发布于 2018-01-28 20:53:31 | 83 次阅读 | 评论: 0 | 来源: 网友投递

这里有新鲜出炉的Javascript教程,程序狗速度看过来!

JavaScript客户端脚本语言

Javascript 是一种由Netscape的LiveScript发展而来的原型化继承的基于对象的动态类型的区分大小写的客户端脚本语言,主要目的是为了解决服务器端语言,比如Perl,遗留的速度问题,为客户提供更流畅的浏览效果。


这篇文章主要介绍了详解Javascript判断Crontab表达式是否合法的相关资料,需要的朋友可以参考下

Javascript判断Crontab表达式是否合法

这段时间在做Quartz任务调度,使用的Crontab表达式实现的。Crontab由前端页面输入,作为参数穿入后台。
虽然Quartz具有校验Crontab表达式的方法,如下:


boolean cronExpressionFlag = CronExpression.isValidExpression(crontab);

但是我一直想在前端直接验证,即不需要通过异步的方式向后台获取验证结果,找了好久,发现没有现成的框架可以使用,于是自己根据网上搜索到的资料,写了这个js脚本。

这个脚本目前对日和星期的判断还有点小问题,不过不影响使用。

以后如果有时间,继续完善这个脚本,废话不多说了,上代码:


 function cronValidate() {
    var cron = $("#cron").val();
    var result = CronExpressionValidator.validateCronExpression(cron);
    if(result == true){
      alert("格式正确"); 
    }
    else{
      alert("格式错误");
    }
    return CronExpressionValidator.validateCronExpression(cron); 
  } 
  function CronExpressionValidator() { 
  } 

  CronExpressionValidator.validateCronExpression = function(value) { 
    var results = true; 
    if (value == null || value.length == 0) { 
      return false; 
    } 

    // split and test length 
    var expressionArray = value.split(" "); 
    var len = expressionArray.length; 

    if ((len != 6) && (len != 7)) { 
      return false; 
    } 

    // check only one question mark 
    var match = value.match(/\?/g); 
    if (match != null && match.length > 1) { 
      return false; 
    } 

    // check only one question mark 
    var dayOfTheMonthWildcard = ""; 

    // if appropriate length test parts 
    // [0] Seconds 0-59 , - * / 
    if (CronExpressionValidator.isNotWildCard(expressionArray[0], /[\*]/gi)) { 
      if (!CronExpressionValidator.segmentValidator("([0-9\\\\,-\\/])", expressionArray[0], [0, 59], "seconds")) { 
        return false; 
      } 
    } 

    // [1] Minutes 0-59 , - * / 
    if (CronExpressionValidator.isNotWildCard(expressionArray[1], /[\*]/gi)) { 
      if (!CronExpressionValidator.segmentValidator("([0-9\\\\,-\\/])", expressionArray[1], [0, 59], "minutes")) { 
        return false; 
      } 
    } 

    // [2] Hours 0-23 , - * / 
    if (CronExpressionValidator.isNotWildCard(expressionArray[2], /[\*]/gi)) { 
      if (!CronExpressionValidator.segmentValidator("([0-9\\\\,-\\/])", expressionArray[2], [0, 23], "hours")) { 
        return false; 
      } 
    } 

    // [3] Day of month 1-31 , - * ? / L W C 
    if (CronExpressionValidator.isNotWildCard(expressionArray[3], /[\*\?]/gi)) { 
      if (!CronExpressionValidator.segmentValidator("([0-9LWC\\\\,-\\/])", expressionArray[3], [1, 31], "days of the month")) { 
        return false; 
      } 
    } else { 
      dayOfTheMonthWildcard = expressionArray[3]; 
    } 

    // [4] Month 1-12 or JAN-DEC , - * / 
    if (CronExpressionValidator.isNotWildCard(expressionArray[4], /[\*]/gi)) { 
      expressionArray[4] = CronExpressionValidator.convertMonthsToInteger(expressionArray[4]); 
      if (!CronExpressionValidator.segmentValidator("([0-9\\\\,-\\/])", expressionArray[4], [1, 12], "months")) { 
        return false; 
      } 
    } 

    // [5] Day of week 1-7 or SUN-SAT , - * ? / L C # 
    if (CronExpressionValidator.isNotWildCard(expressionArray[5], /[\*\?]/gi)) { 
      expressionArray[5] = CronExpressionValidator.convertDaysToInteger(expressionArray[5]); 
      if (!CronExpressionValidator.segmentValidator("([0-9LC#\\\\,-\\/])", expressionArray[5], [1, 7], "days of the week")) { 
        return false; 
      } 
    } else { 
      if (dayOfTheMonthWildcard == String(expressionArray[5])) { 
        return false; 
      } 
    } 

    // [6] Year empty or 1970-2099 , - * / 
    if (len == 7) { 
      if (CronExpressionValidator.isNotWildCard(expressionArray[6], /[\*]/gi)) { 
        if (!CronExpressionValidator.segmentValidator("([0-9\\\\,-\\/])", expressionArray[6], [1970, 2099], "years")) { 
          return false; 
        } 
      } 
    } 
    return true; 
  } 

  // ---------------------------------- 
  // isNotWildcard 静态方法; 
  // ---------------------------------- 
  CronExpressionValidator.isNotWildCard = function(value, expression) { 
    var match = value.match(expression); 
    return (match == null || match.length == 0) ? true : false; 
  } 

  // ---------------------------------- 
  // convertDaysToInteger 静态方法; 
  // ---------------------------------- 
  CronExpressionValidator.convertDaysToInteger = function(value) { 
    var v = value; 
    v = v.replace(/SUN/gi, "1"); 
    v = v.replace(/MON/gi, "2"); 
    v = v.replace(/TUE/gi, "3"); 
    v = v.replace(/WED/gi, "4"); 
    v = v.replace(/THU/gi, "5"); 
    v = v.replace(/FRI/gi, "6"); 
    v = v.replace(/SAT/gi, "7"); 
    return v; 
  } 

  // ---------------------------------- 
  // convertMonthsToInteger 静态方法; 
  // ---------------------------------- 
  CronExpressionValidator.convertMonthsToInteger = function(value) { 
    var v = value; 
    v = v.replace(/JAN/gi, "1"); 
    v = v.replace(/FEB/gi, "2"); 
    v = v.replace(/MAR/gi, "3"); 
    v = v.replace(/APR/gi, "4"); 
    v = v.replace(/MAY/gi, "5"); 
    v = v.replace(/JUN/gi, "6"); 
    v = v.replace(/JUL/gi, "7"); 
    v = v.replace(/AUG/gi, "8"); 
    v = v.replace(/SEP/gi, "9"); 
    v = v.replace(/OCT/gi, "10"); 
    v = v.replace(/NOV/gi, "11"); 
    v = v.replace(/DEC/gi, "12"); 
    return v; 
  } 

  // ---------------------------------- 
  // segmentValidator 静态方法; 
  // ---------------------------------- 
  CronExpressionValidator.segmentValidator = function(expression, value, range, segmentName) { 
    var v = value; 
    var numbers = new Array(); 

    // first, check for any improper segments 
    var reg = new RegExp(expression, "gi"); 
    if (!reg.test(v)) {  
      return false; 
    } 

    // check duplicate types 
    // check only one L 
    var dupMatch = value.match(/L/gi); 
    if (dupMatch != null && dupMatch.length > 1) { 
      return false; 
    } 

    // look through the segments 
    // break up segments on ',' 
    // check for special cases L,W,C,/,#,- 
    var split = v.split(","); 
    var i = -1; 
    var l = split.length; 
    var match; 

    while (++i < l) { 
      // set vars 
      var checkSegment = split[i]; 
      var n; 
      var pattern = /(\w*)/; 
      match = pattern.exec(checkSegment); 

      // if just number 
      pattern = /(\w*)\-?\d+(\w*)/; 
      match = pattern.exec(checkSegment); 

      if (match 
          && match[0] == checkSegment 
          && checkSegment.indexOf("L") == -1 
          && checkSegment.indexOf("l") == -1 
          && checkSegment.indexOf("C") == -1 
          && checkSegment.indexOf("c") == -1 
          && checkSegment.indexOf("W") == -1 
          && checkSegment.indexOf("w") == -1 
          && checkSegment.indexOf("/") == -1 
          && (checkSegment.indexOf("-") == -1 || checkSegment 
              .indexOf("-") == 0) && checkSegment.indexOf("#") == -1) { 
        n = match[0]; 

        if (n && !(isNaN(n))) 
          numbers.push(n); 
        else if (match[0] == "0") 
          numbers.push(n); 
        continue; 
      } 
  // includes L, C, or w 
      pattern = /(\w*)L|C|W(\w*)/i; 
      match = pattern.exec(checkSegment); 

      if (match 
          && match[0] != "" 
          && (checkSegment.indexOf("L") > -1 
              || checkSegment.indexOf("l") > -1 
              || checkSegment.indexOf("C") > -1 
              || checkSegment.indexOf("c") > -1 
              || checkSegment.indexOf("W") > -1 || checkSegment 
              .indexOf("w") > -1)) { 

        // check just l or L 
        if (checkSegment == "L" || checkSegment == "l") 
          continue; 
        pattern = /(\w*)\d+(l|c|w)?(\w*)/i; 
        match = pattern.exec(checkSegment); 

        // if something before or after 
        if (!match || match[0] != checkSegment) {  
          continue; 
        } 

        // get the number 
        var numCheck = match[0]; 
        numCheck = numCheck.replace(/(l|c|w)/ig, ""); 

        n = Number(numCheck); 

        if (n && !(isNaN(n))) 
          numbers.push(n); 
        else if (match[0] == "0") 
          numbers.push(n); 
        continue; 
      } 

      var numberSplit; 

      // includes / 
      if (checkSegment.indexOf("/") > -1) { 
        // take first # 
        numberSplit = checkSegment.split("/"); 

        if (numberSplit.length != 2) {  
          continue; 
        } else { 
          n = numberSplit[0]; 

          if (n && !(isNaN(n))) 
            numbers.push(n); 
          else if (numberSplit[0] == "0") 
            numbers.push(n); 
          continue; 
        } 
      } 

      // includes # 
      if (checkSegment.indexOf("#") > -1) { 
        // take first # 
        numberSplit = checkSegment.split("#"); 

        if (numberSplit.length != 2) {  
          continue; 
        } else { 
          n = numberSplit[0]; 

          if (n && !(isNaN(n))) 
            numbers.push(n); 
          else if (numberSplit[0] == "0") 
            numbers.push(n); 
          continue; 
        } 
      } 

  // includes - 
      if (checkSegment.indexOf("-") > 0) { 
        // take both # 
        numberSplit = checkSegment.split("-"); 

        if (numberSplit.length != 2) {  
          continue; 
        } else if (Number(numberSplit[0]) > Number(numberSplit[1])) { 
          continue; 
        } else { 
          n = numberSplit[0]; 

          if (n && !(isNaN(n))) 
            numbers.push(n); 
          else if (numberSplit[0] == "0") 
            numbers.push(n); 
          n = numberSplit[1]; 

          if (n && !(isNaN(n))) 
            numbers.push(n); 
          else if (numberSplit[1] == "0") 
            numbers.push(n); 
          continue; 
        } 
      } 

    } 
    // lastly, check that all the found numbers are in range 
    i = -1; 
    l = numbers.length; 

    if (l == 0) 
      return false; 

    while (++i < l) { 
      // alert(numbers[i]); 
      if (numbers[i] < range[0] || numbers[i] > range[1]) { 
        return false; 
      } 
    } 
    return true; 
  } 

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