Cron 表达式的JavaScript验证代码

亦凉 2022-06-17 11:00 554阅读 0赞

根据CronExpressionValidator类的思路，改写了一个Cron Expression Validator,这样在做验证就比较方便了。

/**
         * Validates a cron expression.
         *
         * @param cronExpression The expression to validate
         * @return True is expression is valid
         */
        function cronValidate(cronExpression ){
            //alert("校验函数的开始！");
            var cronParams = cronExpression.split(" ");
    
            if (cronParams.length < 6 || cronParams.length > 7) {
                return false;
            }
    
            //CronTrigger cronTrigger = new CronTrigger();
            //cronTrigger.setCronExpression( cronExpression );
    
            if (cronParams[3] == "?" || cronParams[5]=="?") {
                //Check seconds param
                if (!checkSecondsField(cronParams[0])) {
                    return false;
                }
    
                //Check minutes param
                if (!checkMinutesField(cronParams[1])) {
                    return false;
                }
    
                //Check hours param
                if (!checkHoursField(cronParams[2])) {
                    return false;
                }
    
                //Check day-of-month param
                if (!checkDayOfMonthField(cronParams[3])) {
                    return false;
                }
    
                //Check months param
                if (!checkMonthsField(cronParams[4])) {
                    return false;
                }
    
                //Check day-of-week param
                if (!checkDayOfWeekField(cronParams[5])) {
                    return false;
                }
    
                //Check year param
                if (cronParams.length == 7) {
                    if (!checkYearField(cronParams[6])) {
                        return false;
                    }
                }
    
                return true;
            } else {
                return false;
            }
        }
    
        function checkSecondsField(secondsField) {
            return checkField(secondsField, 0, 59);
        }
    
    
        function checkField(secondsField, minimal, maximal) {
            if (secondsField.indexOf("-") > -1 ) {
                var startValue = secondsField.substring(0, secondsField.indexOf( "-" ));
                var endValue = secondsField.substring(secondsField.indexOf( "-" ) + 1);
    
                if (!(checkIntValue(startValue, minimal, maximal, true) && checkIntValue(endValue, minimal, maximal, true))) {
                    return false;
                }
                try {
                    var startVal = parseInt(startValue, 10);
                    var endVal = parseInt(endValue, 10);
    
                    return endVal > startVal;
                } catch (e) {
                    return false;
                }
            } else if (secondsField.indexOf(",") > -1) {
                return checkListField(secondsField, minimal, maximal);
            } else if (secondsField.indexOf( "/" ) > -1) {
                return checkIncrementField( secondsField, minimal, maximal );
            } else if (secondsField.indexOf( "*" ) != -1) {
                return true;
            } else {
                return checkIntValue(secondsField, minimal, maximal);
            }
        }
    
        function checkIntValue(value, minimal, maximal, checkExtremity) {
            try {
                var val = parseInt(value, 10);
                //判断是否为整数
                if (value == val) {
                    if (checkExtremity) {
                        if (val < minimal || val > maximal) {
                            return false;
                        }
                    }
    
                    return true;
                }
    
                return false;
            } catch (e) {
                return false;
            }
        }
    
        function checkMinutesField(minutesField) {
            return checkField(minutesField, 0, 59);
        }
    
        function checkHoursField(hoursField) {
            return checkField(hoursField, 0, 23);
        }
    
        function checkDayOfMonthField(dayOfMonthField) {
            if (dayOfMonthField == "?") {
                return true;
            }
    
            if (dayOfMonthField.indexOf("L") >= 0) {
                return checkFieldWithLetter(dayOfMonthField, "L", 1, 7, -1, -1);
            } else if ( dayOfMonthField.indexOf("W") >= 0) {
                return checkFieldWithLetter(dayOfMonthField, "W", 1, 31, -1, -1);
            } else if (dayOfMonthField.indexOf("C") >= 0) {
                return checkFieldWithLetter(dayOfMonthField, "C", 1, 31, -1, -1);
            } else {
                return checkField( dayOfMonthField, 1, 31 );
            }
        }
    
    
        function checkMonthsField(monthsField) {
    /*        monthsField = StringUtils.replace( monthsField, "JAN", "1" );
            monthsField = StringUtils.replace( monthsField, "FEB", "2" );
            monthsField = StringUtils.replace( monthsField, "MAR", "3" );
            monthsField = StringUtils.replace( monthsField, "APR", "4" );
            monthsField = StringUtils.replace( monthsField, "MAY", "5" );
            monthsField = StringUtils.replace( monthsField, "JUN", "6" );
            monthsField = StringUtils.replace( monthsField, "JUL", "7" );
            monthsField = StringUtils.replace( monthsField, "AUG", "8" );
            monthsField = StringUtils.replace( monthsField, "SEP", "9" );
            monthsField = StringUtils.replace( monthsField, "OCT", "10" );
            monthsField = StringUtils.replace( monthsField, "NOV", "11" );
            monthsField = StringUtils.replace( monthsField, "DEC", "12" );*/
    
            monthsField.replace("JAN", "1");
            monthsField.replace("FEB", "2");
            monthsField.replace("MAR", "3");
            monthsField.replace("APR", "4");
            monthsField.replace("MAY", "5");
            monthsField.replace("JUN", "6");
            monthsField.replace("JUL", "7");
            monthsField.replace("AUG", "8");
            monthsField.replace("SEP", "9");
            monthsField.replace("OCT", "10");
            monthsField.replace("NOV", "11");
            monthsField.replace("DEC", "12");
    
            return checkField(monthsField, 1, 31);
        }
    
        function checkDayOfWeekField(dayOfWeekField) {
    /*        dayOfWeekField = StringUtils.replace( dayOfWeekField, "SUN", "1" );
            dayOfWeekField = StringUtils.replace( dayOfWeekField, "MON", "2" );
            dayOfWeekField = StringUtils.replace( dayOfWeekField, "TUE", "3" );
            dayOfWeekField = StringUtils.replace( dayOfWeekField, "WED", "4" );
            dayOfWeekField = StringUtils.replace( dayOfWeekField, "THU", "5" );
            dayOfWeekField = StringUtils.replace( dayOfWeekField, "FRI", "6" );
            dayOfWeekField = StringUtils.replace( dayOfWeekField, "SAT", "7" );*/
    
            dayOfWeekField.replace("SUN", "1" );
            dayOfWeekField.replace("MON", "2" );
            dayOfWeekField.replace("TUE", "3" );
            dayOfWeekField.replace("WED", "4" );
            dayOfWeekField.replace("THU", "5" );
            dayOfWeekField.replace("FRI", "6" );
            dayOfWeekField.replace("SAT", "7" );        
    
            if (dayOfWeekField == "?") {
                return true;
            }
    
            if (dayOfWeekField.indexOf("L") >= 0) {
                return checkFieldWithLetter(dayOfWeekField, "L", 1, 7, -1, -1);
            } else if (dayOfWeekField.indexOf("C") >= 0) {
                return checkFieldWithLetter(dayOfWeekField, "C", 1, 7, -1, -1);
            } else if (dayOfWeekField.indexOf("#") >= 0) {
                return checkFieldWithLetter(dayOfWeekField, "#", 1, 7, 1, 5);
            } else {
                return checkField(dayOfWeekField, 1, 7);
            }
        }
    
        function checkYearField(yearField) {
            return checkField(yearField, 1970, 2099);
        }
    
    
        function checkFieldWithLetter(value, letter, minimalBefore, maximalBefore,
                                              minimalAfter, maximalAfter) {
            var canBeAlone = false;
            var canHaveIntBefore = false;
            var canHaveIntAfter = false;
            var mustHaveIntBefore = false;
            var mustHaveIntAfter = false;
    
            if (letter == "L") {
                canBeAlone = true;
                canHaveIntBefore = true;
                canHaveIntAfter = false;
                mustHaveIntBefore = false;
                mustHaveIntAfter = false;
            }
            if (letter == "W" || letter == "C") {
                canBeAlone = false;
                canHaveIntBefore = true;
                canHaveIntAfter = false;
                mustHaveIntBefore = true;
                mustHaveIntAfter = false;
            }
            if (letter == "#") {
                canBeAlone = false;
                canHaveIntBefore = true;
                canHaveIntAfter = true;
                mustHaveIntBefore = true;
                mustHaveIntAfter = true;
            }
    
            var beforeLetter = "";
            var afterLetter = "";
    
            if (value.indexOf(letter) >= 0 ) {
                beforeLetter = value.substring( 0, value.indexOf(letter));
            }
    
            if (!value.endsWith(letter)) {
                afterLetter = value.substring( value.indexOf( letter ) + 1 );
            }
    
            if (value.indexOf(letter) >= 0) {
                if (letter == value) {
                    return canBeAlone;
                }
    
                if (canHaveIntBefore) {
                    if (mustHaveIntBefore && beforeLetter.length == 0) {
                        return false;
                    }
    
                    if (!checkIntValue(beforeLetter, minimalBefore, maximalBefore, true)){
                        return false;
                    }
                } else {
                    if (beforeLetter.length > 0 ) {
                        return false;
                    }
                }
    
                if (canHaveIntAfter) {
                    if ( mustHaveIntAfter && afterLetter.length == 0 ) {
                        return false;
                    }
    
                    if (!checkIntValue(afterLetter, minimalAfter, maximalAfter, true)) {
                        return false;
                    }
                } else {
                    if (afterLetter.length > 0) {
                        return false;
                    }
                }
            }
    
            return true;
        }
    
    /*    function checkIntValue(value, minimal, maximal) {
            return checkIntValue(value, minimal, maximal, true);
        } */
    
        function checkIncrementField(value, minimal, maximal) {
            var start = value.substring(0, value.indexOf("/"));
    
            var increment = value.substring(value.indexOf("/") + 1);
    
            if (!("*" == start)) {
                return checkIntValue(start, minimal, maximal, true) && checkIntValue(increment, minimal, maximal, false);
            } else {
                return checkIntValue(increment, minimal, maximal, true);
            }
        }
    
    
    
        function checkListField(value, minimal, maximal ) {
            var st = value.split(",");
    
            var values = new Array(st.length);
    
            for(var j = 0; j < st.length; j++) {
                values[j] = st[j];
            }
    
            var previousValue = -1;
    
            for (var i= 0; i < values.length; i++) {
                var currentValue = values[i];
    
                if (!checkIntValue(currentValue, minimal, maximal, true)) {
                    return false;
                }
    
                try {
                    var val = parseInt(currentValue, 10);
    
                    if (val <= previousValue) {
                        return false;
                    } else {
                        previousValue = val;
                    }
                } catch (e) {
                    // we have always an int
                }
            }
    
            return true;
        }