golang struct转化成map

迷南。 2023-06-15 11:05 14阅读 0赞

常见的struct转化可以通过json先转换成字符串，然后再转换成map对象。

现在介绍的反射的方式，其中需要注意的是，反射不能够获取struct中没有被暴露出的变量（小写开头的变量）。

好，下面上货。

package demo
    
    import (
    	"fmt"
    	"reflect"
    	"testing"
    	"time"
    )
    
    type CommonObj struct {
    	Name           string    `persistence:"name"`
    	Age            int       `persistence:"age"`
    	LastUpdateTime time.Time `persistence:"lastUpdateTime"`
    	score          float64   `persistence:"-"`
    }
    
    func StructConvertMapByTag(obj interface{}, tagName string) map[string]interface{} {
    	t := reflect.TypeOf(obj)
    	v := reflect.ValueOf(obj)
    
    	var data = make(map[string]interface{})
    	for i := 0; i < t.NumField(); i++ {
    		tagName := t.Field(i).Tag.Get(tagName)
    		fmt.Println(tagName)
    		if tagName != "" && tagName != "-" {
    			data[tagName] = v.Field(i).Interface()
    		}
    	}
    	return data
    }
    
    func TestS(t *testing.T) {
    	obj := CommonObj{
    		Name:           "aa",
    		Age:            12,
    		LastUpdateTime: time.Now(),
    		score:          1.2,
    	}
    
    	m := StructConvertMapByTag(obj, "persistence")
    	fmt.Println(m)
    
    }

运行结果：

=== RUN   TestS
    name
    age
    lastUpdateTime
    -
    map[age:12 lastUpdateTime:2019-11-22 00:58:27.207908 +0800 CST m=+0.000945323 name:aa]
    --- PASS: TestS (0.00s)
    PASS
    
    Process finished with exit code 0

下面是使用json进行转换的实例，可以看到，json在抓换的时候也是忽略没有暴露的字段的（小写字母开头的变量）

package demo
    
    import (
    	"encoding/json"
    	"fmt"
    	"reflect"
    	"testing"
    	"time"
    )
    
    type CommonObj struct {
    	Name           string    `persistence:"name" json:"name"`
    	Age            int       `persistence:"age" json:"age"`
    	LastUpdateTime time.Time `persistence:"lastUpdateTime" json:"last_update_time"`
    	score          float64   `persistence:"-" json:"score"`
    }
    
    func StructConvertMapByTag(obj interface{}, tagName string) map[string]interface{} {
    	t := reflect.TypeOf(obj)
    	v := reflect.ValueOf(obj)
    
    	var data = make(map[string]interface{})
    	for i := 0; i < t.NumField(); i++ {
    		tagName := t.Field(i).Tag.Get(tagName)
    		fmt.Println(tagName)
    		if tagName != "" && tagName != "-" {
    			data[tagName] = v.Field(i).Interface()
    		}
    	}
    	return data
    }
    
    func TestS(t *testing.T) {
    	obj := CommonObj{
    		Name:           "aa",
    		Age:            12,
    		LastUpdateTime: time.Now(),
    		score:          1.2,
    	}
    	m := StructConvertMapByTag(obj, "persistence")
    	fmt.Println(m)
    	bytes, _ := json.Marshal(obj)
    	fmt.Println(string(bytes))
    	var obj2 CommonObj
    	json.Unmarshal(bytes, &obj2)
    	fmt.Println(obj2)
    }

运行结果：

=== RUN   TestS
    name
    age
    lastUpdateTime
    -
    map[age:12 lastUpdateTime:2019-11-22 01:01:13.6298 +0800 CST m=+0.000996209 name:aa]
    {"name":"aa","age":12,"last_update_time":"2019-11-22T01:01:13.6298+08:00"}
    {aa 12 2019-11-22 01:01:13.6298 +0800 CST 0}
    --- PASS: TestS (0.00s)
    PASS