SpringMVC中ajax的处理

1、 使用HttpServetResponse来处理

Controller

@Controller
@RequestMapping("/springmvc")
public class AjaxController {

    @RequestMapping("/ajax")
    public void ajax(String name, HttpServletResponse resp) throws IOException {
        resp.setCharacterEncoding("utf-8");
        if("yxxy".equals(name)) {
            resp.getWriter().print("用户名已存在！");
        }else {
            resp.getWriter().print("无人使用，可以注册！");
        }
    }
    
}

Jsp

  <script type="text/javascript" src="js/jquery-3.2.1.min.js"></script>
  <script type="text/javascript">
      $(function() {
          $("#txtName").blur(function() {
              $.post("springmvc/ajax.do", 
                  {'name' : $("#txtName").val()}, 
                  function(result) {
                  $("#txtSpan").html(result)
              });
          });
      });
  </script>
  
    用户名：<input id="txtName" /><span id="txtSpan"></span>

2、 springmvc处理

2.1、导入相关jar包

 

2.2、在springMVC配置文件中配置json转换器

    <!-- 用于将对象转换为JSON -->
    <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.MappingJackson2HttpMessageConverter"></bean>
    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
        <property name="messageConverters">
            <list>
                <ref bean="stringConverter"/>
                <ref bean="jsonConverter"/>
            </list>
        </property>
    </bean>

2.3、Controller

    @RequestMapping("/json")
    @ResponseBody
    public List<User> json() {
        List<User> list = new ArrayList<>();
        list.add(new User(1, "张三", "111"));
        list.add(new User(2, "李四", "222"));
        list.add(new User(3, "王五", "333"));
        return list;
    }

2.4、Jsp

  <script type="text/javascript" src="js/jquery-3.2.1.min.js"></script>
  <script type="text/javascript">
      $(function() {
          $("#btn").click(function() {
              $.post("springmvc/json.do", function(result) {
                  var html = "";
                  for(var i = 0;i < result.length; i++) {
                      html += "<tr><td>"+result[i].id+"</td><td>"+result[i].name+"</td><td>"+result[i].pwd+"</td></tr>"
                  }
                  $("#content").html(html);
              });
          });
      });
  </script>
  
  <input id="btn" value="获取json数据" type="button"/>
   <table width="80%" align="center">
           <tr>
               <td>编号</td>
               <td>姓名</td>
               <td>密码</td>
           </tr>
           <tbody id="content"></tbody>
   </table>