问题描述
背景：项目使用maven管理，如下是依赖jar树结构：
[INFO] xxx:groupon-boot:jar:1.0[INFO] +- org.springframework.boot:spring-boot-starter-web:jar:1.2.0.RELEASE:compile[INFO] | +- org.springframework.boot:spring-boot-starter:jar:1.2.0.RELEASE:compile[INFO] | | +- org.springframework.boot:spring-boot:jar:1.2.0.RELEASE:compile[INFO] | | +- org.springframework.boot:spring-boot-autoconfigure:jar:1.2.0.RELEASE:compile[INFO] | | +- org.springframework.boot:spring-boot-starter-logging:jar:1.2.0.RELEASE:compile[INFO] | | | +- org.slf4j:jul-to-slf4j:jar:1.7.7:compile[INFO] | | | +- org.slf4j:log4j-over-slf4j:jar:1.7.7:compile[INFO] | | | - ch.qos.logback:logback-classic:jar:1.1.2:compile[INFO] | | | - ch.qos.logback:logback-core:jar:1.1.2:compile[INFO] | | - org.yaml:snakeyaml:jar:1.14:runtime[INFO] | +- org.springframework.boot:spring-boot-starter-tomcat:jar:1.2.0.RELEASE:compile[INFO] | | +- org.apache.tomcat.embed:tomcat-embed-core:jar:8.0.15:compile[INFO] | | +- org.apache.tomcat.embed:tomcat-embed-el:jar:8.0.15:compile[INFO] | | +- org.apache.tomcat.embed:tomcat-embed-logging-juli:jar:8.0.15:compile[INFO] | | - org.apache.tomcat.embed:tomcat-embed-websocket:jar:8.0.15:compile[INFO] | +- com.fasterxml.jackson.core:jackson-databind:jar:2.4.4:compile[INFO] | | +- com.fasterxml.jackson.core:jackson-annotations:jar:2.4.4:compile[INFO] | | - com.fasterxml.jackson.core:jackson-core:jar:2.4.4:compile[INFO] | +- org.hibernate:hibernate-validator:jar:5.1.3.Final:compile[INFO] | | +- javax.validation:validation-api:jar:1.1.0.Final:compile[INFO] | | +- org.jboss.logging:jboss-logging:jar:3.1.3.GA:compile[INFO] | | - com.fasterxml:classmate:jar:1.0.0:compile[INFO] | +- org.springframework:spring-core:jar:4.1.3.RELEASE:compile[INFO] | +- org.springframework:spring-web:jar:4.1.3.RELEASE:compile[INFO] | | +- org.springframework:spring-aop:jar:4.1.3.RELEASE:compile[INFO] | | | - aopalliance:aopalliance:jar:1.0:compile[INFO] | | +- org.springframework:spring-beans:jar:4.1.3.RELEASE:compile[INFO] | | - org.springframework:spring-context:jar:4.1.3.RELEASE:compile[INFO] | - org.springframework:spring-webmvc:jar:4.1.3.RELEASE:compile[INFO] | - org.springframework:spring-expression:jar:4.1.3.RELEASE:compile[INFO] +- org.springframework.boot:spring-boot-starter-redis:jar:1.2.0.RELEASE:compile[INFO] | +- org.springframework:spring-context-support:jar:4.1.3.RELEASE:compile[INFO] | +- org.springframework:spring-tx:jar:4.1.3.RELEASE:compile[INFO] | +- org.springframework.data:spring-data-redis:jar:1.4.1.RELEASE:compile[INFO] | | - org.slf4j:slf4j-api:jar:1.7.7:compile[INFO] | - redis.clients:jedis:jar:2.5.2:compile[INFO] | - org.apache.commons:commons-pool2:jar:2.2:compile[INFO] +- org.springframework.boot:spring-boot-starter-data-jpa:jar:1.2.0.RELEASE:compile[INFO] | +- org.springframework.boot:spring-boot-starter-aop:jar:1.2.0.RELEASE:compile[INFO] | | +- org.aspectj:aspectjrt:jar:1.8.4:compile[INFO] | | - org.aspectj:aspectjweaver:jar:1.8.4:compile[INFO] | +- org.springframework.boot:spring-boot-starter-jdbc:jar:1.2.0.RELEASE:compile[INFO] | | +- org.springframework:spring-jdbc:jar:4.1.3.RELEASE:compile[INFO] | | - org.apache.tomcat:tomcat-jdbc:jar:8.0.15:compile[INFO] | | - org.apache.tomcat:tomcat-juli:jar:8.0.15:compile[INFO] | +- org.hibernate:hibernate-entitymanager:jar:4.3.7.Final:compile[INFO] | | +- org.jboss.logging:jboss-logging-annotations:jar:1.2.0.Beta1:compile[INFO] | | +- org.hibernate:hibernate-core:jar:4.3.7.Final:compile[INFO] | | | +- antlr:antlr:jar:2.7.7:compile[INFO] | | | - org.jboss:jandex:jar:1.1.0.Final:compile[INFO] | | +- org.hibernate.common:hibernate-commons-annotations:jar:4.0.5.Final:compile[INFO] | | +- org.hibernate.javax.persistence:hibernate-jpa-2.1-api:jar:1.0.0.Final:compile[INFO] | | +- org.jboss.spec.javax.transaction:jboss-transaction-api_1.2_spec:jar:1.0.0.Final:compile[INFO] | | - org.javassist:javassist:jar:3.18.1-GA:compile[INFO] | +- org.springframework:spring-orm:jar:4.1.3.RELEASE:compile[INFO] | +- org.springframework.data:spring-data-jpa:jar:1.7.1.RELEASE:compile[INFO] | | +- org.springframework.data:spring-data-commons:jar:1.9.1.RELEASE:compile[INFO] | | - org.slf4j:jcl-over-slf4j:jar:1.7.7:compile[INFO] | - org.springframework:spring-aspects:jar:4.1.3.RELEASE:compile[INFO] +- org.hsqldb:hsqldb:jar:2.3.2:runtime[INFO] - witcool:groupon-mongodb:jar:1.0:compile[INFO] +- witcool:yqsp-mongo-common:jar:1.0:compile[INFO] | +- witcool:yqsp-common:jar:1.0:compile[INFO] | | +- org.apache.httpcomponents:httpcore:jar:4.3.2:compile[INFO] | | +- org.apache.httpcomponents:httpclient:jar:4.3.6:compile[INFO] | | +- org.apache.httpcomponents:httpmime:jar:4.3.6:compile[INFO] | | - commons-configuration:commons-configuration:jar:1.6:compile[INFO] | | +- commons-collections:commons-collections:jar:3.2.1:compile[INFO] | | +- commons-digester:commons-digester:jar:2.1:compile[INFO] | | | - commons-beanutils:commons-beanutils:jar:1.9.2:compile[INFO] | | - commons-beanutils:commons-beanutils-core:jar:1.8.0:compile[INFO] | +- org.springframework:spring-test:jar:4.1.3.RELEASE:compile[INFO] | +- org.springframework.security:spring-security-core:jar:3.2.5.RELEASE:compile[INFO] | +- org.springframework.security:spring-security-web:jar:3.2.5.RELEASE:compile[INFO] | +- org.springframework.security:spring-security-config:jar:3.2.5.RELEASE:compile[INFO] | +- org.springframework.security:spring-security-taglibs:jar:3.2.5.RELEASE:compile[INFO] | | - org.springframework.security:spring-security-acl:jar:3.2.5.RELEASE:compile[INFO] | +- org.springframework.security.oauth:spring-security-oauth2:jar:1.0.5.RELEASE:compile[INFO] | +- javax.annotation:com.springsource.javax.annotation:jar:1.0.0:compile[INFO] | +- javax.inject:javax.inject:jar:1:compile[INFO] | +- mysql:mysql-connector-java:jar:5.1.34:compile[INFO] | +- commons-dbcp:commons-dbcp:jar:1.4:compile[INFO] | +- org.slf4j:slf4j-log4j12:jar:1.7.7:runtime[INFO] | +- log4j:log4j:jar:1.2.17:compile[INFO] | +- org.glassfish.jersey.media:jersey-media-json-jackson:jar:2.13:compile[INFO] | | - org.glassfish.jersey.core:jersey-common:jar:2.13:compile[INFO] | | +- javax.ws.rs:javax.ws.rs-api:jar:2.0.1:compile[INFO] | | +- javax.annotation:javax.annotation-api:jar:1.2:compile[INFO] | | +- org.glassfish.jersey.bundles.repackaged:jersey-guava:jar:2.13:compile[INFO] | | +- org.glassfish.hk2:hk2-api:jar:2.3.0-b10:compile[INFO] | | | +- org.glassfish.hk2:hk2-utils:jar:2.3.0-b10:compile[INFO] | | | - org.glassfish.hk2.external:aopalliance-repackaged:jar:2.3.0-b10:compile[INFO] | | +- org.glassfish.hk2.external:javax.inject:jar:2.3.0-b10:compile[INFO] | | +- org.glassfish.hk2:hk2-locator:jar:2.3.0-b10:compile[INFO] | | - org.glassfish.hk2:osgi-resource-locator:jar:1.0.1:compile[INFO] | +- com.fasterxml.jackson.jaxrs:jackson-jaxrs-json-provider:jar:2.3.2:compile[INFO] | +- com.fasterxml.jackson.jaxrs:jackson-jaxrs-base:jar:2.3.2:compile[INFO] | +- com.fasterxml.jackson.module:jackson-module-jaxb-annotations:jar:2.3.2:compile[INFO] | - cglib:cglib:jar:2.2.2:compile[INFO] | - asm:asm:jar:3.3.1:compile[INFO] +- org.springframework.data:spring-data-mongodb:jar:1.6.1.RELEASE:compile[INFO] | - org.mongodb:mongo-java-driver:jar:2.12.4:compile[INFO] +- commons-httpclient:commons-httpclient:jar:3.1:compile[INFO] | - commons-logging:commons-logging:jar:1.0.4:compile[INFO] +- commons-lang:commons-lang:jar:2.6:compile[INFO] +- commons-codec:commons-codec:jar:1.6:compile[INFO] +- org.codehaus.jackson:jackson-core-asl:jar:1.8.4:compile[INFO] +- org.codehaus.jackson:jackson-mapper-asl:jar:1.8.4:compile[INFO] +- dom4j:dom4j:jar:1.6.1:compile[INFO] | - xml-apis:xml-apis:jar:1.0.b2:compile[INFO] - javax.servlet:javax.servlet-api:jar:3.1.0:compile
如下是spring配置文件：
<?xml version='1.0' encoding='UTF-8'?><beans xmlns='http://www.springframework.org/schema/beans'xmlns:context='http://www.springframework.org/schema/context'xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'xmlns:p='http://www.springframework.org/schema/p'xmlns:c='http://www.springframework.org/schema/c' xmlns:repository='http://www.springframework.org/schema/data/repository'xmlns:mongo='http://www.springframework.org/schema/data/mongo'xsi:schemaLocation='http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/data/repositoryhttp://www.springframework.org/schema/data/repository/spring-repository.xsdhttp://www.springframework.org/schema/data/mongohttp://www.springframework.org/schema/data/mongo/spring-mongo.xsd'><context:component-scan base-package='com.xxx.groupon' /><!-- Factory bean that creates the Mongo instance --><bean class='org.springframework.data.mongodb.core.MongoFactoryBean'> <property name='host' value='localhost' /> <property name='port' value='27017' /></bean><bean class='org.springframework.data.mongodb.core.MongoTemplate'> <constructor-arg name='mongo' ref='mongo' /> <constructor-arg name='databaseName' value='groupon3' /></bean><bean class='org.springframework.data.mongodb.core.MongoTemplate'> <constructor-arg name='mongo' ref='mongo' /> <constructor-arg name='databaseName' value='sequences3' /></bean>问题：
执行打好的jar包后，报如下错误：No qualifying bean of type [org.springframework.data.mongodb.core.MongoTemplate] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency.
我的想法是通过上面的jar树和配置文件，证明我已经依赖了spring-data-mongodb包。那为什么仍然会提示我MongoTemplate没有定义？
更新：感谢@Kavlez同学提醒和@XFHNever同学帮忙，的确是没有加载到配置文件，给入口类添加@ImportResource('applicationContext.xml')
加载成功后，又报NoUniqueBeanDefinitionException异常，描述为No qualifying bean of type [org.springframework.data.mongodb.core.MongoTemplate] is defined: expected single matching bean but found 2: sequenceTemplate,grouponTemplate
但此时我注入的方式是@Autowired和@Qualifier('grouponTemplate')配合（在其他spring项目中这样做没有问题的）但为什么仍然会报NoUniqueBeanDefinitionException呢？
好吧，问题的原因没有找到，倒是让我侥幸解决了：在spring配置文件中新添加了一个bean：
<bean class='org.springframework.data.mongodb.core.MongoTemplate'><constructor-arg name='mongo' ref='mongo' /><constructor-arg name='databaseName' value='test' /> </bean>
项目跑了起来～
最后，如果有幸得知该问题的原因，我更新在这个问题下面。再次感谢。
问题解答
回答1：从题主提供的信息来看，在Spring配置文件中声明的两个MongoTemplate都没有detect到。如果按 @XFHNever 同学所说，是因为同时配置了两个相同类型的Bean，而无法识别要Autowire的是哪一个，这种情况下异常信息应该是：
org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [org.springframework.data.mongodb.core.MongoTemplate] is defined: expected single matching bean but found 2
我猜测可能是没有读到该配置文件。
回答2：这个应该是因为你在配置文件中配置了两个MongoTemplate，然后Spring不知道应该加载哪个，可以考虑同时使用@Autowired和@Qualifier来指定具体加载哪个MongoTemplate。
PS：
@Resource默认是按照名称来装配注入的，只有当找不到与名称匹配的bean才会按照类型来装配注入； @Resource(name='studentDao')@Autowired默认是按照类型装配注入的，如果想按照名称来转配注入，则需要结合@Qualifier一起使用； @Autowired @Qualifier('studentDao')@Resource注解是由J2EE提供，而@Autowired是由Spring提供，故减少系统对spring的依赖建议使用 @Resource的方式；回答3：http://www.jianshu.com/p/6c82e6e21e5d我之前总结的文章，你可以看看
