我有一个使用Singleton模式的CommandService类，因此它有一个私有构造函数。在使用AOP之前，我使用getInstance()方法返回Application.java中的bean，如下所示：
@Configuration
@EnableAutoConfiguration
@ComponentScan({"hello","wodinow.weixin.jaskey"})
public class Application {
public static void main(String[] args) {
ApplicationContext ctx = SpringApplication.run(Application.class, args);
LogUtil.info("Beans provided by Spring Boot:");
String[] beanNames = ctx.getBeanDefinitionNames();
Arrays.sort(beanNames);
for (String beanName : beanNames) {
LogUtil.info(beanName);
}
LogUtil.info("Application Boots completes!");
}
//here I use a getInstance() to return that bean
@Bean
public CommandService commandService(){
return CommandService.getInstance();
}
我的Controller使用此类，需要Spring自动连接它。
@Controller
public class CoreController {
@Autowired
private CommandService commandService;
...
}
在我介绍AOP之前，这很好用。
在我使用这样的东西之后：
@Aspect
@Component
public class LogAspect {
@Pointcut("execution(* wodinow.weixin.jaskey..*.*(..))")
private void debug_log(){};
@AfterReturning("debug_log()")
public void debug(JoinPoint joinPoint){
LogUtil.debug("returns from "+joinPoint.getSignature());
}
}
运行Application.java时，我的应用程序失败
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'coreController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private wodinow.weixin.jaskey.service.CommandService wodinow.weixin.jaskey.co.CoreController.commandService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'commandService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private wodinow.weixin.jaskey.service.RoomService wodinow.weixin.jaskey.service.CommandService.roomService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'roomService' defined in class wodinow.weixin.jaskey.config.Application: Initialization of bean failed; nested exception is org.springframework.aop.framework.AopConfigException: Could not generate CGLIB subclass of class [class wodinow.weixin.jaskey.service.RoomService]: Common causes of this problem include using a final class or a non-visible class; nested exception is java.lang.IllegalArgumentException: No visible constructors in class wodinow.weixin.jaskey.service.RoomService
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:334)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1204)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:538)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:229)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:725)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480)
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:109)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:691)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:320)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:952)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:941)
at wodinow.weixin.jaskey.config.Application.main(Application.java:22)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private wodinow.weixin.jaskey.service.CommandService wodinow.weixin.jaskey.co.CoreController.commandService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'commandService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private wodinow.weixin.jaskey.service.RoomService wodinow.weixin.jaskey.service.CommandService.roomService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'roomService' defined in class wodinow.weixin.jaskey.config.Application: Initialization of bean failed; nested exception is org.springframework.aop.framework.AopConfigException: Could not generate CGLIB subclass of class [class wodinow.weixin.jaskey.service.RoomService]: Common causes of this problem include using a final class or a non-visible class; nested exception is java.lang.IllegalArgumentException: No visible constructors in class wodinow.weixin.jaskey.service.RoomService
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:555)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331)
... 16 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'commandService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private wodinow.weixin.jaskey.service.RoomService wodinow.weixin.jaskey.service.CommandService.roomService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'roomService' defined in class wodinow.weixin.jaskey.config.Application: Initialization of bean failed; nested exception is org.springframework.aop.framework.AopConfigException: Could not generate CGLIB subclass of class [class wodinow.weixin.jaskey.service.RoomService]: Common causes of this problem include using a final class or a non-visible class; nested exception is java.lang.IllegalArgumentException: No visible constructors in class wodinow.weixin.jaskey.service.RoomService
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:334)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1204)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:538)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:229)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1081)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1006)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:904)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:527)
... 18 more
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private wodinow.weixin.jaskey.service.RoomService wodinow.weixin.jaskey.service.CommandService.roomService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'roomService' defined in class wodinow.weixin.jaskey.config.Application: Initialization of bean failed; nested exception is org.springframework.aop.framework.AopConfigException: Could not generate CGLIB subclass of class [class wodinow.weixin.jaskey.service.RoomService]: Common causes of this problem include using a final class or a non-visible class; nested exception is java.lang.IllegalArgumentException: No visible constructors in class wodinow.weixin.jaskey.service.RoomService
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:555)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331)
... 29 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'roomService' defined in class wodinow.weixin.jaskey.config.Application: Initialization of bean failed; nested exception is org.springframework.aop.framework.AopConfigException: Could not generate CGLIB subclass of class [class wodinow.weixin.jaskey.service.RoomService]: Common causes of this problem include using a final class or a non-visible class; nested exception is java.lang.IllegalArgumentException: No visible constructors in class wodinow.weixin.jaskey.service.RoomService
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:548)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:229)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1081)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1006)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:904)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:527)
... 31 more
Caused by: org.springframework.aop.framework.AopConfigException: Could not generate CGLIB subclass of class [class wodinow.weixin.jaskey.service.RoomService]: Common causes of this problem include using a final class or a non-visible class; nested exception is java.lang.IllegalArgumentException: No visible constructors in class wodinow.weixin.jaskey.service.RoomService
at org.springframework.aop.framework.CglibAopProxy.getProxy(CglibAopProxy.java:212)
at org.springframework.aop.framework.ProxyFactory.getProxy(ProxyFactory.java:109)
at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.createProxy(AbstractAutoProxyCreator.java:445)
at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.wrapIfNecessary(AbstractAutoProxyCreator.java:331)
at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.postProcessAfterInitialization(AbstractAutoProxyCreator.java:291)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsAfterInitialization(AbstractAutowireCapableBeanFactory.java:422)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1573)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:540)
... 40 more
Caused by: java.lang.IllegalArgumentException: No visible constructors in class wodinow.weixin.jaskey.service.RoomService
at org.springframework.cglib.proxy.Enhancer.filterConstructors(Enhancer.java:531)
at org.springframework.cglib.proxy.Enhancer.generateClass(Enhancer.java:448)
at org.springframework.cglib.transform.TransformingClassGenerator.generateClass(TransformingClassGenerator.java:33)
at org.springframework.cglib.core.DefaultGeneratorStrategy.generate(DefaultGeneratorStrategy.java:25)
at org.springframework.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:216)
at org.springframework.cglib.proxy.Enhancer.createHelper(Enhancer.java:377)
at org.springframework.cglib.proxy.Enhancer.createClass(Enhancer.java:317)
at org.springframework.aop.framework.ObjenesisCglibAopProxy.createProxyClassAndInstance(ObjenesisCglibAopProxy.java:57)
at org.springframework.aop.framework.CglibAopProxy.getProxy(CglibAopProxy.java:202)
... 47 more
我的CommandService就像：
public class CommandService {
private static CommandService instance = new CommandService();
@Autowired
private RoomService roomService;//this is a class uses the same singleton patterns as `CommandService` does, and it has the same problem.
//private constructor
public CommandService() {}
// singleton patterns
public static CommandService getInstance() {
return instance;
}
...something else
}
我知道spring默认情况下每次只需要返回一个实例，但是如果我确实需要构造函数是私有的，以防其他人使用该构造函数。
谢谢！