试试这个吧
char oneLetter='A'; //A---65 a---97
int index=0;
int letterLength=26;
int A_value=65,
a_value=97;
while(index<(a_value+letterLength-A_value)){
if(index>=letterLength&&index System_out.println(); }else{ System_out.print(oneLetter); } oneLetter++; index++; }