String id=request.getParameter( "id ");
String idd=new String(id.getBytes( "ISO-8859-1 ", "UTF-8 "));
------解决方案--------------------
String idd=new String(id.getBytes( "ISO-8859-1 ", "UTF-8 "));
写错了,应该为String idd=new String(id.getBytes( "ISO-8859-1 "), "UTF-8 "));