java - Spring MessageSource 进入服务

Question

如果我将最后一个放在 Controller 之外但放在这样的服务内，我会遇到使用 MessageSource 读取属性的问题:

@Service
public class MessageHandler {

    private static final Logger logger = LoggerFactory.getLogger(MessageHandler.class);

    @Autowired
    private static MessageSource messageSource;

    public static void returnMessage(String key, Locale locale) {
        logger.info(key);
        logger.info(locale.toString());
        logger.info(messageSource.getMessage(key, null, locale));
    }

}

此服务位于:com.test.rest.utility

servlet-context.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/mvc"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:beans="http://www.springframework.org/schema/beans"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
        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.xsd">

    <!-- DispatcherServlet Context: defines this servlet's request-processing infrastructure -->

    <!-- Enables the Spring MVC @Controller programming model -->
    <annotation-driven />

    <!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources directory -->
    <resources mapping="/resources/**" location="/resources/" />    

    <!-- Resolves views selected for rendering by @Controllers to .jsp resources in the /WEB-INF/views directory -->
    <beans:bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <beans:property name="prefix" value="/WEB-INF/views/" />
        <beans:property name="suffix" value=".jsp" />
    </beans:bean>

    <beans:bean id="messageSource"
        class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
        <beans:property name="basename" value="classpath:properties/welcome" />
        <beans:property name="fallbackToSystemLocale" value="false" />  
    </beans:bean>

    <beans:bean id="localeResolver"
        class="org.springframework.web.servlet.i18n.CookieLocaleResolver">
        <beans:property name="defaultLocale" value="en" />
    </beans:bean>

    <interceptors>
        <beans:bean
            class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor">
            <beans:property name="paramName" value="lang" />
        </beans:bean>
    </interceptors>


    <beans:bean id="userService" class="com.test.rest.dao.UserDaoImpl" />

    <context:component-scan base-package="com.test.rest.utility" />
    <context:component-scan base-package="com.test.rest.controller" />



</beans:beans>

调用服务的 Controller :

@RequestMapping(value = "/", method = RequestMethod.GET)
    public @ResponseBody  List<Project> home(Locale locale, Model model) {
        String key = "message";
        MessageHandler.returnMessage(key, locale);
}

当进入服务调用 messageSource.getMessage(key, null, locale) 时，应用程序返回 NullPointerException

谁能帮我解决这个问题？

Answer 1

你应该添加<context:component-scan base-package="package where services is located"/>扫描您的服务并将其配置为 spring bean，然后它将可用于其他 beans