Golang 解析 time.Duration

Question

我想解析time.Duration. 持续时间是"PT15M"（字符串/字节），并希望将其转换为有效的time.Duration.如果这是一time.Time件事，我会使用：t, err := time.Parse(time.RFC3339Nano, "2013-06-05T14:10:43.678Z")但这不存在（ParseDuration只需要一个参数）：d, err := time.ParseDuration(time.RFC3339Nano, "PT15M")如何解析此ISO 8601 持续时间？

Answer 1

它并不完全是“开箱即用”，而是正则表达式可以完成这项工作：

package main

import "fmt"

import "regexp"

import "strconv"

import "time"

func main() {

    fmt.Println(ParseDuration("PT15M"))

    fmt.Println(ParseDuration("P12Y4MT15M"))

}

func ParseDuration(str string) time.Duration {

    durationRegex := regexp.MustCompile(`P(?P<years>\d+Y)?(?P<months>\d+M)?(?P<days>\d+D)?T?(?P<hours>\d+H)?(?P<minutes>\d+M)?(?P<seconds>\d+S)?`)

    matches := durationRegex.FindStringSubmatch(str)

    years := ParseInt64(matches[1])

    months := ParseInt64(matches[2])

    days := ParseInt64(matches[3])

    hours := ParseInt64(matches[4])

    minutes := ParseInt64(matches[5])

    seconds := ParseInt64(matches[6])

    hour := int64(time.Hour)

    minute := int64(time.Minute)

    second := int64(time.Second)

    return time.Duration(years*24*365*hour + months*30*24*hour + days*24*hour + hours*hour + minutes*minute + seconds*second)

}

func ParseInt64(value string) int64 {

    if len(value) == 0 {

        return 0

    }

    parsed, err := strconv.Atoi(value[:len(value)-1])

    if err != nil {

        return 0

    }

    return int64(parsed)

}

Answer 2

这是处理分数时间单位的代码，如PT3.001S.

var durationRegex = regexp.MustCompile(`P([\d\.]+Y)?([\d\.]+M)?([\d\.]+D)?T?([\d\.]+H)?([\d\.]+M)?([\d\.]+?S)?`)

// ParseDuration converts a ISO8601 duration into a time.Duration

func ParseDuration(str string) time.Duration {

   matches := durationRegex.FindStringSubmatch(str)

   years := parseDurationPart(matches[1], time.Hour*24*365)

   months := parseDurationPart(matches[2], time.Hour*24*30)

   days := parseDurationPart(matches[3], time.Hour*24)

   hours := parseDurationPart(matches[4], time.Hour)

   minutes := parseDurationPart(matches[5], time.Second*60)

   seconds := parseDurationPart(matches[6], time.Second)

   return time.Duration(years + months + days + hours + minutes + seconds)

}

func parseDurationPart(value string, unit time.Duration) time.Duration {

   if len(value) != 0 {

       if parsed, err := strconv.ParseFloat(value[:len(value)-1], 64); err == nil {

           return time.Duration(float64(unit) * parsed)

       }

   }

   return 0

}