java - 알파벳 증가 시키기 -alphabet

개발하다 보면 알파벳 포함한 문자열을 KEY로 잡으면서 시퀀셜하게 증가 시켜야하는 경우가 있습니다.

이럴 때 사용할 수 있는 알파벳 증가 시키키 함수 입니다.

아래 함수를 쓰시면 됩니다.

  public static String nextAlphabet(String source) {
    int length = source.length();
    char lastChar = source.charAt(length - 1);
    if (lastChar == 'Z') {
      if (length == 1) {
        return source = "AA";
      }
      source = nextAlphabet(source.substring(0, length - 1));
      source += "A";
      return source;
    }
    return source.substring(0, length - 1) + String.valueOf((char) (lastChar + 1));
  }
 
  public static void main(String[] args) {
    String source = "A";
    for (int i = 1; i < 1000; i++) {
      if (i % 26 == 0) {
        System.out.println();
      }
      source = nextAlphabet(source);
      System.out.print(source + ",");
 
    }
  }

결과 화면은 아래와 같습니다.

Z까지 되면 자릿수가 늘어 납니다.

B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,
AA,AB,AC,AD,AE,AF,AG,AH,AI,AJ,AK,AL,AM,AN,AO,AP,AQ,AR,AS,AT,AU,AV,AW,AX,AY,AZ,
BA,BB,BC,BD,BE,BF,BG,BH,BI,BJ,BK,BL,BM,BN,BO,BP,BQ,BR,BS,BT,BU,BV,BW,BX,BY,BZ,
CA,CB,CC,CD,CE,CF,CG,CH,CI,CJ,CK,CL,CM,CN,CO,CP,CQ,CR,CS,CT,CU,CV,CW,CX,CY,CZ,
DA,DB,DC,DD,DE,DF,DG,DH,DI,DJ,DK,DL,DM,DN,DO,DP,DQ,DR,DS,DT,DU,DV,DW,DX,DY,DZ,
EA,EB,EC,ED,EE,EF,EG,EH,EI,EJ,EK,EL,EM,EN,EO,EP,EQ,ER,ES,ET,EU,EV,EW,EX,EY,EZ,
FA,FB,FC,FD,FE,FF,FG,FH,FI,FJ,FK,FL,FM,FN,FO,FP,FQ,FR,FS,FT,FU,FV,FW,FX,FY,FZ,
GA,GB,GC,GD,GE,GF,GG,GH,GI,GJ,GK,GL,GM,GN,GO,GP,GQ,GR,GS,GT,GU,GV,GW,GX,GY,GZ,
HA,HB,HC,HD,HE,HF,HG,HH,HI,HJ,HK,HL,HM,HN,HO,HP,HQ,HR,HS,HT,HU,HV,HW,HX,HY,HZ,
IA,IB,IC,ID,IE,IF,IG,IH,II,IJ,IK,IL,IM,IN,IO,IP,IQ,IR,IS,IT,IU,IV,IW,IX,IY,IZ,
JA,JB,JC,JD,JE,JF,JG,JH,JI,JJ,JK,JL,JM,JN,JO,JP,JQ,JR,JS,JT,JU,JV,JW,JX,JY,JZ,
KA,KB,KC,KD,KE,KF,KG,KH,KI,KJ,KK,KL,KM,KN,KO,KP,KQ,KR,KS,KT,KU,KV,KW,KX,KY,KZ,
LA,LB,LC,LD,LE,LF,LG,LH,LI,LJ,LK,LL,LM,LN,LO,LP,LQ,LR,LS,LT,LU,LV,LW,LX,LY,LZ,
MA,MB,MC,MD,ME,MF,MG,MH,MI,MJ,MK,ML,MM,MN,MO,MP,MQ,MR,MS,MT,MU,MV,MW,MX,MY,MZ,
NA,NB,NC,ND,NE,NF,NG,NH,NI,NJ,NK,NL,NM,NN,NO,NP,NQ,NR,NS,NT,NU,NV,NW,NX,NY,NZ,
OA,OB,OC,OD,OE,OF,OG,OH,OI,OJ,OK,OL,OM,ON,OO,OP,OQ,OR,OS,OT,OU,OV,OW,OX,OY,OZ,
PA,PB,PC,PD,PE,PF,PG,PH,PI,PJ,PK,PL,PM,PN,PO,PP,PQ,PR,PS,PT,PU,PV,PW,PX,PY,PZ,
QA,QB,QC,QD,QE,QF,QG,QH,QI,QJ,QK,QL,QM,QN,QO,QP,QQ,QR,QS,QT,QU,QV,QW,QX,QY,QZ,
RA,RB,RC,RD,RE,RF,RG,RH,RI,RJ,RK,RL,RM,RN,RO,RP,RQ,RR,RS,RT,RU,RV,RW,RX,RY,RZ,
SA,SB,SC,SD,SE,SF,SG,SH,SI,SJ,SK,SL,SM,SN,SO,SP,SQ,SR,SS,ST,SU,SV,SW,SX,SY,SZ,
TA,TB,TC,TD,TE,TF,TG,TH,TI,TJ,TK,TL,TM,TN,TO,TP,TQ,TR,TS,TT,TU,TV,TW,TX,TY,TZ,
UA,UB,UC,UD,UE,UF,UG,UH,UI,UJ,UK,UL,UM,UN,UO,UP,UQ,UR,US,UT,UU,UV,UW,UX,UY,UZ,
VA,VB,VC,VD,VE,VF,VG,VH,VI,VJ,VK,VL,VM,VN,VO,VP,VQ,VR,VS,VT,VU,VV,VW,VX,VY,VZ,
WA,WB,WC,WD,WE,WF,WG,WH,WI,WJ,WK,WL,WM,WN,WO,WP,WQ,WR,WS,WT,WU,WV,WW,WX,WY,WZ,
XA,XB,XC,XD,XE,XF,XG,XH,XI,XJ,XK,XL,XM,XN,XO,XP,XQ,XR,XS,XT,XU,XV,XW,XX,XY,XZ,
YA,YB,YC,YD,YE,YF,YG,YH,YI,YJ,YK,YL,YM,YN,YO,YP,YQ,YR,YS,YT,YU,YV,YW,YX,YY,YZ,
ZA,ZB,ZC,ZD,ZE,ZF,ZG,ZH,ZI,ZJ,ZK,ZL,ZM,ZN,ZO,ZP,ZQ,ZR,ZS,ZT,ZU,ZV,ZW,ZX,ZY,ZZ,
AAA,AAB,AAC,AAD,AAE,AAF,AAG,AAH,AAI,AAJ,AAK,AAL,AAM,AAN,AAO,AAP,AAQ,AAR,AAS,AAT,AAU,AAV,AAW,AAX,AAY,AAZ,
ABA,ABB,ABC,ABD,ABE,ABF,ABG,ABH,ABI,ABJ,ABK,ABL,ABM,ABN,ABO,ABP,ABQ,ABR,ABS,ABT,ABU,ABV,ABW,ABX,ABY,ABZ,
ACA,ACB,ACC,ACD,ACE,ACF,ACG,ACH,ACI,ACJ,ACK,ACL,ACM,ACN,ACO,ACP,ACQ,ACR,ACS,ACT,ACU,ACV,ACW,ACX,ACY,ACZ,
ADA,ADB,ADC,ADD,ADE,ADF,ADG,ADH,ADI,ADJ,ADK,ADL,ADM,ADN,ADO,ADP,ADQ,ADR,ADS,ADT,ADU,ADV,ADW,ADX,ADY,ADZ,
AEA,AEB,AEC,AED,AEE,AEF,AEG,AEH,AEI,AEJ,AEK,AEL,AEM,AEN,AEO,AEP,AEQ,AER,AES,AET,AEU,AEV,AEW,AEX,AEY,AEZ,
AFA,AFB,AFC,AFD,AFE,AFF,AFG,AFH,AFI,AFJ,AFK,AFL,AFM,AFN,AFO,AFP,AFQ,AFR,AFS,AFT,AFU,AFV,AFW,AFX,AFY,AFZ,
AGA,AGB,AGC,AGD,AGE,AGF,AGG,AGH,AGI,AGJ,AGK,AGL,AGM,AGN,AGO,AGP,AGQ,AGR,AGS,AGT,AGU,AGV,AGW,AGX,AGY,AGZ,
AHA,AHB,AHC,AHD,AHE,AHF,AHG,AHH,AHI,AHJ,AHK,AHL,AHM,AHN,AHO,AHP,AHQ,AHR,AHS,AHT,AHU,AHV,AHW,AHX,AHY,AHZ,
AIA,AIB,AIC,AID,AIE,AIF,AIG,AIH,AII,AIJ,AIK,AIL,AIM,AIN,AIO,AIP,AIQ,AIR,AIS,AIT,AIU,AIV,AIW,AIX,AIY,AIZ,
AJA,AJB,AJC,AJD,AJE,AJF,AJG,AJH,AJI,AJJ,AJK,AJL,AJM,AJN,AJO,AJP,AJQ,AJR,AJS,AJT,AJU,AJV,AJW,AJX,AJY,AJZ,
AKA,AKB,AKC,AKD,AKE,AKF,AKG,AKH,AKI,AKJ,AKK,AKL,AKM,AKN,AKO,AKP,AKQ,AKR,AKS,AKT,AKU,AKV,AKW,AKX,AKY,AKZ,
ALA,ALB,ALC,ALD,ALE,ALF,ALG,ALH,ALI,ALJ,ALK,ALL,