Question

我像这样编写一个spring xml架构

<route:urls id="urlHandlerMap">
    <route:url pattern="user/api/**" beforeHandlers="defaultBeforeHandler"/>
</route:urls>

这是我的架构解析器

public class ApiRouteParser extends AbstractSingleBeanDefinitionParser {
    private static String DEFAULT_BEFORE_HANDLER = "defaultBeforeHandler";

    private static String ROUTE_URL_FIELD = "route:url";
    private static String PATTERN_FIELD = "pattern";
    private static String BEFORE_HANDLER_FIELD = "beforeHandlers";

    @Override
    protected Class getBeanClass(Element element) {
        return UrlHandlerMap.class;
    }

    @Override
    protected void doParse(Element element,ParserContext parserContext, BeanDefinitionBuilder builder) {
        NodeList urlList = element.getElementsByTagName(ROUTE_URL_FIELD);
        ManagedMap<String, BeanMetadataElement> urlHandlerMapperDefinition = new ManagedMap<String, BeanMetadataElement>();
        for (int i=0; i < urlList.getLength(); i++){
            Element urlNode = (Element)urlList.item(i);

            String pattern = urlNode.getAttribute(PATTERN_FIELD);
            String beforeHandlers = urlNode.getAttribute(BEFORE_HANDLER_FIELD);

            if (StringUtils.isEmpty(beforeHandlers)){
                beforeHandlers = DEFAULT_BEFORE_HANDLER;
            }


            BeanDefinitionBuilder urlHandlerBuilder = BeanDefinitionBuilder.genericBeanDefinition(UrlHandler.class);

            urlHandlerBuilder.addPropertyValue("beforeHandlerList", parseList(beforeHandlers));
            urlHandlerMapperDefinition.put(pattern, urlHandlerBuilder.getBeanDefinition());
        }
        builder.addPropertyValue("urlHandlerMapper", urlHandlerMapperDefinition);
    }

    private List<BeanMetadataElement> parseList(String handlers){
        List<BeanMetadataElement> definitionList = new ManagedList<BeanMetadataElement>();
        String[] handlerArray = handlers.split(",");
        for (String handler : handlerArray){
            // this handler is inject with @Component
            definitionList.add(new RuntimeBeanReference(handler));
        }
        return definitionList;
    }
}

但是当我跑它时，抛出：

Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'defaultBeforeHandler' available
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition(DefaultListableBeanFactory.java:680)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition(AbstractBeanFactory.java:1183)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:284)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:275)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:351)

这是defaultBeforeHandler

@Component
public class DefaultBeforeHandler extends BaseController implements BeforeHandler {
    private static Logger logger = LoggerFactory.getLogger(DefaultBeforeHandler.class);
    @Override
    public void execute(RouteRequest routeRequest, HttpServletRequest request) throws Exception{
        logger.debug("defaultBeforeHandler");
    }
}

但是当我在xml中定义defaultBeforeHandler时，它会没问题。如何在我的xml解析器中使用@Component注释？

我已在<context:component-scan base-package="com.my.app" />

中配置applicationContext.xml

春季版：4.3

Answer 1

您需要通过配置启用组件扫描。通过注释或XML。 E.g。

org.hibernate.envers packages

该示例将启用注释配置并扫描com.acme.app.services下的包以获取任何带注释的类，并将它们注册为bean。更新该字符串以使包与其中带注释的类匹配。

有关详细信息，请参阅docs。

如何在自定义spring xml模式解析器中设置spring注释bean？

1 个答案: