我正在尝试使用Spring为webapp自动装配一些bean(用于依赖注入)。一个控制器bean包含另一个bean,而另一个bean又持有另一组bean的hashmap。目前,该地图只有一个条目。当我在tomcat中运行并调用服务时,我收到一条错误消息,说第二个bean(保存在控制器中)不是唯一的
No unique bean of type [com.hp.it.km.search.web.suggestion.SuggestionService] is defined: expected single matching bean but found 2: [suggestionService, SuggestionService]
我看不到我在两次定义bean的地方,但是这是Spring的新知识,并且是自动装配的,因此我可能缺少一些基本知识。下面列出的xml和2类的源代码…
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd"> <context:component-scan base-package="com.hp.it.km.search.web.suggestion" /> <mvc:annotation-driven /> <context:annotation-config /> <bean id="SuggestionController" class="com.hp.it.km.search.web.suggestion.SuggestionController"> <property name="service"> <ref bean="SuggestionService" /> </property> </bean> <bean id="SuggestionService" class="com.hp.it.km.search.web.suggestion.SuggestionService"> <property name="indexSearchers"> <map> <entry key="KMSearcher"> <ref bean="KMSearcherBean"></ref></entry> </map> </property> </bean> <bean id="KMSearcherBean" class="com.hp.it.km.search.web.suggestion.SuggestionIndexSearcher"> <constructor-arg index="0" value="KMSearcher" /> <constructor-arg index="1" value="C://dev//workspace//search-restful-webapp//src//main//resources//indexes//keyword" /> </bean>
自动接线控制器和服务Bean的类asscoaite在这里…
@Controller public class SuggestionController { private SuggestionService service; @Autowired public void setService(SuggestionService service) { this.service = service; } public SuggestionService getService() { return service; }
和…
@Component public class SuggestionService { private Map<String, IndexSearcher> indexSearchers = new HashMap<String, IndexSearcher>(); @Autowired public void setIndexSearchers(Map<String, IndexSearcher> indexSearchers) { this.indexSearchers = indexSearchers; } public SuggestionService() { super(); }
请帮忙!
问题是因为你有一个通过@Component注释以及通过XML config创建的类型为RecommendationionService的bean。正如JB Nizet解释的那样,这将导致创建一个通过@Component创建的名称为’suggestionService’的bean和另一个通过XML创建的名称为’SuggestionService’的bean。
当你通过@Autowired引用RecommendationionService时,在你的控制器中,Spring默认情况下会“按类型”自动装配并找到两个类型为’SuggestionService’的bean。
你可以执行以下操作
@Resource("suggestionService") private SuggestionService service;
要么
@Resource("SuggestionService") private SuggestionService service;
两者都应该起作用。第三是肮脏的修复程序,最好通过其他方式解决bean冲突。