Computer{Product{"破坏者",9.9},"i7",32,2048})
	products = append(products, &Tshirt{Product{"差衣库",88},"Red",40,false})
	products = append(products, &Car{Product{"Tesla",237811},5,"油电混合"})
	for _,p := range products{
		//通过反射获得Name的值
	//	pValue := reflect.ValueOf(p)
	//	name := pValue.FieldByName("Name").Interface()
	//	fmt.Println(name)
	//	EncodeObjToJsonFile(p,"E:\\区块链殿堂之路\\01.0_Go语言基础-v3.0\\code\\src\\jsonFile\\"+ name.(string) +".json")
		EncodeObjToJsonFile(p,"E:\\区块链殿堂之路\\01.0_Go语言基础-v3.0\\code\\src\\jsonFile\\"+ p.GetName() +".json")

	}

}

func EncodeObjToJsonFile(obj interface{},filename string) bool  {
	dstFile, _ := os.OpenFile(filename, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
	defer dstFile.Close()

	encoder := json.NewEncoder(dstFile)
	err := encoder.Encode(obj)
	if err == nil{
		fmt.Println("成功")
		return true
	}else{
		fmt.Println("失败")
		return false
	}
}
package main

import (
	"encoding/json"
	"fmt"
	"os"
)
type IProduct interface {
	GetName() string
	GetPrice() float64
}
type Product struct {
	Name string
	Price float64
}

func (p *Product)GetName() string {
	return p.Name
}
func (p *Product)GetPrice() float64 {
	return p.Price
}
type Computer struct {
	//Name string
	//Price float64
	Product
	Cpu string
	Memory int
	Disk int
}
type Tshirt struct {
	//Name string
	//Price float64
	Product
	Color string
	Size int
	Sex bool
}
type Car struct {
	//Name string
	//Price float64
	Product
	Cap int
	Power string
}
func main() {
	products := make([]IProduct,0)
	products = append(products, &Computer{Product{"破坏者",9.9},"i7",32,2048})
	products = append(products, &Tshirt{Product{"差衣库",88},"Red",40,false})
	products = append(products, &Car{Product{"Tesla",237811},5,"油电混合"})
	for _,p := range products{
		//通过反射获得Name的值
	//	pValue := reflect.ValueOf(p)
	//	name := pValue.FieldByName("Name").Interface()
	//	fmt.Println(name)
	//	EncodeObjToJsonFile(p,"E:\\区块链殿堂之路\\01.0_Go语言基础-v3.0\\code\\src\\jsonFile\\"+ name.(string) +".json")
		EncodeObjToJsonFile(p,"E:\\区块链殿堂之路\\01.0_Go语言基础-v3.0\\code\\src\\jsonFile\\"+ p.GetName() +".json")

	}

}

func EncodeObjToJsonFile(obj interface{},filename string) bool  {
	dstFile, _ := os.OpenFile(filename, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
	defer dstFile.Close()

	encoder := json.NewEncoder(dstFile)
	err := encoder.Encode(obj)
	if err == nil{
		fmt.Println("成功")
		return true
	}else{
		fmt.Println("失败")
		return false
	}
}

gobench的使用【Go学习笔记】 ｜Go主题月 juejin.cn/post/694346…

go test的使用【Go 学习笔记】｜Go主题月 juejin.cn/post/694319…

avatar
文章
阅读
粉丝