A simple and easy go tools for auto mapper struct to map, struct to struct, slice to slice, map to slice, map to json.
go get -u github.com/devfeel/mapper
Traditional Usage
package main import ( "fmt" "github.com/devfeel/mapper" ) type ( User struct { Name string Age int Id string `mapper:"_id"` AA string `json:"Score"` Time time.Time } Student struct { Name string Age int Id string `mapper:"_id"` Score string } Teacher struct { Name string Age int Id string `mapper:"_id"` Level string } ) func init() { mapper.Register(&User{}) mapper.Register(&Student{}) } func main() { user := &User{} userMap := &User{} teacher := &Teacher{} student := &Student{Name: "test", Age: 10, Id: "testId", Score: "100"} valMap := make(map[string]interface{}) valMap["Name"] = "map" valMap["Age"] = 10 valMap["_id"] = "x1asd" valMap["Score"] = 100 valMap["Time"] = time.Now() mapper.Mapper(student, user) mapper.AutoMapper(student, teacher) mapper.MapperMap(valMap, userMap) fmt.Println("student:", student) fmt.Println("user:", user) fmt.Println("teacher", teacher) fmt.Println("userMap:", userMap) }
执行main，输出：
student: &{test 10 testId 100}
user: &{test 10 testId 100 0001-01-01 00:00:00 +0000 UTC}
teacher &{test 10 testId }
userMap: &{map 10 x1asd 100 2017-11-20 13:45:56.3972504 +0800 CST m=+0.006004001}
Object Usage
package main import ( "fmt" "github.com/devfeel/mapper" ) type ( User struct { Name string `json:"name" mapper:"name"` Class int `mapper:"class"` Age int `json:"age" mapper:"-"` } Student struct { Name string `json:"name" mapper:"name"` Class int `mapper:"class"` Age []int `json:"age" mapper:"-"` } ) func main() { user := &User{Name: "shyandsy", Class: 1, Age: 10} student := &Student{} // create mapper object m := mapper.NewMapper() // in the version < v0.7.8, we will use field name as key when mapping structs // we keep it as default behavior in this version m.SetEnableIgnoreFieldTag(true) student.Age = []int{1} // disable the json tag m.SetEnabledJsonTag(false) // student::age should be 1 m.Mapper(user, student) fmt.Println("user:") fmt.Println(user) fmt.Println("student:") fmt.Println(student) }
执行main，输出：
user:
&{shyandsy 1 10}
student:
&{shyandsy 1 [1]}
- 支持不同结构体相同名称相同类型字段自动赋值，使用Mapper
- 支持不同结构体Slice的自动赋值，使用MapperSlice
- 支持字段为结构体时的自动赋值
- 支持struct到map的自动映射赋值，使用Mapper
- 支持map到struct的自动映射赋值，使用MapperMap
- 支持map到struct slice的自动赋值，使用MapToSlice
- 支持map与json的互相转换
- 支持Time与Unix自动转换
- 支持tag标签，tag关键字为 mapper
- 兼容json-tag标签
- 当tag为"-"时，将忽略tag定义，使用struct field name
- 无需手动Register struct，内部自动识别
- 支持开启关闭
- SetEnabledTypeChecking(bool) // 类型检查
- IsEnabledTypeChecking
- SetEnabledMapperTag // mapper tag
- IsEnabledMapperTag
- SetEnabledJsonTag // json tag
- IsEnabledJsonTag
- SetEnabledAutoTypeConvert // auto type convert
- IsEnabledAutoTypeConvert
- SetEnabledMapperStructField // mapper struct field
- IsEnabledMapperStructField
Version 0.8 introduces a new set of generic mapping functions with better performance and simpler usage.
| Method | Old | New | Improvement |
|---|---|---|---|
| Single mapping | 3,897 ns/op | 556 ns/op | 7x faster |
| Slice mapping (100 items) | 452,718 ns/op | 59,185 ns/op | 7.6x faster |
| Memory allocation | 400 B/op | 272 B/op | -32% |
| Allocations | 42 allocs/op | 4 allocs/op | -90% |
// Single mapping - direct return result dto := mapper.MapDirect[Source, Target](source) // Pointer version dto := mapper.MapDirectPtr[Source, Target](&source) // Slice mapping dtos := mapper.MapDirectSlice[Source, Target](sources) // Pointer slice mapping dtos := mapper.MapDirectPtrSlice[Source, Target](&sources) // With error handling dto, err := mapper.SafeMapDirect[Source, Target](source) // Slice with error handling dtos, err := mapper.SafeMapDirectSlice[Source, Target](sources)
package main import ( "fmt" "github.com/devfeel/mapper" ) type User struct { ID int64 `mapper:"id"` Name string `mapper:"name"` Age int `mapper:"age"` } type UserDTO struct { ID int64 `json:"id"` Name string `json:"name"` Age int `json:"age"` } func main() { // Single mapping user := User{ID: 1, Name: "Tom", Age: 20} dto := mapper.MapDirect[User, UserDTO](user) fmt.Printf("%+v\n", dto) // Slice mapping users := []User{ {ID: 1, Name: "Tom", Age: 20}, {ID: 2, Name: "Jerry", Age: 25}, } dtos := mapper.MapDirectSlice[User, UserDTO](users) fmt.Printf("%+v\n", dtos) }
Run benchmarks to verify performance:
go test -bench=Benchmark_MapDirect -benchmem -count=3 ./...