The reflection of Golang
First, about reflection
- The reflection function has a powerful function
- Reflection is the ability to programmatically examine the structure, especially the type, it has
- This is a form of metaprogramming
- We can analyze a structure at run time by reflection
- Check its types and variables (types and values) and methods
- Dynamically modify variables and invoke methods
- This is especially useful for packages without source code
- It’s a powerful tool,
Here is the source code for exporting goods to a specific JSON file
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(a) {
products := make([]interface{},0)
products = append(products, Computer{"Destroyer".9.9."i7".32.2048})
products = append(products, Tshirt{"Bad clothes Bank".88."Red".40.false})
products = append(products, "Tesla".237811.5."Hybrid oil and electric")
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("Success")
return true
}else{
fmt.Println("Failure")
return false}}Copy the codeThe command output is successful.
Here is the output JSON file
We can then go to www.json.cn/ to see the formatted JSON.
Export the product to a JSON file with the same name
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(a) {
products := make([]interface{},0)
products = append(products, Computer{"Destroyer".9.9."i7".32.2048})
products = append(products, Tshirt{"Bad clothes Bank".88."Red".40.false})
products = append(products, Car{"Tesla".237811.5."Hybrid oil and electric"})
for _,p := range products{
pValue := reflect.ValueOf(p)
name := pValue.FieldByName("Name").Interface()
fmt.Println(name)
EncodeObjToJsonFile(p,"E: \ \ block chain palace road \ \ 01.0 _Go language - 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("Success")
return true
}else{
fmt.Println("Failure")
return false}}Copy the codeYou can see that three JSON files appear in the folder.
4. Optimized code
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{" destroy ",9.9},"i7",32,2048}) products = append(products, &tshirt {Product{" Product ",88},"Red",40,false}) products = append(products, &car {Product{"Tesla",237811},5," Tesla"}) for _,p := range products{// pValue := reflect.valueof (p) // name := pValue.FieldByName("Name").Interface() // fmt.Println(name) // EncodeObjToJsonFile(p,"E:\\ Path to blockchain \\ 01.0_GO Language foundation -v3.0\\code\\ SRC \jsonFile\\"+ name.(string) +".json") EncodeObjToJsonFile(p,"E:\\ path to blockchain palace \\ 01.0_GO Language foundation -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(" success ") return true}else{FMT.Println(" failure ") 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{" Product ",9.9},"i7",32,2048}) products = append(products, &tshirt {Product{" Product ",88},"Red",40,false}) products = append(products, &car {Product{"Tesla",237811},5," Tesla"}) for _,p := range products{// pValue := reflect.valueof (p) // name := pValue.FieldByName("Name").Interface() // fmt.Println(name) // EncodeObjToJsonFile(p,"E:\\ Path to blockchain \\ 01.0_GO Language foundation -v3.0\\code\\ SRC \jsonFile\\"+ name.(string) +".json") EncodeObjToJsonFile(p,"E:\\ path to blockchain palace \\ 01.0_GO Language foundation -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{ Println(" success ") return true}else{FMT.Println(" failure ") return false}}Copy the codeUse of GoBench [Go Study Notes] | Go Theme month juejin.cn/post/694346…
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