/**输入手机号码后判断手机号是否存在*/

@RequestMapping(value="/getphone",produces = "text/plain;charset=utf-8")

@ResponseBody

public String getphone(String phone,HttpSession session){

      Users u=service.selectPhoneService(phone);

      if(u==null){//如果为空，则需要注册

            String str="请您先注册，再登录。";

            session.setAttribute("str", str);

            return "请您先注册，再登录。";

      }

      return "true";

}

<!-- 处理请求返回json字符串的中文乱码问题 -->

<mvc:annotation-driven>

<mvc:message-converters>

<bean class="org.springframework.http.converter.StringHttpMessageConverter">

<property name="supportedMediaTypes">

<list>

<value>application/json;charset=UTF-8</value>

</list>

</property>

</bean>

</mvc:message-converters>

</mvc:annotation-driven>