Golang Web服务器突然停止运行的原因及解决方法

正如我所说，无论原帖作者使用什么进行日志记录

服务器突然停止通常由以下几个原因导致：

1. panic未恢复

最常见的原因是未处理的panic。添加recovery中间件：

func recoveryMiddleware(next http.HandlerFunc) http.HandlerFunc {
    return func(w http.ResponseWriter, r *http.Request) {
        defer func() {
            if err := recover(); err != nil {
                fmt.Printf("Panic recovered: %v\n", err)
                http.Error(w, "Internal Server Error", http.StatusInternalServerError)
            }
        }()
        next(w, r)
    }
}

func main() {
    http.HandleFunc("/", recoveryMiddleware(page))
    http.ListenAndServe(":5050", nil)
}

2. 模板执行错误

模板执行失败可能导致panic：

func page(w http.ResponseWriter, r *http.Request) {
    path := strings.Trim(r.URL.Path, "/")
    fmt.Println(path)
    
    switch path {
    case "favicon.ico":
        http.ServeFile(w, r, "/static/favicon.ico")
    case "norec":
        if err := tpl.ExecuteTemplate(w, "norec.html", ""); err != nil {
            fmt.Printf("Template error: %v\n", err)
            http.Error(w, "Internal Server Error", http.StatusInternalServerError)
        }
    default:
        if err := tpl.ExecuteTemplate(w, "home.html", ""); err != nil {
            fmt.Printf("Template error: %v\n", err)
            http.Error(w, "Internal Server Error", http.StatusInternalServerError)
        }
    }
}

3. 文件路径问题

静态文件路径可能导致panic：

func init() {
    var err error
    tpl, err = template.ParseGlob("public/templates/*.html")
    if err != nil {
        panic(fmt.Sprintf("Template parsing error: %v", err))
    }
    
    // 检查目录是否存在
    dirs := []string{"./public/img", "./public/css", "./public/icn", "./public/js"}
    for _, dir := range dirs {
        if _, err := os.Stat(dir); os.IsNotExist(err) {
            fmt.Printf("Warning: directory %s does not exist\n", dir)
        }
    }
    
    http.Handle("/img/", http.StripPrefix("/img/", http.FileServer(http.Dir("./public/img"))))
    http.Handle("/css/", http.StripPrefix("/css/", http.FileServer(http.Dir("./public/css"))))
    http.Handle("/icn/", http.StripPrefix("/icn/", http.FileServer(http.Dir("./public/icn"))))
    http.Handle("/js/", http.StripPrefix("/js/", http.FileServer(http.Dir("./public/js"))))
}

4. 添加详细日志

启用详细日志记录：

func loggingMiddleware(next http.HandlerFunc) http.HandlerFunc {
    return func(w http.ResponseWriter, r *http.Request) {
        start := time.Now()
        fmt.Printf("[%s] %s %s\n", r.Method, r.URL.Path, r.RemoteAddr)
        
        rw := &responseWriter{ResponseWriter: w, statusCode: http.StatusOK}
        next(rw, r)
        
        fmt.Printf("[%d] %s %s completed in %v\n", 
            rw.statusCode, r.Method, r.URL.Path, time.Since(start))
    }
}

type responseWriter struct {
    http.ResponseWriter
    statusCode int
}

func (rw *responseWriter) WriteHeader(code int) {
    rw.statusCode = code
    rw.ResponseWriter.WriteHeader(code)
}

func main() {
    http.HandleFunc("/", loggingMiddleware(recoveryMiddleware(page)))
    
    fmt.Println("Server starting on :5050")
    if err := http.ListenAndServe(":5050", nil); err != nil {
        fmt.Printf("Server error: %v\n", err)
    }
}

5. 检查系统资源

添加资源监控：

func monitorResources() {
    go func() {
        for {
            var m runtime.MemStats
            runtime.ReadMemStats(&m)
            fmt.Printf("Alloc = %v MiB, TotalAlloc = %v MiB, Sys = %v MiB, NumGC = %v\n",
                m.Alloc/1024/1024, m.TotalAlloc/1024/1024, m.Sys/1024/1024, m.NumGC)
            time.Sleep(30 * time.Second)
        }
    }()
}

func main() {
    monitorResources()
    http.HandleFunc("/", loggingMiddleware(recoveryMiddleware(page)))
    
    fmt.Println("Server starting on :5050")
    if err := http.ListenAndServe(":5050", nil); err != nil {
        fmt.Printf("Server error: %v\n", err)
    }
}

6. favicon.ico路径问题

修正favicon处理：

func page(w http.ResponseWriter, r *http.Request) {
    path := strings.Trim(r.URL.Path, "/")
    fmt.Println("Request path:", path)
    
    switch path {
    case "favicon.ico":
        // 使用相对路径或绝对路径
        faviconPath := "./public/static/favicon.ico"
        if _, err := os.Stat(faviconPath); os.IsNotExist(err) {
            http.NotFound(w, r)
            return
        }
        http.ServeFile(w, r, faviconPath)
    case "norec":
        if err := tpl.ExecuteTemplate(w, "norec.html", ""); err != nil {
            fmt.Printf("Template error: %v\n", err)
            http.Error(w, "Internal Server Error", http.StatusInternalServerError)
        }
    default:
        if err := tpl.ExecuteTemplate(w, "home.html", ""); err != nil {
            fmt.Printf("Template error: %v\n", err)
            http.Error(w, "Internal Server Error", http.StatusInternalServerError)
        }
    }
}

这些修改会帮助捕获错误并记录服务器状态，从而确定停止的具体原因。