Spring循環依賴報錯Bean with name '**' has been injected into other beans [**] in its raw version as part

異常詳情

Bean with name ‘commonService’ has been injected into other beans [] 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 ‘getBeanNamesOfType’ with the ‘allowEagerInit’ flag turned off, for example.**

springboot循環依賴解決

1. 循環依賴是什么？

Bean A 依賴 B，Bean B 依賴 A這種情況下出現循環依賴。
Bean A → Bean B → Bean A
更復雜的間接依賴造成的循環依賴如下。
Bean A → Bean B → Bean C → Bean D → Bean E → Bean A

2. 循環依賴會產生什么結果？

當Spring正在加載所有Bean時，Spring嘗試以能正常創建Bean的順序去創建Bean。
例如，有如下依賴:
Bean A → Bean B → Bean C
Spring先創建beanC，接着創建bean B（將C注入B中)，最后創建bean A(將B注入A中)。

但當存在循環依賴時，Spring將無法決定先創建哪個bean。這種情況下，Spring將產生異常BeanCurrentlyInCreationException。

3.普通注入之間的循環依賴

比如：我現在有一個ServiceA需要調用ServiceB的方法，那么ServiceA就依賴於ServiceB，那在ServiceB中再調用ServiceA的方法，就形成了循環依賴。Spring在初始化bean的時候就不知道先初始化哪個，bean就會報錯。

public class ClassA { @Autowired ClassB classB; } 

public class ClassB { @Autowired ClassA classA } 

解決辦法:

如何解決循環依賴，最好的方法是重構代碼，進行解耦，如果沒有時間重構，可以使用下面的方法：

（1）在你的配置文件中，在互相依賴的兩個bean的任意一個加上lazy-init屬性

<bean id="ServiceDependent1" class="org.xyz.ServiceDependent1" lazy-init="true"> <constructor-arg ref="Service"/> </bean> <bean id="ServiceDependent2" class="org.xyz.ServiceDependent2" lazy-init="true"> <constructor-arg ref="Service"/> </bean> 

（2）在你注入bean時，在互相依賴的兩個bean上加上@Lazy注解也可以

@Autowired @Lazy private ClassA classA; @Autowired @Lazy private ClassB classB; 

構造器注入循環依賴實例

首先定義兩個相互通過構造器注入依賴的bean。

@Component public class CircularDependencyA { private CircularDependencyB circB; @Autowired public CircularDependencyA(CircularDependencyB circB) { this.circB = circB; } } 

@Component public class CircularDependencyB { private CircularDependencyA circA; @Autowired public CircularDependencyB(CircularDependencyA circA) { this.circA = circA; } } 

@Configuration @ComponentScan(basePackages = { "com.baeldung.circulardependency" }) public class TestConfig { } 

@RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration(classes = { TestConfig.class }) public class CircularDependencyTest { @Test public void givenCircularDependency_whenConstructorInjection_thenItFails() { // Empty test; we just want the context to load } } 

運行方法
givenCircularDependency_whenConstructorInjection_thenItFails
將會產生異常：BeanCurrentlyInCreationException: Error creating bean with name ‘circularDependencyA’:
Requested bean is currently in creation: Is there an unresolvable circular reference?

如何解決

（1）重新設計

重新設計結構，消除循環依賴。

（2）使用注解 @Lazy

一種最簡單的消除循環依賴的方式是通過延遲加載。在注入依賴時，先注入代理對象，當首次使用時再創建對象完成注入。

@Component public class CircularDependencyA { private CircularDependencyB circB; @Autowired public CircularDependencyA(@Lazy CircularDependencyB circB) { this.circB = circB; } } 

使用@Lazy后，運行代碼，可以看到異常消除。
（3）使用Setter/Field注入
Spring文檔建議的一種方式是使用setter注入。當依賴最終被使用時才進行注入。對前文的樣例代碼少做修改，來觀察測試效果。

@Component public class CircularDependencyA { private CircularDependencyB circB; @Autowired public void setCircB(CircularDependencyB circB) { this.circB = circB; } public CircularDependencyB getCircB() { return circB; } } 

@Component public class CircularDependencyB { private CircularDependencyA circA; private String message = "Hi!"; @Autowired public void setCircA(CircularDependencyA circA) { this.circA = circA; } public String getMessage() { return message; } } 

@RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration(classes = { TestConfig.class }) public class CircularDependencyTest { @Autowired ApplicationContext context; @Bean public CircularDependencyA getCircularDependencyA() { return new CircularDependencyA(); } @Bean public CircularDependencyB getCircularDependencyB() { return new CircularDependencyB(); } @Test public void givenCircularDependency_whenSetterInjection_thenItWorks() { CircularDependencyA circA = context.getBean(CircularDependencyA.class); Assert.assertEquals("Hi!", circA.getCircB().getMessage()); } } 

（4） 使用@PostConstruct

@Component public class CircularDependencyA { @Autowired private CircularDependencyB circB; @PostConstruct public void init() { circB.setCircA(this); } public CircularDependencyB getCircB() { return circB; } } 

@Component public class CircularDependencyB { private CircularDependencyA circA; private String message = "Hi!"; public void setCircA(CircularDependencyA circA) { this.circA = circA; } public String getMessage() { return message; } 

（5）實現ApplicationContextAware與InitializingBean

@Component public class CircularDependencyA implements ApplicationContextAware, InitializingBean { private CircularDependencyB circB; private ApplicationContext context; public CircularDependencyB getCircB() { return circB; } @Override public void afterPropertiesSet() throws Exception { circB = context.getBean(CircularDependencyB.class); } @Override public void setApplicationContext(final ApplicationContext ctx) throws BeansException { context = ctx; } } 

@Component public class CircularDependencyB { private CircularDependencyA circA; private String message = "Hi!"; @Autowired public void setCircA(CircularDependencyA circA) { this.circA = circA; } public String getMessage() { return message; }