returns a string , of length at least minlength , consisting of string prependedwith as many copies of padchar as are necessary to reach that length . for example , padstart `` 7 '' , 3 , ' 0 ' returns `` 007 '' padstart `` 2010 '' , 3 , ' 0 ' returns `` 2010 '' see java.util.formatter for a richer set of formatting capabilities . concode_field_sep PlaceHolder placeHolder concode_field_sep String nullToEmpty concode_elem_sep String commonPrefix concode_elem_sep boolean isNullOrEmpty concode_elem_sep boolean validSurrogatePairAt concode_elem_sep String repeat concode_elem_sep String commonSuffix concode_elem_sep String emptyToNull concode_elem_sep String padEnd