1.*和&的区别 & 是取地址符号 , 即取得某个变量的地址 , 如 &a
是指针运算符 , 可以表示一个变量是指针类型 , 也可以表示一个指针变量所指向的存储单元 , 也就是这个地址所存储的值
参考：Go中*和&区别
println打印对象只能打印出其指针，需要使用fmt.Printf，如下
1 2 fmt.Printf("%+v\n", user)
参考：Golang 通过fmt包输出完整struct信息
2.defer defer是Go语言提供的一种用于注册延迟调用的机制：让函数或语句可以在当前函数执行完毕后（包括通过return正常结束或者panic导致的异常结束）执行。
defer语句通常用于一些成对操作的场景：打开连接/关闭连接；加锁/释放锁；打开文件/关闭文件等。
defer在一些需要回收资源的场景非常有用，可以很方便地在函数结束前做一些清理操作。在打开资源语句的下一行，直接一句defer就可以在函数返回前关闭资源，可谓相当优雅。
1 2 3 f, _ := os.Open("defer.txt") defer f.Close()
参考：Golang之轻松化解defer的温柔陷阱
3.日志库 1 2 go get -u github.com/sirupsen/logrus
文档
1 2 https://pkg.go.dev/github.com/sirupsen/logrus#section-readme
使用
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 package main import ( "os" "github.com/sirupsen/logrus" ) // Create a new instance of the logger. You can have any number of instances. var log = logrus.New() func main() { // The API for setting attributes is a little different than the package level // exported logger. See Godoc. log.Out = os.Stdout // You could set this to any `io.Writer` such as a file // file, err := os.OpenFile("logrus.log", os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666) // if err == nil { // log.Out = file // } else { // log.Info("Failed to log to file, using default stderr") // } log.WithFields(logrus.Fields{ "animal": "walrus", "size": 10, }).Info("A group of walrus emerges from the ocean") }
1 2 go get -u github.com/rs/zerolog/log
使用
1 2 3 4 5 log.Logger = log.With().Caller().Logger() log.Info().Msg("hello world") // Output: {"level": "info", "message": "hello world", "caller": "/go/src/your_project/some_file:21"}
3.uber/zap 1 2 go get -u go.uber.org/zap
文档
1 2 https://pkg.go.dev/go.uber.org/zap
zap提供了2种logger，分别是Logger和SugaredLogger
在性能要求高但是不是很重要的场景下，适合使用SugaredLogger
1 2 3 4 5 6 7 8 9 10 11 logger, _ := zap.NewProduction() defer logger.Sync() // flushes buffer, if any sugar := logger.Sugar() sugar.Infow("failed to fetch URL", // Structured context as loosely typed key-value pairs. "url", url, "attempt", 3, "backoff", time.Second, ) sugar.Infof("Failed to fetch URL: %s", url)
输出
1 2 3 {"level":"info","ts":1703922949.209576,"caller":"server/main.go:109","msg":"failed to fetch URL","url":"http://example.com","attempt":3,"backoff":1} {"level":"info","ts":1703922949.209731,"caller":"server/main.go:115","msg":"Failed to fetch URL: http://example.com"}
在性能要求高且需要类型安全的场景下，适合使用Logger
1 2 3 4 5 6 7 8 9 10 logger, _ := zap.NewProduction() defer logger.Sync() url := "http://example.com" logger.Info("failed to fetch URL", // Structured context as strongly typed Field values. zap.String("url", url), zap.Int("attempt", 3), zap.Duration("backoff", time.Second), )
输出
1 2 {"level":"info","ts":1703923022.603034,"caller":"server/main.go:108","msg":"failed to fetch URL","url":"http://example.com","attempt":3,"backoff":1}
NewExample/NewDevelopment/NewProduction区别
NewExample适用于测试代码，它将DebugLevel及以上级别的日志以JSON格式标准输出，但省略了时间戳和调用函数，以保持示例输出简短和确定。
NewDevelopment适用于开发环境，它以人类友好的格式将DebugLevel及以上级别的日志写入标准错误。
NewProduction适用于生产环境，它将info level及以上级别的日志以JSON格式写入标准错误。
其他参考文档：Go 每日一库之 zap
golang常用库包：log日志记录-uber的Go日志库zap使用详解
参考：go各框架的log日志
5.日志文件回滚 日志文件按时间回滚：natefinch/lumberjack
1 2 go get gopkg.in/natefinch/lumberjack.v2
4.strconv包 int转string
int64转string
1 2 s := strconv.FormatInt(i, 10)
string转int
1 2 i, err := strconv.Atoi(s)
string转int64
1 2 i, err := strconv.ParseInt(s, 10, 64)
float转string
1 2 3 4 v := 3.1415926535 s1 := strconv.FormatFloat(v, 'E', -1, 32)//float32 s2 := strconv.FormatFloat(v, 'E', -1, 64)//float64
string转float
1 2 3 4 s := "3.1415926535" v1, err := strconv.ParseFloat(v, 32) v2, err := strconv.ParseFloat(v, 64)
参考：Go语言从入门到精通 - 【精华篇】strconv包详解
5.属性复制 可以使用 jinzhu/copier
使用jinzhu/copier
1 2 go get github.com/jinzhu/copier
copy
1 2 copier.Copy(&employee, &user)
deepcopy，区别是deepcopy的时候，对dst的属性进行修改，是肯定不会影响src的
1 2 3 var dst User copier.CopyWithOption(&dst, src, copier.Option{DeepCopy: true})
如果想在复制的时候，对属性进行修改，可以使用方法赋值，注意需要使用copier.Copy，如下
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 type User struct { Name string Age int } func (u *User) DoubleAge() int { return 2 * u.Age } type Employee struct { Name string DoubleAge int Role string } func main() { user := User{Name: "dj", Age: 18} employee := Employee{} copier.Copy(&employee, &user) fmt.Printf("%#v\n", employee) }
参考：Go 每日一库之 copier
其他类似的库还有ulule/deepcoper，参考：golang struct拷贝工具（类似于java中 BeanUtils.copyProperties()）
以及
1 2 3 4 5 6 7 8 9 10 11 12 13 https://github.com/jinzhu/copier https://github.com/mohae/deepcopy https://github.com/ulule/deepcopier https://github.com/mitchellh/copystructure https://github.com/globusdigital/deep-copy https://github.com/getlantern/deepcopy https://github.com/antlabs/deepcopy https://github.com/go-toolsmith/astcopy https://github.com/qdm12/reprint https://github.com/huandu/go-clone https://github.com/wzshiming/deepclone https://github.com/davidwalter0/go-clone
6.其他数据结构 golang没有set，priorityqueue这些数据结构，可以使用emirpasic/gods
参考：https://github.com/emirpasic/gods
7.切片处理 可以使用samber/lo
1 2 go get github.com/samber/lo@v1
比如filter操作
1 2 3 4 5 even := lo.Filter([]int{1, 2, 3, 4}, func(x int, index int) bool { return x%2 == 0 }) // []int{2, 4}
map操作
1 2 3 4 5 6 7 import "github.com/samber/lo" lo.Map([]int64{1, 2, 3, 4}, func(x int64, index int) string { return strconv.FormatInt(x, 10) }) // []string{"1", "2", "3", "4"}
去重操作
1 2 3 uniqValues := lo.Uniq([]int{1, 2, 2, 1}) // []int{1, 2}
获得map的key，并转换成数组
不使用lo
1 2 3 4 5 6 7 8 9 m := map[string]int{ "foo": 1, "bar": 2, } keys := make([]string, 0, len(m)) for key := range m { keys = append(keys, key) }
使用lo
1 2 3 4 5 6 7 8 9 m := map[string]int{ "foo": 1, "bar": 2, } keys := lo.Keys[string, int](m) fmt.Println(keys) // [foo bar]
range操作
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 result := lo.Range(4) // [0, 1, 2, 3] result := lo.Range(-4) // [0, -1, -2, -3] result := lo.RangeFrom(1, 5) // [1, 2, 3, 4, 5] result := lo.RangeFrom[float64](1.0, 5) // [1.0, 2.0, 3.0, 4.0, 5.0] result := lo.RangeWithSteps(0, 20, 5) // [0, 5, 10, 15] result := lo.RangeWithSteps[float32](-1.0, -4.0, -1.0) // [-1.0, -2.0, -3.0] result := lo.RangeWithSteps(1, 4, -1) // [] result := lo.Range(0) // []
8.时间处理 可以使用time或者carbon
1.time 字符串转time.Time
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 import ( "fmt" "time" ) func main() { timeStr := "2023-07-21 14:30:00" // DateTime = "2006-01-02 15:04:05" // DateOnly = "2006-01-02" // TimeOnly = "15:04:05" // RFC3339 = "2006-01-02T15:04:05Z07:00" parsedTime, err := time.Parse(time.DateTime, timeStr) if err != nil { fmt.Println("解析时间字符串时出错:", err) return } fmt.Println("解析后的时间:", parsedTime) }
time.Time转字符串
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 import ( "fmt" "time" ) func main() { // 获取当前时间 currentTime := time.Now() // DateTime = "2006-01-02 15:04:05" // DateOnly = "2006-01-02" // TimeOnly = "15:04:05" // RFC3339 = "2006-01-02T15:04:05Z07:00" timeStr := currentTime.Format(time.DateOnly) // 输出格式化后的时间字符串 fmt.Println("格式化后的时间字符串:", timeStr) }
2.carbon 1 2 go get -u github.com/golang-module/carbon/v2
文档
1 2 https://pkg.go.dev/github.com/golang-module/carbon/v2
9.断言 可以使用stretchr/testify
1 2 go get -u github.com/stretchr/testify
使用assert
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 import ( "testing" "github.com/stretchr/testify/assert" ) func TestSomething(t *testing.T) { // assert equality assert.Equal(t, 123, 123, "they should be equal") // assert inequality assert.NotEqual(t, 123, 456, "they should not be equal") // assert for nil (good for errors) assert.Nil(t, object) // assert for not nil (good when you expect something) if assert.NotNil(t, object) { // now we know that object isn't nil, we are safe to make // further assertions without causing any errors assert.Equal(t, "Something", object.Value) } }
10.resty 在go中请求接口可以使用go-resty/resty 框架
1 2 go get github.com/go-resty/resty/v2
get请求
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 // Create a Resty Client client := resty.New() resp, err := client.R(). SetQueryParams(map[string]string{ "page_no": "1", "limit": "20", "sort":"name", "order": "asc", "random":strconv.FormatInt(time.Now().Unix(), 10), }). SetHeader("Accept", "application/json"). SetResult(&Result{}). SetAuthToken("BC594900518B4F7EAC75BD37F019E08FBC594900518B4F7EAC75BD37F019E08F"). Get("/search_result")
post请求
1 2 3 4 5 6 7 8 9 10 11 // Create a Resty Client client := resty.New() // POST JSON string // No need to set content type, if you have client level setting resp, err := client.R(). SetHeader("Content-Type", "application/json"). SetBody(`{"username":"testuser", "password":"testpass"}`). SetResult(&AuthSuccess{}). // or SetResult(AuthSuccess{}). Post("https://myapp.com/login")
11.单元测试 使用testing框架进行单元测试
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 package dao import ( "fmt" "gin-template/internal/database" "gin-template/internal/model" "testing" ) func Test_userDo_Create(t *testing.T) { user := model.User{ Username: "test", Email: "test@test", } SetDefault(database.DB) err := User.Create(&user) if err != nil { fmt.Println("creat user") } }
如果遇到go testing flag provided but not defined: -test.v的报错，解决方法是添加一个init.go文件
1 2 3 4 5 6 7 8 package test import "testing" func init() { testing.Init() }
然后在使用了flag的地方添加的import中
1 2 _ "gin-template/internal/test"
参考：问题记录：flag provided but not defined: -test.v 异常处理过程
12.打桩工具——go monkey go monkey可以用于在单元测试中进行打桩（指补齐未实现的代码）
参考：Go单测从零到溜系列4—使用monkey打桩
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