日期区间正则表达式生成模块

def genRegexp(start:String,end:String): String = {
        //s:开始e：结束y：年m：月d：日o：个位t：十位
        //sy:开始年em：结束月，其他变量命名规则相同
        val sy = start.substring(0, 4)
        val sm = start.substring(4, 6)
        val sd = start.substring(6, 8)
        val ey = end.substring(0, 4)
        val em = end.substring(4, 6)
        val ed = end.substring(6, 8)
        val sdo = sd.substring(1, 2)
        val sdt = sd.substring(0, 1)
        val smo = sm.substring(1, 2)
        val smt = sm.substring(0, 1)
        val syo = sy.substring(3, 4)
        val syt = sy.substring(2, 3)
        val edo = ed.substring(1, 2)
        val edt = ed.substring(0, 1)
        val emo = em.substring(1, 2)
        val emt = em.substring(0, 1)
        val eyo = ey.substring(3, 4)
        val eyt = ey.substring(2, 3)
        var PAL = ""
        var PAR = ""
        var PA = ""
        var PB = ""
        var PC = ""
        var PCL = ""
        var PCR = ""
        var pattern = ""
        var PL = ""
        var PR = ""
        var PRT = ""
        if (sy == ey) {
            if (sm == em) {
                if (sdt == edt) {
                    pattern = "(^%s%s%s[%s-%s]$)".format(sy, sm, sdt, sdo, edo)
                }
                else {
                    if (sdt.toInt + 1 == edt.toInt) {
                        pattern = "(^%s%s((%s[%s-9])|(%s[0-%s]))$)".format(sy, sm, sdt, sdo, edt, edo)
                    }
                    else {
                        pattern = "(^%s%s((%s[%s-9])|(%s[0-%s])|([%d-%d]\\d))$)".format(sy, sm, sdt, sdo,
                            edt, edo, sdt.toInt + 1, edt.toInt - 1)
                    }
                }
            }
            else {
                if (sdt == "3") {
                    PL = "(%s3[%s-9])".format(sm, sdo)
                }
                else {
                    PL = "(%s((%s[%s-9])|([%d-3]\\d)))".format(sm, sdt, sdo, sdt.toInt + 1)
                }
                if (edt == "0") {
                    PR = "(%s0[0-%s])".format(em, edo)
                }
                else {
                    PR = "(%s(([0-%d]\\d)|(%s[0-%s])))".format(em, edt.toInt - 1, edt, edo)
                }
                PRT = "(pass)"
                if (sm.toInt + 1 != em.toInt) {
                    val sma = sm.toInt + 1
                    val emr = em.toInt - 1
                    if (sma < 10) {
                        if (emr < 10) {
                            PRT = "(0[%d-%d]\\d{2})".format(sma, emr)
                        }
                        else {
                            PRT = "(((0[%d-9])|(1[0-%d]))\\d{2})".format(smo.toInt + 1, emo.toInt - 1)
                        }
                    }
                    else {
                        PRT = "((1[%s-%s])\\d{2})".format((sma.toString).substring(1,2),
                            (emr.toString).substring(1,2))
                    }
                }
                pattern = "(^%s(%s|%s|%s)$)".format(sy, PL, PR, PRT)
            }
        }
        else {
            //构造PA
            if (sdt == "3") {
                PAL = "%s(%s[%s-9])".format(sm, sdt, sdo)
            }
            else {
                PAL = "(%s((%s[%s-9])|([%d-3]\\d)))".format(sm, sdt, sdo, sdt.toInt + 1)
            }
            if (sm.toInt == 12) {
                PAR = "(pass)"
            }
            else if (sm.toInt >= 9) {
                var sm2 = (sm.toInt + 1).toString
                var smo2 = sm2.substring(1,2)
                PAR = "(1[%s-2]\\d\\d)".format(smo2)
            }
            else {
                PAR = "(((0[%d-9])|(1[0-2]))\\d{2})".format(smo.toInt + 1)
            }
            PA = "(^%s(%s|%s)$)".format(sy, PAL, PAR)
            //构造PB,已知问题，结束年不可为2000
            if (sy.toInt + 1 != ey.toInt) {
                var sy2 = (sy.toInt + 1).toString
                var syt2 = sy2.substring(2,3)
                var syo2 = sy2.substring(3,4)
                var ey2 = (ey.toInt - 1).toString
                var eyt2 = ey2.substring(2,3)
                var eyo2 = ey2.substring(3,4)
                if (syt2 == eyt2) {
                    PB = "(^20%s[%s-%s]\\d{4}$)".format(syt2, syo2, eyo2)
                }
                else {
                    if (syt2.toInt + 1 != eyt2.toInt) {
                        PB = "(^20((%s[%d-9])|([%d-%d]\\d)|(%s[0-%s]))\\d{4}$)".format(syt2, syo2.toInt,
                            syt2.toInt + 1, eyt2.toInt - 1, eyt2, eyo2)
                    }
                    else {
                        PB = "(^20((%s[%d-9])|(%s[0-%s]))\\d{4}$)".format(syt2, syo2.toInt,
                            eyt2, eyo2)
                    }
                }
            }
            else {
                PB = "(pass)"
            }
            //构造PC
            if (edt == "0") {
                PCR = "(%s%s[0-%s])".format(em, edt, edo)
            }
            else {
                PCR = "(%s(([0-%d]\\d)|(%s[0-%s])))".format(em, edt.toInt - 1, edt, edo)
            }
            if (em.toInt >= 11) {
                PCL = "(((0[1-9])|(1[0-%d]))\\d{2})".format( emo.toInt - 1)
            }
            else if (em.toInt == 10) {
                PCL = "(0[1-9]\\d{2})"
            }
            else {
                PCL = "(0[0-%d]\\d{2})".format(emo.toInt - 1)
            }
            PC = "(^%s(%s|%s)$)".format(ey, PCL, PCR)
            pattern = "%s|%s|%s".format(PA, PB, PC)
        }
        pattern
    }