Springmvc中ajax與jason應用

時間 2019-11-13

原文原文鏈接

Springmvc中ajax與jason應用

未涉及json的ajax請求

簡單的表單驗證git

Controller層java代碼

@Controller
public class AjaxCtrl {
    @RequestMapping("/toAjax.do")
    public String toAjax() {
        return "ajax";
    }
    @RequestMapping("/ajax.do")
    @ResponseBody
    public void ajaxJson(@RequestParam("name")String name,HttpServletResponse resp) throws IOException {
        PrintWriter out = resp.getWriter();
        if(name.equals("hm"))
            out.print("該用戶已註冊");
        else
            out.print("該用戶可以使用");
    }

注意點：github

在手動調用getWriter()方法時不能夠再添加返回值，不然tomcat會報錯（getWriter()方法已存在）。由於在返回值處容器會自動調用getWriter()方法來輸出內容，而檢測到前面getWriter()已經被調用過，產生衝突。
解決：1. 像上面的代碼不給出返回值；2. resp.reset(); resp.setContentType("text/html; charset=utf-8"); out.flush; out.close();
@ResponseBody會將返回的數據自動轉換爲json格式的數據web

相關jsp代碼：ajax.jsp

<script src="${pageContext.request.contextPath }/js/jquery-2.1.0.min.js" type="text/javascript"></script>
</head>
<body>
    姓名：<input type="text" id="field" name="name" /><span id="txt"></span>
    <script type="text/javascript">
        $("#field").blur(function(){
            $.post("ajax.do",{'name':$('#field').val()},function(result){
                $("#txt").html(result);
            });
        });
    </script>
</body>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
    id="WebApp_ID" version="3.1">
    <display-name>springmvc_ajax</display-name>
    <filter>
        <filter-name>characterencoding</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>
        <init-param>
            <param-name>forceEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>characterencoding</filter-name>
        <url-pattern>*.do</url-pattern>
    </filter-mapping>
    <servlet>
        <servlet-name>ajax</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:mvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>ajax</servlet-name>
        <url-pattern>*.do</url-pattern>
    </servlet-mapping>
</web-app>

涉及json格式數據的ajax請求

Controller層java代碼

@RequestMapping("/toAjaxJson.do")
    public String toAjaxJson() {
        return "ajaxJson";
    }
    @RequestMapping("/ajaxJson.do")
    @ResponseBody
    public List<User> ajaxJson() {
        List<User> list = new ArrayList<User>();
        list.add(new User(1, "xb", "123"));
        list.add(new User(2, "xc", "234"));
        list.add(new User(3, "xd", "345"));
        list.add(new User(4, "xa", "456"));
        return list;
    }

相關jsp代碼：ajaxJson.jsp

<input type="button" id="btn" value="獲取json數據">
    <table  width="80%" align="center">
        <tr>
            <th>編號</th>
            <th>姓名</th>
            <th>密碼</th>
        </tr>
        <tbody id="content"></tbody>
    </table>
    <script type="text/javascript">
    $(function(){
        $("#btn").click(function(){
            $.get("ajaxJson.do",function(list){
                var field = "";
                for (var i = 0; i < list.length; i++) {
                    field +="<tr><td>"+list[i].id+"</td>"+"<td>"+list[i].name+"</td>"+"<td>"+list[i].passwd+"</td></tr>";
                }
                $("#content").html(field);
            });
        });
    });
    </script>

springmvc的核心配置文件：mvc.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 http://www.springframework.org/schema/context/spring-context-4.1.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd">
    <!-- 開啓mvc的註解 -->
    <mvc:annotation-driven />
    <!-- 掃描包 -->
    <context:component-scan base-package="com.zrm.controller"></context:component-scan>
    <!-- 配置視圖解析器 -->
    <bean id="InternalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/views/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>
    <bean id="stringConverter" class="org.springframework.http.converter. StringHttpMessageConverter">
        <property name="supportedMediaTypes">
            <list>
                <value>text/plain;charset=UTF-8</value>
            </list>
        </property>
    </bean>
    <bean id="jsonConverter" class="org.springframework.http.converter.json. "></bean>
    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
        <property name="messageConverters">
            <list>
                <ref bean="stringConverter"/>
                <ref bean="jsonConverter"/>
            </list>
        </property>
    </bean> 
</beans>