??class??StringTest{ public??static??void??sop(String??str) { System.out.println(str); } public??static??void??main(String[]??args) { String??s="??????ab?cd??????"; sop("("+s+")"); s=myTrim(s); sop("("+s+")"); } public??static??String??myTrim(String??str) { int??start=0,end=str.length()-1; while(start<=end?&&?str.charAt(start)=='') start++; while(start<=end?&&?str.charAt(end)=='') end--; return?str.substring(start,end+1); }