差的資。料說是用ajax做？可是我不會ajax，ajax實(shí)在不會寫了。。。html部分<p>        <label>編號：</label> <input name="custom_number" type="text" size="30" id="custom_number"                    value="<%=item.getCustom_number() == null ? "" : item.getCustom_number()%>"                    maxlength="50" /></p>javascript部分<script>$('#custom_number').change(function(){                    $.ajax({            url: '<%=basePath%>admin/custom/repeat.html?custom_number=' + $('#custom_number').val(),        dataType: 'post',                });</script>后臺數(shù)據(jù)庫代碼 @RequestMapping(value = "/repeat")     public void repeat(HttpServletRequest request, HttpServletResponse response, String custom_number) throws SQLException, IOException{         ConnectionSource connectionSource = DBUtil.getConnectionSource();                  Dao<zqbp_custom, String> dao = DaoManager.createDao(connectionSource,                 zqbp_custom.class);                  QueryBuilder<zqbp_custom, String> where = dao.queryBuilder();         List<zqbp_custom> list = where.where().eq("custom_number", custom_number).query();         if(list.size()==0){                      }else {             response.getWriter().write("編號重復(fù)，請重新輸入");              response.getWriter().close();        }     }