SpringMVC學習（八）Ajax異步請求

文章目錄

一、Ajax簡介（ Asynchronous JavaScript and XML）

Ajax就是在無需重新加載網頁的情況下，能夠部分更新網頁的技術。

Ajax 不是一種新的編程語言，而是一種用於創建更好更快以及交互性更強的Web應用程序的技術。

使用ajax技術的網頁，通過在後臺服務器進行少量的數據交換，就可以實現異步局部更新。

使用Ajax，用戶可以創建接近本地桌面應用的直接、高可用、更豐富、更動態的Web用戶界面。

Ajax的使用場景：

搜索時搜索補全：

二、使用JQuery開發ajax

搭建測試環境

新建一個Module SpringMVC-Ajax
配置web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">

    <!--配置servlet-->
    <servlet>
        <servlet-name>springmvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:applicationContext.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <!--設置編碼-->
    <filter>
        <filter-name>encoding</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>utf-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>encoding</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

</web-app>

新建一個pojo和controller

//pojo
package com.zyh.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    private String name;
    private int age;
    private String sex;
}

//controller
package com.zyh.controller;

import org.springframework.web.bind.annotation.RestController;

@RestController
public class AjaxController {
}

創建Spring配置文件applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/mvc
        https://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <!--需要配置的->註解驅動、靜態資源過濾、視圖解析器 -->
    <context:component-scan base-package="com.zyh.controller"/>
    <mvc:default-servlet-handler/>
    <mvc:annotation-driven/>
    <!--處理JSON亂碼-->
    <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>

    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/"/>
        <property name="suffix" value=".jsp"/>
    </bean>
</beans>

案例一：

編寫AjaxController

    @RequestMapping("/t2")
    public void test2(String name, HttpServletResponse response) throws IOException {
        System.out.println("parm=>" + name);
        if ("zyh".equals(name)) {
            response.getWriter().print(true);
        } else {
            response.getWriter().print(false);
        }
    }

編寫index.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Ajax</title>
    <%--導入jquery--%>
    <script src="${pageContext.request.contextPath}/statics/js/jquery-3.4.1.js"></script>
    <script>
        function a() {
            $.post({
                url: "${pageContext.request.contextPath}/t2",
                data: {"name": $("#username").val()},
                success: function (data, status) {
                    console.log("data=>" + data);
                    console.log("status=>" + status);
                }
            })
        }
    </script>
</head>
<body>
<%--丟失鼠標焦點的事件--%>
<input type="text" id="username" onblur="a()">
</body>
</html>

啓動Tomcat測試
結果：

案例二：SpringMVC版

編寫實體類：User

package com.zyh.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    private String name;
    private int age;
    private String sex;
}

編寫controller

    @RequestMapping("/t3")
    public List<User> test3() {
        List<User> userList = new ArrayList<User>();
        userList.add(new User("德萊厄斯", 22, "男"));
        userList.add(new User("厄斐琉斯", 16, "男"));
        userList.add(new User("馬爾扎哈", 999, "男"));
        return userList;
    }

編寫頁面：

<%@ 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 () {
            $("#btn").click(function () {
                $.post("${pageContext.request.contextPath}/t3", function (data) {
                    var 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>"
                    }
                    $("#content").html(html);
                });
            });
        });
    </script>
</head>
<body>
<input type="button" id="btn" value="加載數據">
<table>
    <tr>
        <td>姓名</td>
        <td>年齡</td>
        <td>性別</td>
    </tr>
    <%--加載後臺數據--%>
    <tbody id="content">

    </tbody>
</table>
</body>
</html>

測試：

案例三：註冊賬戶提示

編寫Controller

    @RequestMapping("/t4")
    public String test4(String name, String password) {
        String msg = "";
        if (name != null) {
            if ("admin".equals(name)) {
                msg = "OK";
            } else {
                msg = "輸入的用戶名錯誤!";
            }
        }
        if (password != null) {
            if ("123456".equals(password)) {
                msg = "OK";
            } else {
                msg = "輸入的密碼錯誤!";
            }
        }
        return msg;
    }

編寫前端頁面

<%@ 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}/t4",
                data: {"name": $("#username").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}/t4",
                data: {"password": $("#password").val()},
                success: function (data) {
                    if (data.toString() === "OK") {
                        $("#pwdInfo").css("color", "green");
                    } else {
                        $("#pwdInfo").css("color", "red");
                    }
                    $("#pwdInfo").html(data);
                }
            });
        }
    </script>
</head>
<body>

<p>
    用戶名<input type="text" id="username" onblur="a1()">
    <span id="userInfo"></span>
</p>
<p>
    密碼<input type="text" id="password" onblur="a2()">
    <span id="pwdInfo"></span>
</p>
</body>
</html>

啓動Tomcat測試：

SpringMVC學習（八）Ajax異步請求

文章目錄

一、Ajax簡介（ Asynchronous JavaScript and XML）

Ajax的使用場景：

二、使用JQuery開發ajax

搭建測試環境

案例一：

案例二：SpringMVC版

案例三：註冊賬戶提示

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