String s = "48 65 6C 6C 6F";
String[] arr = s.split(" ");
StringBuffer sb = new StringBuffer();
for (int ii=0;ii<arr.length;ii++){
    sb.append((char)Integer.valueOf((arr[ii]), 16).intValue());
}
        
System.out.println(sb.toString());

------解决方案--------------------
汗，我在那个帖中已经回复给你了，在 9 楼上

http://topic.csdn.net/u/20080326/13/9ca1121b-78ff-42ca-8bf5-a254076300bb.html