Ajax 学习总结_牛客博客

Ajax 学习总结

一、Ajax包的导入

二、Ajax的异步请求

在使用时要引用

 <script src="${pageContext.request.contextPath}/statics/js/jquery-3.4.1.js"></script>

后台添加的数据

  @RequestMapping("/a2")
    public List<User> a2(){
   
        List<User> listuser=new ArrayList<User>();

        //添加数据
        listuser.add(new User("小明1",12,"男"));
        listuser.add(new User("小明2",13,"男"));
        listuser.add(new User("小明3",14,"男"));
        listuser.add(new User("小明4",18,"男"));
        return listuser;
    }

前端拿到数据

 <script>
        $(function () {
   
            $("#btn").click(function () {
   
               $.post({
   
                   url:"${pageContext.request.contextPath}/a2",
                   success:function (data) {
   
                       //console.log(data);
                       let html="";
                       for (let i=0;i<data.length;i++){
   
                           html +="<tr>"+
                                   "<td>"+data[i].name+"</td>"+
                                   "<td>"+data[i].age+"</td>"+
                                   "<td>"+data[i].sex+"</td>"+
                                   "</tr>"
                       }
                       $("#context").html(html)
                   }
               })
            })
            
        })
    </script>

注意点：

url：为前端请求后端数据接口
data：前端传入到后端的值，可以省略
succcess：数据请求成功后从后端拿到数据
数据的拼接：html +="<tr>"+
     "<td>"+data[i].name+"</td>"+
     "<td>"+data[i].age+"</td>"+
     "<td>"+data[i].sex+"</td>"+
 "</tr>"

三、Ajax 表单验证

Json乱码问题解决

 <!--Json乱码问题解决-->
    <mvc:annotation-driven>
        <mvc:message-converters register-defaults="true">
            <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                <constructor-arg value="UTF-8"/>
            </bean>
            <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
                <property name="objectMapper">
                    <bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
                        <property name="failOnEmptyBeans" value="false"/>
                    </bean>
                </property>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>

表单获取后端的数据

 function a1() {
   
           $.post({
   
               url:"${pageContext.request.contextPath}/a3",
               data:{
   "name":$("#name").val()},
               success:function (data) {
   
                  if (data.toString()=='ok'){
   
                     $("#userInfo").css("color","green");
                  }else {
   
                      $("#userInfo").css("color","red");
                  }
                  $("#userInfo").html(data);
               }
           })
        }

表单校验


<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
    <script src="${pageContext.request.contextPath}/statics/js/jquery-3.4.1.js"></script>
    <script>
        function a1() {
   
           $.post({
   
               url:"${pageContext.request.contextPath}/a3",
               data:{
   "name":$("#name").val()},
               success:function (data) {
   
                  if (data.toString()=='ok'){
   
                     $("#userInfo").css("color","green");
                  }else {
   
                      $("#userInfo").css("color","red");
                  }
                  $("#userInfo").html(data);
               }
           })
        }
        function a2() {
   
            $.post({
   
                url:"${pageContext.request.contextPath}/a3",
                data:{
   "pwd":$("#pwd").val()},
                success:function (data) {
   
                    if (data.toString()=='ok'){
   
                        $("#pwdInfo").css("color","green");
                    }else {
   
                        $("#pwdInfo").css("color","red");
                    }
                    $("#pwdInfo").html(data);
                }
            })
        }
    </script>
</head>
<body>
    <p>
        用户名：<input type="text" id="name" onblur="a1()">
        <span id="userInfo"></span>
        <%--onblur失去焦点事件--%>
    </p>
    <p>
        密码：<input type="text" id="pwd" onblur="a2()">
        <span id="pwdInfo"></span>
        <%--onblur失去焦点事件--%>
    </p>
</body>
</html>

好了，今天的分享就到这里了哦