Spring循环依赖报错Bean with name '**' has been injected into other beans [**] in its raw version as part

异常详情

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循环依赖解决

1. 循环依赖是什么？

Bean A 依赖 B，Bean B 依赖 A这种情况下出现循环依赖。
Bean A → Bean B → Bean A
更复杂的间接依赖造成的循环依赖如下。
Bean A → Bean B → Bean C → Bean D → Bean E → Bean A

2. 循环依赖会产生什么结果？

当Spring正在加载所有Bean时，Spring尝试以能正常创建Bean的顺序去创建Bean。
例如，有如下依赖:
Bean A → Bean B → Bean C
Spring先创建beanC，接着创建bean B（将C注入B中)，最后创建bean A(将B注入A中)。

但当存在循环依赖时，Spring将无法决定先创建哪个bean。这种情况下，Spring将产生异常BeanCurrentlyInCreationException。

3.普通注入之间的循环依赖

比如：我现在有一个ServiceA需要调用ServiceB的方法，那么ServiceA就依赖于ServiceB，那在ServiceB中再调用ServiceA的方法，就形成了循环依赖。Spring在初始化bean的时候就不知道先初始化哪个，bean就会报错。

public class ClassA { 
   @Autowired
   ClassB classB; 
}

public class ClassB { 
    @Autowired 
    ClassA classA 
}

解决办法:

如何解决循环依赖，最好的方法是重构代码，进行解耦，如果没有时间重构，可以使用下面的方法：

（1）在你的配置文件中，在互相依赖的两个bean的任意一个加上lazy-init属性

<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时，在互相依赖的两个bean上加上@Lazy注解也可以

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

构造器注入循环依赖实例

首先定义两个相互通过构造器注入依赖的bean。

@Componentpublic
    class CircularDependencyA {
        private CircularDependencyB circB;

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

    @Componentpublic
    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
    }
}

运行方法
givenCircularDependency_whenConstructorInjection_thenItFails
将会产生异常：BeanCurrentlyInCreationException: Error creating bean with name ‘circularDependencyA’:
Requested bean is currently in creation: Is there an unresolvable circular reference?

如何解决

（1）重新设计

重新设计结构，消除循环依赖。

（2）使用注解 @Lazy

一种最简单的消除循环依赖的方式是通过延迟加载。在注入依赖时，先注入代理对象，当首次使用时再创建对象完成注入。

    @Componentpublic
    class CircularDependencyA {
        private CircularDependencyB circB;

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

使用@Lazy后，运行代码，可以看到异常消除。
（3）使用Setter/Field注入
Spring文档建议的一种方式是使用setter注入。当依赖最终被使用时才进行注入。对前文的样例代码少做修改，来观察测试效果。

    @Componentpublic
    class CircularDependencyA {
        private CircularDependencyB circB;

        @Autowired
        public void setCircB(CircularDependencyB circB) {
            this.circB = circB;
        }

        public CircularDependencyB getCircB() {
            return circB;
        }
    }

    @Componentpublic
    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

    @Componentpublic
    class CircularDependencyA {
        @Autowired
        private CircularDependencyB circB;

        @PostConstruct
        public void init() {
            circB.setCircA(this);
        }

        public CircularDependencyB getCircB() {
            return circB;
        }
    }

    @Componentpublic
    class CircularDependencyB {
        private CircularDependencyA circA;
        private String message = "Hi!";

        public void setCircA(CircularDependencyA circA) {
            this.circA = circA;
        }

        public String getMessage() {
            return message;
        }
    }

（5）实现ApplicationContextAware与InitializingBean

    @Componentpublic
    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;
        }
    }

    @Componentpublic
    class CircularDependencyB {
        private CircularDependencyA circA;
        private String message = "Hi!";

        @Autowired
        public void setCircA(CircularDependencyA circA) {
            this.circA = circA;
        }

        public String getMessage() {
            return message;
        }
    }