異常

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'loginController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.xxx.service.ILoginService com.xxx.controller.LoginController.loginService; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException
 
: No qualifying bean of type [com.xxx.service.ILoginService] 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)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java
 
:334) ~[spring-beans-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1202) ~[spring-beans-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java
 
:537) ~[spring-beans-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476) ~[spring-beans-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302) ~[spring-beans-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298) ~[spring-beans-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193) ~[spring-beans-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:762) ~[spring-beans-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757) ~[spring-context-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480) ~[spring-context-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:663) [spring-webmvc-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:629) [spring-webmvc-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:677) [spring-webmvc-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:548) [spring-webmvc-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:489) [spring-webmvc-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136) [spring-webmvc-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at javax.servlet.GenericServlet.init(GenericServlet.java:158) [servlet-api.jar:3.0.FR]
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1269) [catalina.jar:7.0.77]
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1182) [catalina.jar:7.0.77]
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1072) [catalina.jar:7.0.77]
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5368) [catalina.jar:7.0.77]
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5660) [catalina.jar:7.0.77]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145) [catalina.jar:7.0.77]
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:899) [catalina.jar:7.0.77]
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:875) [catalina.jar:7.0.77]
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652) [catalina.jar:7.0.77]
    at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1260) [catalina.jar:7.0.77]
    at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:2002) [catalina.jar:7.0.77]
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) [na:1.7.0_80]
    at java.util.concurrent.FutureTask.run(FutureTask.java:262) [na:1.7.0_80]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [na:1.7.0_80]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [na:1.7.0_80]
    at java.lang.Thread.run(Thread.java:745) [na:1.7.0_80]
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.xxx.service.ILoginService com.xxx.controller.LoginController.loginService; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.xxx.service.ILoginService] 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)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:558) ~[spring-beans-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87) ~[spring-beans-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331) ~[spring-beans-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    ... 33 common frames omitted
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.xxx.service.ILoginService] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1308) ~[spring-beans-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1054) ~[spring-beans-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:949) ~[spring-beans-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:530) ~[spring-beans-4.1.3.RELEASE.jar:4.1.3.RELEASE]
    ... 35 common frames omitted

出現這個異常一般有兩種情況，
1.沒有掃描到@Service註解，
2.掃描到了沒有寫@Service，

所以解決辦法就是檢視配置檔案掃描註解那裡是否掃描到了報錯的service，檢視一下報錯的service的實現類是否寫了@Service註解