type Logger struct {
    mu     sync.Mutex // ensures atomic writes; protects the following fields
    prefix string     // prefix on each line to identify the logger (but see                            Lmsgprefix)
    flag   int        // properties
    out    io.Writer  // destination for output
    buf    []byte     // for accumulating text to write
}

log.Println("這是一條優(yōu)雅的日志。")
v := "優(yōu)雅的"
log.Printf("這是一個%s日志\n", v)
//fatal系列函數(shù)會在寫入日志信息后調(diào)用os.Exit(1)
log.Fatalln("這是一天會觸發(fā)fatal的日志") 
//Panic系列函數(shù)會在寫入日志信息后panic
log.Panicln("這是一個會觸發(fā)panic的日志。") //執(zhí)行后會自動觸發(fā)一個異常

const (
    Ldate    = 1 << iota     // the date in the local time zone: 2009/01/23
    Ltime                    // the time in the local time zone: 01:23:23
    Lmicroseconds           // microsecond resolution: 01:23:23.123123.  assumes Ltime.
    Llongfile               // full file name and line number: /a/b/c/d.go:23
    Lshortfile   // final file name element and line number: d.go:23. overrides Llongfile
    LUTC         // if Ldate or Ltime is set, use UTC rather than the local time zone
    Lmsgprefix  // move the "prefix" from the beginning of the line to before the message
    LstdFlags = Ldate | Ltime // initial values for the standard logger
)

func main() {
    log.SetFlags(log.Llongfile | log.Lmicroseconds | log.Ldate)
    log.Println("這是一條優(yōu)雅的日志。")
}

func Prefix() string
 func SetPrefix(prefix string)

func main() {
    log.SetPrefix("[PS]")
    log.Println("這是一條很普通的日志。")
}

func SetOutput(w io.Writer)

func main() {
    logFile, err := os.OpenFile("./xx.log", os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
    if err != nil {
        fmt.Println("open log file failed, err:", err)
        return
    }
    log.SetOutput(logFile)
    log.SetFlags(log.Llongfile | log.Lmicroseconds | log.Ldate)
    log.Println("這是一條很普通的日志。")
    log.SetPrefix("[PS]")
    log.Println("這是一條很普通的日志。")
}

func init() {
    logFile, err := os.OpenFile("./xx.log", os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
    if err != nil {
        fmt.Println("open log file failed, err:", err)
        return
    }
    log.SetOutput(logFile)
    log.SetFlags(log.Llongfile | log.Lmicroseconds | log.Ldate)
}

func New(out io.Writer, prefix string, flag int) *Logger

func main() {
    logger := log.New(os.Stdout, "<PS>", log.Lshortfile|log.Ldate|log.Ltime)
    logger.Println("這是自定義的logger記錄的日志。")
}

func SetupLogger() {
    logFileLocation, _ := os.OpenFile("./test.log", os.O_CREATE|os.O_APPEND|os.O_RDWR, 0744)
    log.SetOutput(logFileLocation)
}

func test(){
   log.Printf("Test log: %s %s", "Hello", "World")
}

func main() {
    SetupLogger()
  test()
}

go get -u go.uber.org/zap

var logger *zap.Logger

func main() {
    InitLogger()
  defer logger.Sync()
    simpleHttpGet("www.google.com")
    simpleHttpGet("http://www.google.com")
}

func InitLogger() {
    logger, _ = zap.NewProduction()
}

func simpleHttpGet(url string) {
    resp, err := http.Get(url)
    if err != nil {
        logger.Error(
            "Error fetching url..",
            zap.String("url", url),
            zap.Error(err))
    } else {
        logger.Info("Success..",
            zap.String("statusCode", resp.Status),
            zap.String("url", url))
        resp.Body.Close()
    }
}

func (log *Logger) MethodXXX(msg string, fields ...Field)

slogger := logger.Sugar()

var sugarLogger *zap.SugaredLogger

func main() {
    InitLogger()
    defer sugarLogger.Sync()
    simpleHttpGet("www.google.com")
    simpleHttpGet("http://www.google.com")
}

func InitLogger() {
  logger, _ := zap.NewProduction()
    sugarLogger = logger.Sugar()
}

func simpleHttpGet(url string) {
    sugarLogger.Debugf("Trying to hit GET request for %s", url)
    resp, err := http.Get(url)
    if err != nil {
        sugarLogger.Errorf("Error fetching URL %s : Error = %s", url, err)
    } else {
        sugarLogger.Infof("Success! statusCode = %s for URL %s", resp.Status, url)
        resp.Body.Close()
    }
}

func New(core zapcore.Core, options ...Option) *Logger

zapcore.NewJSONEncoder(zap.NewProductionEncoderConfig())

file, _ := os.Create("./test.log")
writeSyncer := zapcore.AddSync(file)

func InitLogger() {
    writeSyncer := getLogWriter()
    encoder := getEncoder()
    core := zapcore.NewCore(encoder, writeSyncer, zapcore.DebugLevel)

    logger := zap.New(core)
    sugarLogger = logger.Sugar()
}

func getEncoder() zapcore.Encoder {
    return zapcore.NewJSONEncoder(zap.NewProductionEncoderConfig())
}

func getLogWriter() zapcore.WriteSyncer {
    file, _ := os.Create("./test.log")
    return zapcore.AddSync(file)
}

return zapcore.NewConsoleEncoder(zap.NewProductionEncoderConfig())

func getEncoder() zapcore.Encoder {
    encoderConfig := zap.NewProductionEncoderConfig()
    encoderConfig.EncodeTime = zapcore.ISO8601TimeEncoder
    encoderConfig.EncodeLevel = zapcore.CapitalLevelEncoder
    return zapcore.NewConsoleEncoder(encoderConfig)
}

logger := zap.New(core, zap.AddCaller())

go get -u github.com/natefinch/lumberjack

func getLogWriter() zapcore.WriteSyncer {
    lumberJackLogger := &lumberjack.Logger{
        Filename:   "./test.log",
        MaxSize:    10,
        MaxBackups: 5,
        MaxAge:     30,
        Compress:   false,
    }
    return zapcore.AddSync(lumberJackLogger)
}

r := gin.New()
r.Use(GinLogger(), GinRecovery())

// GinLogger 接收gin框架默認的日志
func GinLogger(logger *zap.Logger) gin.HandlerFunc {
    return func(c *gin.Context) {
        start := time.Now()
        path := c.Request.URL.Path
        query := c.Request.URL.RawQuery
        c.Next()

        cost := time.Since(start)
        logger.Info(path,
            zap.Int("status", c.Writer.Status()),
            zap.String("method", c.Request.Method),
            zap.String("path", path),
            zap.String("query", query),
            zap.String("ip", c.ClientIP()),
            zap.String("user-agent", c.Request.UserAgent()),
            zap.String("errors", c.Errors.ByType(gin.ErrorTypePrivate).String()),
            zap.Duration("cost", cost),
        )
    }
}

// GinRecovery recover掉項目可能出現(xiàn)的panic
func GinRecovery(logger *zap.Logger, stack bool) gin.HandlerFunc {
    return func(c *gin.Context) {
        defer func() {
            if err := recover(); err != nil {
                // Check for a broken connection, as it is not really a
                // condition that warrants a panic stack trace.
                var brokenPipe bool
                if ne, ok := err.(*net.OpError); ok {
                    if se, ok := ne.Err.(*os.SyscallError); ok {
                        if strings.Contains(strings.ToLower(se.Error()), "broken pipe") || strings.Contains(strings.ToLower(se.Error()), "connection reset by peer") {
                            brokenPipe = true
                        }
                    }
                }

                httpRequest, _ := httputil.DumpRequest(c.Request, false)
                if brokenPipe {
                    logger.Error(c.Request.URL.Path,
                        zap.Any("error", err),
                        zap.String("request", string(httpRequest)),
                    )
                    // If the connection is dead, we can't write a status to it.
                    c.Error(err.(error)) // nolint: errcheck
                    c.Abort()
                    return
                }

                if stack {
                    logger.Error("[Recovery from panic]",
                        zap.Any("error", err),
                        zap.String("request", string(httpRequest)),
                        zap.String("stack", string(debug.Stack())),
                    )
                } else {
                    logger.Error("[Recovery from panic]",
                        zap.Any("error", err),
                        zap.String("request", string(httpRequest)),
                    )
                }
                c.AbortWithStatus(http.StatusInternalServerError)
            }
        }()
        c.Next()
    }
}

package logger

import (
    "gin_zap_demo/config"
    "net"
    "net/http"
    "net/http/httputil"
    "os"
    "runtime/debug"
    "strings"
    "time"

    "github.com/gin-gonic/gin"
    "github.com/natefinch/lumberjack"
    "go.uber.org/zap"
    "go.uber.org/zap/zapcore"
)

var lg *zap.Logger

// InitLogger 初始化Logger
func InitLogger(cfg *config.LogConfig) (err error) {
    writeSyncer := getLogWriter(cfg.Filename, cfg.MaxSize, cfg.MaxBackups, cfg.MaxAge)
    encoder := getEncoder()
    var l = new(zapcore.Level)
    err = l.UnmarshalText([]byte(cfg.Level))
    if err != nil {
        return
    }
    core := zapcore.NewCore(encoder, writeSyncer, l)

    lg = zap.New(core, zap.AddCaller())
    zap.ReplaceGlobals(lg) // 替換zap包中全局的logger實例，后續(xù)在其他包中只需使用zap.L()調(diào)用即可
    return
}

func getEncoder() zapcore.Encoder {
    encoderConfig := zap.NewProductionEncoderConfig()
    encoderConfig.EncodeTime = zapcore.ISO8601TimeEncoder
    encoderConfig.TimeKey = "time"
    encoderConfig.EncodeLevel = zapcore.CapitalLevelEncoder
    encoderConfig.EncodeDuration = zapcore.SecondsDurationEncoder
    encoderConfig.EncodeCaller = zapcore.ShortCallerEncoder
    return zapcore.NewJSONEncoder(encoderConfig)
}

func getLogWriter(filename string, maxSize, maxBackup, maxAge int) zapcore.WriteSyncer {
    lumberJackLogger := &lumberjack.Logger{
        Filename:   filename,
        MaxSize:    maxSize,
        MaxBackups: maxBackup,
        MaxAge:     maxAge,
    }
    return zapcore.AddSync(lumberJackLogger)
}

// GinLogger 接收gin框架默認的日志
func GinLogger() gin.HandlerFunc {
    return func(c *gin.Context) {
        start := time.Now()
        path := c.Request.URL.Path
        query := c.Request.URL.RawQuery
        c.Next()

        cost := time.Since(start)
        lg.Info(path,
            zap.Int("status", c.Writer.Status()),
            zap.String("method", c.Request.Method),
            zap.String("path", path),
            zap.String("query", query),
            zap.String("ip", c.ClientIP()),
            zap.String("user-agent", c.Request.UserAgent()),
            zap.String("errors", c.Errors.ByType(gin.ErrorTypePrivate).String()),
            zap.Duration("cost", cost),
        )
    }
}

// GinRecovery recover掉項目可能出現(xiàn)的panic，并使用zap記錄相關(guān)日志
func GinRecovery(stack bool) gin.HandlerFunc {
    return func(c *gin.Context) {
        defer func() {
            if err := recover(); err != nil {
                // Check for a broken connection, as it is not really a
                // condition that warrants a panic stack trace.
                var brokenPipe bool
                if ne, ok := err.(*net.OpError); ok {
                    if se, ok := ne.Err.(*os.SyscallError); ok {
                        if strings.Contains(strings.ToLower(se.Error()), "broken pipe") || strings.Contains(strings.ToLower(se.Error()), "connection reset by peer") {
                            brokenPipe = true
                        }
                    }
                }

                httpRequest, _ := httputil.DumpRequest(c.Request, false)
                if brokenPipe {
                    lg.Error(c.Request.URL.Path,
                        zap.Any("error", err),
                        zap.String("request", string(httpRequest)),
                    )
                    // If the connection is dead, we can't write a status to it.
                    c.Error(err.(error)) // nolint: errcheck
                    c.Abort()
                    return
                }

                if stack {
                    lg.Error("[Recovery from panic]",
                        zap.Any("error", err),
                        zap.String("request", string(httpRequest)),
                        zap.String("stack", string(debug.Stack())),
                    )
                } else {
                    lg.Error("[Recovery from panic]",
                        zap.Any("error", err),
                        zap.String("request", string(httpRequest)),
                    )
                }
                c.AbortWithStatus(http.StatusInternalServerError)
            }
        }()
        c.Next()
    }
}

type LogConfig struct {
    Level string `json:"level"`
    Filename string `json:"filename"`
    MaxSize int `json:"maxsize"`
    MaxAge int `json:"max_age"`
    MaxBackups int `json:"max_backups"`
}

package main

import (
    "fmt"
    "gin_zap_demo/config"
    "gin_zap_demo/logger"
    "net/http"
    "os"

    "go.uber.org/zap"

    "github.com/gin-gonic/gin"
)

func main() {
    // load config from config.json
    if len(os.Args) < 1 {
        return
    }

    if err := config.Init(os.Args[1]); err != nil {
        panic(err)
    }
    // init logger
    if err := logger.InitLogger(config.Conf.LogConfig); err != nil {
        fmt.Printf("init logger failed, err:%v\n", err)
        return
    }

    gin.SetMode(config.Conf.Mode)

    r := gin.Default()
    // 注冊zap相關(guān)中間件
    r.Use(logger.GinLogger(), logger.GinRecovery(true))

    r.GET("/hello", func(c *gin.Context) {
        // 假設你有一些數(shù)據(jù)需要記錄到日志中
        var (
            name = "itxiaoma"
            age  = 18
        )
        // 記錄日志并使用zap.Xxx(key, val)記錄相關(guān)字段
        zap.L().Debug("this is hello func", zap.String("user", name), zap.Int("age", age))

        c.String(http.StatusOK, "hello itxiaoma!")
    })

    addr := fmt.Sprintf(":%v", config.Conf.Port)
    r.Run(addr)
}