Ajax代码
<div class="input-group">
<span class="input-group-addon">身份证号</span>
<input type="text" class="form-control" name="cardId" id="cardId" placeholder="请输入身份证号" maxlength="18" required "check_cardId(this.value);">
<span class="msg" id="cardId_msg"></span>
</div>
<script>
var cardId1 = document.getElementById("cardId");
function check_cardId(val){
var cardId = document.getElementById("cardId");
$.ajax({
type: "POST", //发送方式
url: "stuServlet?method=check", //发送地址
data: "cardId=" + val, //形成一对key-value,提交对象可以通过request.getParameter("cardId");获得val值
success: function(data){ //提交成功后调用的方法
var info = "";
if(data == "true"){//后台返回表示重名
info = "已存在";
}
/*else if(data == "false"){
info = "可以注册";
}*/
$("#cardId_msg").html(info);
}
});
}
</script>
servlet代码,在doPost()方法中,具体业务、数据库操作略
/*可以通过System.out.println(cardId);来观察控制台是否获取到值*/
String cardId = request.getParameter("cardId"); //获取cardId
/*可以通过System.out.println(StuService.getStudentByCardId(cardId));来观察控制台是否获取到值*/
response.getWriter().print(StuService.getStudentByCardId(cardId));
response.getWriter().close();