Golang命令模式日志实现技巧

type Command interface {
    Execute()
}

type LoggedCommand struct {
    cmd  Command
    name string
    log  *log.Logger
}

func NewLoggedCommand(cmd Command, name string, logger *log.Logger) *LoggedCommand {
    return &LoggedCommand{
        cmd:  cmd,
        name: name,
        log:  logger,
    }
}

func (lc *LoggedCommand) Execute() {
    lc.log.Printf("开始执行命令: %s", lc.name)
    lc.cmd.Execute()
    lc.log.Printf("完成执行命令: %s", lc.name)
}

type WriteFileCommand struct {
    Filename string
    Content  string
}

func (w *WriteFileCommand) Execute() {
    // 模拟写入文件
    fmt.Printf("正在写入文件 %s: %s\n", w.Filename, w.Content)
    // 实际可调用 ioutil.WriteFile 等
}

logger := log.New(os.Stdout, "[LOG] ", log.LstdFlags)
cmd := &WriteFileCommand{Filename: "test.txt", Content: "Hello"}
loggedCmd := NewLoggedCommand(cmd, "WriteFile", logger)
loggedCmd.Execute()

func (lc *LoggedCommand) Execute() {
    start := time.Now()
    lc.log.Printf("开始执行命令: %s", lc.name)
    defer func() {
        duration := time.Since(start)
        if r := recover(); r != nil {
            lc.log.Printf("命令执行失败: %s, 错误: %v, 耗时: %v", lc.name, r, duration)
            panic(r)
        } else {
            lc.log.Printf("完成执行命令: %s, 耗时: %v", lc.name, duration)
        }
    }()
    lc.cmd.Execute()
}