golang操作yaml
// 可以用于处理读yaml格式的配置文件，同时也可以用于理解golang中的反射
package config_yaml
import (
"strings"
"errors"
"io/ioutil"
"gopkg.in/yaml.v2"
"reflect"
"fmt"
"strconv"
)
type ConfigEngine struct {
data map[interface{}]interface{}
}
// 将ymal文件中的内容进行加载
func (c *ConfigEngine) Load (path string) error {
ext := c.guessFileType(path)
if ext == "" {
return errors.New("cant not load" + path + " config")
}
return c.loadFromYaml(path)
}
//判断配置文件名是否为yaml格式
func (c *ConfigEngine) guessFileType(path string) string {
s := strings.Split(path,".")
ext := s[len(s) - 1]
switch ext {
case "yaml","yml":
return "yaml"
}
return ""
}
// 将配置yaml文件中的进行加载
func (c *ConfigEngine) loadFromYaml(path string) error {
yamlS,readErr := ioutil.ReadFile(path)
if readErr != nil {
return readErr
}
// yaml解析的时候c.data如果没有被初始化，会自动为你做初始化
err := yaml.Unmarshal(yamlS, &c.data)
if err != nil {
return errors.New("can not parse "+ path + " config" )
}
return nil
}
// 从配置文件中获取值
func (c *ConfigEngine) Get(name string) interface{}{
path := strings.Split(name,".")
data := c.data
for key, value := range path {
v, ok := data[value]
if !ok {
break
}
if (key + 1) == len(path) {
return v
}
if reflect.TypeOf(v).String() == "map[interface {}]interface {}"{
data = v.(map[interface {}]interface {})
}
}
return nil
}
// 从配置文件中获取string类型的值
func (c *ConfigEngine) GetString(name string) string {
value := c.Get(name)
switch value:=value.(type){
case string:
return value
case bool,float64,int:
return fmt.Sprint(value)
default:
return ""
}
}
// 从配置文件中获取int类型的值
func (c *ConfigEngine) GetInt(name string) int {
value := c.Get(name)
switch value := value.(type){
case string:
i,_:= strconv.Atoi(value)
return i
case int:
return value
case bool:
if value{
return 1
}
return 0
case float64:
return int(value)
default:
return 0
}
}
// 从配置文件中获取bool类型的值
func (c *ConfigEngine) GetBool(name string) bool {
value := c.Get(name)
switch value := value.(type){
case string:
str,_:= strconv.ParseBool(value)
return str
case int:
if value != 0 {
return true
}
return false
case bool:
return value
case float64:
if value != 0.0 {
return true
}
return false
default:
return false
}
}
// 从配置文件中获取Float64类型的值
func (c *ConfigEngine) GetFloat64(name string) float64 {
value := c.Get(name)
switch value := value.(type){
case string:
str,_ := strconv.ParseFloat(value,64)
return str
case int:
return float64(value)
case bool:
if value {
return float64(1)
}
return float64(0)
case float64:
return value
default:
return float64(0)
}
}
// 从配置文件中获取Struct类型的值,这里的struct是你自己定义的根据配置文件
func (c *ConfigEngine) GetStruct(name string,s interface{}) interface{}{
d := c.Get(name)
switch d.(type){
case string:
c.setField(s,name,d)
case map[interface{}]interface{}:
c.mapToStruct(d.(map[interface{}]interface{}), s)
}
return s
}
func (c *ConfigEngine) mapToStruct(m map[interface{}]interface{},s interface{}) interface{}{
for key, value := range m {
switch key.(type) {
case string:
c.setField(s,key.(string),value)
}
}
return s
}
// 这部分代码是重点，需要多看看
func (c *ConfigEngine) setField(obj interface{},name string,value interface{}) error {
// reflect.Indirect 返回value对应的值
structValue := reflect.Indirect(reflect.ValueOf(obj))
structFieldValue := structValue.FieldByName(name)
// isValid 显示的测试一个空指针
if !structFieldValue.IsValid() {
return fmt.Errorf("No such field: %s in obj",name)
}
// CanSet判断值是否可以被更改
if !structFieldValue.CanSet() {
return fmt.Errorf("Cannot set %s field value", name)
}
// 获取要更改值的类型
structFieldType := structFieldValue.Type()
val := reflect.ValueOf(value)
if structFieldType.Kind() == reflect.Struct && val.Kind() == reflect.Map {
vint := val.Interface()
switch vint.(type) {
case map[interface{}]interface{}:
for key, value := range vint.(map[interface{}]interface{}) {
c.setField(structFieldValue.Addr().Interface(), key.(string), value)
}
case map[string]interface{}:
for key, value := range vint.(map[string]interface{}) {
c.setField(structFieldValue.Addr().Interface(), key, value)
}
}
} else {
if structFieldType != val.Type() {
return errors.New("Provided value type didn‘t match obj field type")
}
structFieldValue.Set(val)
}
return nil
}=============================================================================================
更简便的方式：
aaa:
bb: "hahha"
cc:
dd: ["aa", "bb111"]
定义一个基于yaml文件全量的structs
type AllConf struct {
AConf TypeA `yaml:"aaa"`
}
type A struct {
aa string `yaml:"cc"`
}