找不到类型匹配的 bean ... 为依赖找到 [英] No matching bean of type ... found for dependency
问题描述
在 springsource 论坛上尝试并等待答案几天后,我将在这里尝试.运行我的应用程序会导致以下异常:
after some days of trying and waitin' for answers on the springsource forums I'll try it here. Running my application results in these exception:
org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [com.example.my.services.user.UserService] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:924)
org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:793)
org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:707)
org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:478)
org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:284)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1106)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:585)
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:913)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464)
org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:631)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:588)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:645)
org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:508)
org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:449)
org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:133)
javax.servlet.GenericServlet.init(GenericServlet.java:212)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
java.lang.Thread.run(Thread.java:662)
这是相关的代码
应用上下文:
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="org.postgresql.Driver" />
<property name="url" value="jdbc:postgresql://localhost:5432/test" />
<property name="username" value="test" />
<property name="password" value="test" />
</bean>
<bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="packagesToScan" value="com.example.my.entities.*" />
<property name="configurationClass" value="org.hibernate.cfg.AnnotationConfiguration" />
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</prop>
<prop key="hibernate.show_sql">true</prop>
</props>
</property>
</bean>
<tx:annotation-driven />
<bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
com.example.my.entities.user:
com.example.my.entities.user:
@Entity
@Table( name = "tbl_users" )
public class User
{
@Id
@Column( name = "id" )
@GeneratedValue
private int id;
@Column( name = "username" )
private String username;
@Column( name = "password" )
private String password;
public void setId( int id )
{
this.id = id;
}
public int getId()
{
return id;
}
public void setUsername( String username )
{
this.username = username;
}
public String getUsername()
{
return username;
}
public void setPassword( String password )
{
this.password = password;
}
public String getPassword()
{
return password;
}
}
服务:
@Service
public class UserServiceImpl implements UserService
{
@Autowired
private UserDAO userDAO;
@Override
@Transactional
public void addUser( User user )
{
userDAO.addUser( user );
}
@Override
@Transactional
public List<User> listUsers()
{
return userDAO.listUsers();
}
@Override
@Transactional
public void removeUser( int id )
{
userDAO.removeUser( id );
}
}
推荐答案
导致这种情况的原因有很多,我没有费心去检查你的整个存储库,所以我要在这里冒险一下.
Multiple things can cause this, I didn't bother to check your entire repository, so I'm going out on a limb here.
首先,如果您使用注解进行配置,您可能会在 com.example.my.services.user.UserService
的实现中缺少注解(@Service 或 @Component).如果您使用(仅)xml,则您可能缺少 <bean>
- UserService 实现的定义.
First off, you could be missing an annotation (@Service or @Component) from the implementation of com.example.my.services.user.UserService
, if you're using annotations for configuration. If you're using (only) xml, you're probably missing the <bean>
-definition for the UserService-implementation.
如果您使用注解并且正确注释了实现,请检查是否扫描了实现所在的包(检查您的 <context:component-scan base-package=
-值).
If you're using annotations and the implementation is annotated correctly, check that the package where the implementation is located in is scanned (check your <context:component-scan base-package=
-value).
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