微信公众号的开发 该公众号提供的服务出现故障，请稍后再试

<!-- 使用spring mvc注解 -->
    <mvc:annotation-driven>
     <mvc:message-converters>
   <bean class="org.springframework.http.converter.StringHttpMessageConverter">
    <property name="supportedMediaTypes">
                    <list>
                        <value>text/html;charset=UTF-8</value>
                    </list>
                </property>
   </bean>
   <ref bean="mappingJacksonHttpMessageConverter" />
   <bean class="org.springframework.http.converter.FormHttpMessageConverter"></bean>
     </mvc:message-converters>
 </mvc:annotation-driven>

很多人都碰到过，SpringMVC使用 @ResponseBody 注解，返加字符串不做任何处理时，有可能会出现乱码问题。

这是由于 StringHttpMessageConverter 类中，默认采用的字符集是 ISO-8859-1。

public class StringHttpMessageConverter extends AbstractHttpMessageConverter<String> {

   public static final Charset DEFAULT_CHARSET = Charset.forName("ISO-8859-1");


   private final Charset defaultCharset;

   private final List<Charset> availableCharsets;

   private boolean writeAcceptCharset = true;


   /**
    * A default constructor that uses {@code "ISO-8859-1"} as the default charset.
    * @see #StringHttpMessageConverter(Charset)
    */
   public StringHttpMessageConverter() {
      this(DEFAULT_CHARSET);
   }

那么要解决乱码问题，需要改变 StringHttpMessageConverter 中的默认字符集，本文中以UTF-8为例。

修改默认字付集：

<bean id="stringHttpMessageConverter" class="org.springframework.http.converter.StringHttpMessageConverter">
    <constructor-arg value="UTF-8" index="0"/>
    <property name="supportedMediaTypes">
        <list>
            <value>text/plain;charset=UTF-8</value>
        </list>
    </property>
</bean>

配置起效

方式一：

<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping"/>
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
    <property name="messageConverters">
        <list>
            <ref bean="stringHttpMessageConverter"/>
            <ref bean="jackson2HttpMessageConverter"/>
        </list>
    </property>
</bean>

<mvc:annotation-driven />

注：配置必须在 <mvc:annotation-driven /> 之前，否则将不会启效；<mvc:annotation-driven /> 会自动注册DefaultAnnotationHandlerMapping 与AnnotationMethodHandlerAdapter。

方式二：

<mvc:annotation-driven>
    <mvc:message-converters>
        <ref bean="stringHttpMessageConverter"/>
        <ref bean="jackson2HttpMessageConverter"/>
    </mvc:message-converters>
</mvc:annotation-driven>