Java : find all combinations of strings character by character : If I have for instance

CAT,

In JAVA, I want all possible combinations of characters with 1 character change at a time (excluding the combination CAT):

    AAT
    BAT
    DAT
    EAT
    .
    .
    .
    ZAT
    
    CBT
    CCT
    CDT
    .
    .
    .
    CZT
   
    CAA
    CAB
    CAC
    .
    .
    .
    CAZ




