前端：
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>$Title$</title>
</head>
<script type="javascript" src="js/jquery-3.4.1.min.js"/>
<script>
function register(){
var $phoneNum = $("#phoneNum").val();
$.ajax({
url:"PhoneNumServlet",
data:"phoneNum="+$phoneNum,
success:function (result, testStatus) {
if(result=="true"){
alert("该号码已存在!");
}else{
alert("注册成功!");
}
},
error:function (xhr, errorMessage, e) {
alert("系统异常!");
}
})
}
</script>
<body>
号码:<input id="phoneNum" /><br/>
<input type="button" value="注册" onclick="register()" />
</body>
</html>
后端：
@WebServlet(name = "PhoneNumServlet")
public class PhoneNumServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=UTF-8");
String phoneNum = request.getParameter("phoneNum");
PrintWriter out = response.getWriter();
if("18888888888".equals(phoneNum)){
out.write("true");
}else{
out.write("false");
}
out.close();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
}
error：
