[golang]读取常见配置文件
前言
主要介绍 yaml、toml、json、ini格式文件的配置读取。
除了以下方式，更方便的做法是用viper，不过配置结构可能不会很清晰。
YAML
假设yaml文件内容如下
# 基本键值对
string_key: "这是一个字符串"
integer_key: 42
float_key: 3.14
boolean_key: true
null_key: null
# 列表（数组）
simple_list:
- item1
- item2
- item3
nested_list:
-
- sub_item1
- sub_item2
-
- sub_item3
- sub_item4
# 字典（映射）
simple_dict:
key1: value1
key2: value2
nested_dict:
outer_key1:
inner_key1: inner_value1
inner_key2: inner_value2
outer_key2:
inner_key3: inner_value3
# 引用 & 锚点
defaults: &default_settings
version: 1.0
enabled: true
service1:
<<: *default_settings
name: "Service One"
service2:
<<: *default_settings
name: "Service Two"
enabled: false # 覆盖默认值
# 多行字符串
multiline_string: |
这是一个多行字符串。
第二行。
第三行。
folded_string: >
这是一个折叠字符串，
换行会被转换为一个空格。
# 混合数据结构
complex_structure:
- name: "Item1"
attributes:
color: "red"
size: "L"
- name: "Item2"
attributes:
color: "blue"
size: "M"
# 带注释的值
annotated_key: "值 # 这是注释"
# 日期和时间
date_key: 2024-12-18
datetime_key: 2024-12-18T12:34:56Z
# 特殊类型
binary_data: !!binary |
VGhpcyBpcyBhIGJpbmFyeSBkYXRhLg==
custom_type: !!map
key1: value1
key2: value2
读取的go示例代码
package main
import (
"fmt"
"log"
"os"
"gopkg.in/yaml.v3"
)
type Config struct {
StringKey string `yaml:"string_key"`
IntegerKey int `yaml:"integer_key"`
FloatKey float64 `yaml:"float_key"`
BooleanKey bool `yaml:"boolean_key"`
NullKey interface{} `yaml:"null_key"`
SimpleList []string `yaml:"simple_list"`
NestedList [][]string `yaml:"nested_list"`
SimpleDict map[string]string `yaml:"simple_dict"`
NestedDict map[string]map[string]string `yaml:"nested_dict"`
Defaults Defaults `yaml:"defaults"`
Service1 Service `yaml:"service1"`
Service2 Service `yaml:"service2"`
MultilineString string `yaml:"multiline_string"`
FoldedString string `yaml:"folded_string"`
ComplexStructure []Item `yaml:"complex_structure"`
AnnotatedKey string `yaml:"annotated_key"`
DateKey string `yaml:"date_key"`
DatetimeKey string `yaml:"datetime_key"`
BinaryData string `yaml:"binary_data"`
CustomType map[string]string `yaml:"custom_type"`
}
type Defaults struct {
Version string `yaml:"version"`
Enabled bool `yaml:"enabled"`
}
type Service struct {
Defaults
Name string `yaml:"name"`
}
type Item struct {
Name string `yaml:"name"`
Attributes map[string]string `yaml:"attributes"`
}
func ReadYaml(filepath string) {
file, err := os.ReadFile(filepath)
if err != nil {
log.Fatalf("Error reading config file, %s\n", err)
}
var cfg Config
err = yaml.Unmarshal(file, &cfg)
if err != nil {
log.Fatalf("Error parsing config file, %s\n", err)
}
fmt.Printf("%+v\n", cfg)
}
toml
假设toml文件内容如下
# 基本键值对
string_key = "这是一个字符串"
integer_key = 42
float_key = 3.14
boolean_key = true
# TOML 不支持 null，可以用空字符串或省略键值表示 null
null_key = ""
# 列表（数组）
simple_list = ["item1", "item2", "item3"]
nested_list = [
["sub_item1", "sub_item2"],
["sub_item3", "sub_item4"]
]
# 字典（表）
[simple_dict]
key1 = "value1"
key2 = "value2"
[nested_dict.outer_key1]
inner_key1 = "inner_value1"
inner_key2 = "inner_value2"
[nested_dict.outer_key2]
inner_key3 = "inner_value3"
# 多行字符串
multiline_string = """
这是一个多行字符串。
第二行。
第三行。
"""
folded_string = """这是一个折叠字符串，换行会被转换为一个空格。"""
# 混合数据结构
[[complex_structure]]
name = "Item1"
[complex_structure.attributes]
color = "red"
size = "L"
[[complex_structure]]
name = "Item2"
[complex_structure.attributes]
color = "blue"
size = "M"
示例代码
package main
import (
"fmt"
"log"
"os"
"github.com/pelletier/go-toml/v2"
)
// 定义与 TOML 结构对应的 Go 数据结构
type TomlConfig struct {
StringKey string `toml:"string_key"`
IntegerKey int `toml:"integer_key"`
FloatKey float64 `toml:"float_key"`
BooleanKey bool `toml:"boolean_key"`
NullKey string `toml:"null_key"`
SimpleList []string `toml:"simple_list"`
NestedList [][]string `toml:"nested_list"`
SimpleDict map[string]string `toml:"simple_dict"`
NestedDict map[string]map[string]string `toml:"nested_dict"`
MultilineString string `toml:"multiline_string"`
FoldedString string `toml:"folded_string"`
ComplexStructure []ComplexItem `toml:"complex_structure"`
}
type ComplexItem struct {
Name string `toml:"name"`
Attributes map[string]string `toml:"attributes"`
}
func ReadToml(filepath string) {
file, err := os.ReadFile(filepath)
if err != nil {
log.Fatalf("读取文件失败: %v", err)
}
// 定义存储解析数据的变量
var config TomlConfig
// 解析 TOML 文件
if err := toml.Unmarshal(file, &config); err != nil {
log.Fatalf("解析 TOML 文件失败: %v", err)
}
// 打印解析结果
fmt.Printf("读取的配置:\n%+v\n", config)
}
json
json文件内容如下，是从上面toml文件转换而来
{
"string_key": "这是一个字符串",
"integer_key": 42,
"float_key": 3.14,
"boolean_key": true,
"null_key": null,
"simple_list": [
"item1",
"item2",
"item3"
],
"nested_list": [
[
"sub_item1",
"sub_item2"
],
[
"sub_item3",
"sub_item4"
]
],
"simple_dict": {
"key1": "value1",
"key2": "value2"
},
"nested_dict": {
"outer_key1": {
"inner_key1": "inner_value1",
"inner_key2": "inner_value2"
},
"outer_key2": {
"inner_key3": "inner_value3"
}
},
"multiline_string": "这是一个多行字符串。\n第二行。\n第三行。\n",
"folded_string": "这是一个折叠字符串， 换行会被转换为一个空格。\n",
"complex_structure": [
{
"name": "Item1",
"attributes": {
"color": "red",
"size": "L"
}
},
{
"name": "Item2",
"attributes": {
"color": "blue",
"size": "M"
}
}
]
}
Go示例代码，结构体定义复用上面toml的
package main
import (
"encoding/json"
"fmt"
"log"
"os"
)
type TomlConfig struct {
StringKey string `toml:"string_key" json:"string_key"`
IntegerKey int `toml:"integer_key" json:"integer_key"`
FloatKey float64 `toml:"float_key" json:"float_key"`
BooleanKey bool `toml:"boolean_key" json:"boolean_key"`
NullKey string `toml:"null_key" json:"null_key"`
SimpleList []string `toml:"simple_list" json:"simple_list"`
NestedList [][]string `toml:"nested_list" json:"nested_list"`
SimpleDict map[string]string `toml:"simple_dict" json:"simple_dict"`
NestedDict map[string]map[string]string `toml:"nested_dict" json:"nested_dict"`
MultilineString string `toml:"multiline_string" json:"multiline_string"`
FoldedString string `toml:"folded_string" json:"folded_string"`
ComplexStructure []ComplexItem `toml:"complex_structure" json:"complex_structure"`
}
type ComplexItem struct {
Name string `toml:"name" json:"name"`
Attributes map[string]string `toml:"attributes" json:"attributes"`
}
func ReadJson(filepath string) {
file, err := os.Open(filepath)
if err != nil {
log.Fatalf("Error reading config file, %s\n", err)
}
defer file.Close()
var cfg TomlConfig
decoder := json.NewDecoder(file)
err = decoder.Decode(&cfg)
if err != nil {
log.Fatalf("Error parsing config file, %s\n", err)
}
fmt.Printf("%+v\n", cfg)
}
ini
ini文件内容如下
[database]
dbtype: "postgres"
dbname: "test"
dbhost: "localhost"
dbport: "5432"
dbuser: "postgres"
dbpass: "postgres"
[log]
logdir: "/var/log/goapp"
days: 7
go示例代码
package main
import (
"fmt"
"log"
"gopkg.in/ini.v1"
)
type IniConfig struct {
Database DatabaseConfig `ini:"database"`
Log LogConfig `ini:"log"`
}
type DatabaseConfig struct {
DBType string `ini:"dbtype"`
DBName string `ini:"dbname"`
DBHost string `ini:"dbhost"`
DBPort string `ini:"dbport"`
DBUser string `ini:"dbuser"`
DBPass string `ini:"dbpass"`
}
type LogConfig struct {
LogDir string `ini:"logdir"`
Days int `ini:"days"`
}
func ReadIni(filepath string) {
cfg, err := ini.Load(filepath)
if err != nil {
log.Fatalf("Error reading config file, %s\n", err)
}
var config IniConfig
err = cfg.MapTo(&config)
if err != nil {
log.Fatalf("Error parsing config file, %s\n", err)
}
fmt.Printf("%+v\n", config)
}
本文来自博客园，作者：花酒锄作田，转载请注明原文链接：https://www.cnblogs.com/XY-Heruo/p/18616036
