The values of zerosMatcherNext.group(1) and zerosMatcher.group(1) are being evaluated as String with value 0 but the comparison zerosMatcherNext.group(1) ==  zerosMatcher.group(1) returns false. What is the explanation for such a strange behavior?
UPDATE:
but zerosMatcherNext.group(1).equals(zerosMatcher.group(1)) returns true
 
     
    