循环依赖解决
尽量不要使用循环依赖；
当无可避免要使用循环依赖时，禁止使用构造器注入依赖属性，使用注解（@Resource、@Autowired）属性
自循环依赖：属性注入
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pojo 层
Person
@Component public class Person { @Resource private Person person; public void print(){ System.out.println(this.person); } }
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controller 层
HelloController
@RestController public class HelloController { @Resource private Person person; @RequestMapping("/hello") public String hello(){ person.print(); return "success"; } }
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控制台输出
2020-07-03 18:20:11.260 INFO 13544 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Initializing Servlet 'dispatcherServlet' 2020-07-03 18:20:11.266 INFO 13544 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Completed initialization in 6 ms com.example.demo.pojo.Person@2b26c8e4
使用三级缓存，解决了属性注入自循环依赖
自循环依赖：构造器注入
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pojo 层
Person
@Component public class Person { private Person person; public Person(Person person){ this.person=person; } public void print(){ System.out.println(this.person); } }
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controller 层
HelloController
@RestController public class HelloController { @Resource private Person person; @RequestMapping("/hello") public String hello(){ person.print(); return "success"; } }
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控制台输出
2020-07-03 18:24:33.550 INFO 19416 --- [ main] o.apache.catalina.core.StandardService : Stopping service [Tomcat] 2020-07-03 18:24:33.668 INFO 19416 --- [ main] ConditionEvaluationReportLoggingListener : Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled. 2020-07-03 18:24:33.674 ERROR 19416 --- [ main] o.s.b.d.LoggingFailureAnalysisReporter : *************************** APPLICATION FAILED TO START *************************** Description: The dependencies of some of the beans in the application context form a cycle: helloController ┌─────┐ | person defined in file [E:\java\IdeaProjects\springboot 测试\target\classes\com\example\demo\pojo\Person.class] └─────┘
启动报错：存在自循环依赖，使用构造器创建person，person没有添加到缓存，不能提前暴露
自循环依赖：代理对象（@Transactional）
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service 层
HelloService
public interface HelloService { void hello(); }
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serviceImpl 层
HelloServiceImpl
@Service public class HelloServiceImpl implements HelloService { @Resource private HelloService helloService; @Override @Transactional public void hello() { System.out.println(helloService); System.out.println("hello world"); } }
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controller 层
HelloController
@RestController public class HelloController { @Resource private HelloService helloService; @RequestMapping("/hello") public String hello(){ helloService.hello(); return "success"; } }
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控制台输出
localhost:8080/hello
2020-07-03 19:09:09.017 INFO 3652 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring DispatcherServlet 'dispatcherServlet' 2020-07-03 19:09:09.017 INFO 3652 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Initializing Servlet 'dispatcherServlet' 2020-07-03 19:09:09.023 INFO 3652 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Completed initialization in 6 ms WARNING: An illegal reflective access operation has occurred WARNING: Illegal reflective access by org.springframework.cglib.core.ReflectUtils (file:/E:/Program Files/apache-maven-3.6.1-bin/apache-maven-3.6.1/repository/org/springframework/spring-core/5.2.7.RELEASE/spring-core-5.2.7.RELEASE.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain) WARNING: Please consider reporting this to the maintainers of org.springframework.cglib.core.ReflectUtils WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations WARNING: All illegal access operations will be denied in a future release com.example.demo.serviceImpl.HelloServiceImpl@4aa55ed8 hello world说明：事务Transactional可以提前暴露，可将代理对象提前注入到其他bean中
自循环依赖：代理对象（@Async）
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service 层
Hello3Service
@Service public class Hello3Service { @Resource private Hello3Service hello3Service; @Async public void test(){ hello3Service.test2(); System.out.println("hello3 service test"); } @Async public void test2(){ System.out.println("hello3 service test2"); } }
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config 层
WebConfig：开启异步功能
@EnableAsync @Configuration public class WebConfig { }
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controller 层
Hello2Controller
@RestController public class Hello2Controller { @Resource private Hello3Service hello3Service; @RequestMapping("/hello2") public String hello(){ hello3Service.test(); return "success"; } }
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控制台输出
2020-07-04 16:03:15.238 INFO 3036 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext 2020-07-04 16:03:15.238 INFO 3036 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1165 ms 2020-07-04 16:03:15.325 WARN 3036 --- [ main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hello2Controller': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'hello3Service': Bean with name 'hello3Service' has been injected into other beans [hello3Service] in its raw version as part of a circular reference, but has eventually been wrapped. This means that said other beans do not use the final version of the bean. This is often the result of over-eager type matching - consider using 'getBeanNamesForType' with the 'allowEagerInit' flag turned off, for example. 2020-07-04 16:03:15.329 INFO 3036 --- [ main] o.apache.catalina.core.StandardService : Stopping service [Tomcat] 2020-07-04 16:03:15.350 INFO 3036 --- [ main] ConditionEvaluationReportLoggingListener : Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled. 2020-07-04 16:03:15.369 ERROR 3036 --- [ main] o.s.boot.SpringApplication : Application run failed org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hello2Controller': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'hello3Service': Bean with name 'hello3Service' has been injected into other beans [hello3Service] in its raw version as part of a circular reference, but has eventually been wrapped. This means that said other beans do not use the final version of the bean. This is often the result of over-eager type matching - consider using 'getBeanNamesForType' with the 'allowEagerInit' flag turned off, for example. at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessProperties(CommonAnnotationBeanPostProcessor.java:321) ~[spring-context-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1422) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:594) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:893) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:879) ~[spring-context-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:551) ~[spring-context-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:750) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1237) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE] at com.example.demo.DemoApplication.main(DemoApplication.java:10) ~[classes/:na] Caused by: org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'hello3Service': Bean with name 'hello3Service' has been injected into other beans [hello3Service] in its raw version as part of a circular reference, but has eventually been wrapped. This means that said other beans do not use the final version of the bean. This is often the result of over-eager type matching - consider using 'getBeanNamesForType' with the 'allowEagerInit' flag turned off, for example. at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:624) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:207) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.resolveBeanByName(AbstractAutowireCapableBeanFactory.java:454) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.autowireResource(CommonAnnotationBeanPostProcessor.java:527) ~[spring-context-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.getResource(CommonAnnotationBeanPostProcessor.java:497) ~[spring-context-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor$ResourceElement.getResourceToInject(CommonAnnotationBeanPostProcessor.java:650) ~[spring-context-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.inject(InjectionMetadata.java:239) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:130) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessProperties(CommonAnnotationBeanPostProcessor.java:318) ~[spring-context-5.2.7.RELEASE.jar:5.2.7.RELEASE] ... 18 common frames omitted
启动报错：将未创建完成的对象注入到bean中，async不支持早期引用时创建代理对象
循环依赖：代理对象（@Async）
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service 层
HelloService
@Service public class HelloService { @Resource private Hello2Service hello2Service; @Async public void test(){ hello2Service.test2(); System.out.println("hello service test"); } @Async public void test2(){ System.out.println("hello service test2"); } }
Hello2Servcice
@Service public class Hello2Service { @Resource private HelloService helloService; @Async public void test(){ helloService.test2(); System.out.println("hello2 service test"); } @Async public void test2(){ System.out.println("hello2 service test2"); } }
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config 层
WebConfig：开启异步功能
@EnableAsync @Configuration public class WebConfig { }
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controller 层
HelloController
@RestController public class HelloController { @Resource private HelloService helloService; @Resource private Hello2Service hello2Service; @RequestMapping("/hello") public String hello(){ helloService.test(); hello2Service.test(); return "success"; } }
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控制台输出
2020-07-04 11:47:53.826 INFO 10168 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext 2020-07-04 11:47:53.826 INFO 10168 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 941 ms 2020-07-04 11:47:53.900 WARN 10168 --- [ main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'helloController': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'helloService': Bean with name 'helloService' has been injected into other beans [hello2Service] in its raw version as part of a circular reference, but has eventually been wrapped. This means that said other beans do not use the final version of the bean. This is often the result of over-eager type matching - consider using 'getBeanNamesForType' with the 'allowEagerInit' flag turned off, for example. 2020-07-04 11:47:53.903 INFO 10168 --- [ main] o.apache.catalina.core.StandardService : Stopping service [Tomcat] 2020-07-04 11:47:53.917 INFO 10168 --- [ main] ConditionEvaluationReportLoggingListener : Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled. 2020-07-04 11:47:53.931 ERROR 10168 --- [ main] o.s.boot.SpringApplication : Application run failed org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'helloController': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'helloService': Bean with name 'helloService' has been injected into other beans [hello2Service] in its raw version as part of a circular reference, but has eventually been wrapped. This means that said other beans do not use the final version of the bean. This is often the result of over-eager type matching - consider using 'getBeanNamesForType' with the 'allowEagerInit' flag turned off, for example. at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessProperties(CommonAnnotationBeanPostProcessor.java:321) ~[spring-context-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1422) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:594) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:893) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:879) ~[spring-context-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:551) ~[spring-context-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:750) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1237) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE] at com.example.demo.DemoApplication.main(DemoApplication.java:10) ~[classes/:na] Caused by: org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'helloService': Bean with name 'helloService' has been injected into other beans [hello2Service] in its raw version as part of a circular reference, but has eventually been wrapped. This means that said other beans do not use the final version of the bean. This is often the result of over-eager type matching - consider using 'getBeanNamesForType' with the 'allowEagerInit' flag turned off, for example. at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:624) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:207) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.resolveBeanByName(AbstractAutowireCapableBeanFactory.java:454) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.autowireResource(CommonAnnotationBeanPostProcessor.java:527) ~[spring-context-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.getResource(CommonAnnotationBeanPostProcessor.java:497) ~[spring-context-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor$ResourceElement.getResourceToInject(CommonAnnotationBeanPostProcessor.java:650) ~[spring-context-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.inject(InjectionMetadata.java:239) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:130) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE] at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessProperties(CommonAnnotationBeanPostProcessor.java:318) ~[spring-context-5.2.7.RELEASE.jar:5.2.7.RELEASE] ... 18 common frames omitted
启动报错：将未创建完成的对象当做代理对象注入，async不支持在获取早期引用的时候创建代理对象
原型（prototype）循环依赖
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pojo 层
A
@Scope("prototype") @Component public class A { @Resource private B b; public void print(){ System.out.println(b); } }
B
@Scope("prototype") @Component public class B { @Resource private A a; }
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controller 层
HelloController
@RestController public class HelloController { @Resource private A a; @RequestMapping("/hello") public String hello(){ a.print(); return "success"; } }
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控制台输出
localhost:8080/hello
2020-07-03 21:36:56.726 INFO 21076 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext 2020-07-03 21:36:56.726 INFO 21076 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1039 ms 2020-07-03 21:36:56.780 WARN 21076 --- [ main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'helloController': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'a': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'b': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'a': Requested bean is currently in creation: Is there an unresolvable circular reference? 2020-07-03 21:36:56.781 INFO 21076 --- [ main] o.apache.catalina.core.StandardService : Stopping service [Tomcat] 2020-07-03 21:36:56.795 INFO 21076 --- [ main] ConditionEvaluationReportLoggingListener : Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled. 2020-07-03 21:36:56.799 ERROR 21076 --- [ main] o.s.b.d.LoggingFailureAnalysisReporter : *************************** APPLICATION FAILED TO START *************************** Description: The dependencies of some of the beans in the application context form a cycle: helloController ┌─────┐ | a ↑ ↓ | b └─────┘prototype没有使用三级缓存，不能解决对象之间的循环依赖
