解决后台向前端Ajax传值乱码问题

<!--注解驱动-->
<mvc:annotation-driven/>

将原来的注解驱动改为:

<!--注解驱动-->
<mvc:annotation-driven>
   <mvc:message-convertersregister-defaults="true">
     <bean class="org.springframework.http.converter.StringHttpMessageConverter">
      <property name="supportedMediaTypes"value="text/plain;charset=UTF-8"/>
     </bean>
   </mvc:message-converters>
</mvc:annotation-driven>