什么是Ajax
- 异步的 JavaScript 和 XML
- 不是一种新的编程语言，而是一种用于创建更好更快以及交互性更强的Web应用程序的技术。
- 是一种在无需重新加载整个网页的情况下，能够更新部分网页的技术。
Ajax的使用
- 引入jQery，使用jQery.ajax()
<script src="${pageContext.request.contextPath}/statics/js/jquery-3.6.0.js"></script>
- springmvc的配置文件记得加上JSON乱码过滤
<mvc:annotation-driven>
<mvc:message-converters register-defaults="true">
<bean class="org.springframework.http.converter.StringHttpMessageConverter">
<constructor-arg value="UTF-8"/>
</bean>
<bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<property name="objectMapper">
<bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
<property name="failOnEmptyBeans" value="false"/>
</bean>
</property>
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
- 编写业务控制类
package controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import pojo.User;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
@RestController
public class AjaxController {
@RequestMapping("/a1")
public void ajax1(String name , HttpServletResponse response) throws IOException {
if ("admin".equals(name)){
response.getWriter().print("true");
}else{
response.getWriter().print("false");
}
}
}
- 编写index.jsp测试Ajax
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Ajax体验</title>
<script src="${pageContext.request.contextPath}/statics/js/jquery-3.6.0.js"></script>
<script>
function a1(){
$.post({
url:"${pageContext.request.contextPath}/a1",
data:{'name':$("#Name").val()},
success:function (data,status) {
alert(data);
alert(status);
}
});
}
</script>
</head>
<body>
<%--onblur：失去焦点触发事件--%>
用户名:<input type="text" id="Name" onblur="a1()"/>
</body>
</html>
springmvc使用Ajax
- 创建一个实体类
package pojo;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
private int id;
private String name;
private int age;
}
- 编写业务控制类
package controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import pojo.User;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
@RestController
public class AjaxController {
@RequestMapping("/a2")
public List<User> ajax2(){
List<User> userList = new ArrayList<User>();
userList.add(new User(1,"xiaomi",21));
userList.add(new User(2,"xiaohu",22));
userList.add(new User(3,"xiaoming",23));
return userList;
}
}
- 编写test.jsp测试
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
<script src="${pageContext.request.contextPath}/statics/js/jquery-3.6.0.js"></script>
<script>
$(function () {
$("#btn").click(function () {
$.post("${pageContext.request.contextPath}/a2", function (data) {
console.log(data)
var html = "";
for (var i = 0; i < data.length; i++) {
html += "<tr>" +
"<td>" + data[i].id + "</td>" +
"<td>" + data[i].name + "</td>" +
"<td>" + data[i].age + "</td>" +
"</tr>"
}
$("#content").html(html);
});
})
})
</script>
</head>
<body>
<input type="button" id="btn" value="获取数据">
<table>
<tr>
<td>编号</td>
<td>姓名</td>
<td>性别</td>
</tr>
<tbody id="content">
</tbody>
</table>
</body>
</html>
再来一个常见的Ajax，登录页面提示
- 业务控制类
package controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import pojo.User;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
@RestController
public class AjaxController {
@RequestMapping("/a3")
public String ajax3(String name,String pwd){
String msg = "";
if (name!=null){
if ("admin".equals(name)){
msg = "OK";
}else {
msg = "用户名输入错误";
}
}
if (pwd!=null){
if ("123456".equals(pwd)){
msg = "OK";
}else {
msg = "密码输入有误";
}
}
return msg;
}
}
- 编写login.jsp测试
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
<script src="${pageContext.request.contextPath}/statics/js/jquery-3.6.0.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>
</p>
<p>
密码:<input type="text" id="pwd" onblur="a2()"/>
<span id="pwdInfo"></span>
</p>
</body>
</html>
