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在spring容器启动的过程中报如下错误： 2017-07-04 07:09:53.231 WARN [bi-service-recom-server,,,] 1 --- [ main] ationConfigEmbeddedWebApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'recomController': Unsatisfied dependency expressed through field 'recommService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'recommService': Unsatisfied dependency expressed through field 'personalizedABRouteTable'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'ABTestConf': Unsatisfied dependency expressed through field 'personalizedABRouteTable'; nested exception is org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'personalizedABRouteTable': Requested bean is currently in creation: Is there an unresolvable circular reference?
检查发现并没有循环依赖的bean，再查看一下最后一个错误信息的类：
@Component
public class MyClass {
@Autowired
PersonalizedABRouteTable personalizedABRouteTable;
@Bean("personalizedABRouteTable")
public PersonalizedABRouteTable getPersonalizedABRouteTable() {
PersonalizedABRouteTable table = new PersonalizedABRouteTable();
table.orderedRuleList = personalizedRouteRules;
return table;
}
}发现了问题所在。spring在类加载的时候，有两类方式获取bean，一是通过@autowired等标签注入装载到容器的bean；还有一种方式是使用@bean等标签通知spring容器生成一个指定的bean。
在这里PersonalizedABRouteTable并不在spring容器中初始化的时候生成，而是使用MyClass的@bean标签生成，之后注入到类中。
但是这两种方式尽量不要混用。在上述例子中只被初始化一次不会有问题，一旦另外一个类同样需要注入PersonalizedABRouteTable，则容器初始化bean的时候就会产生循环依赖，另外一个类一直在等待MyClass初始化生成PersonalizedABRouteTable，而MyClass又没有装载完成，因此产生了circle reference。
将@Autowired注释去掉后，问题解决。
从另外一个层面讲，将@bean注解去掉，使用@PostConstruct注解，通过applicationContext获取bean，交给MyClass后，同样不会循环依赖。原理是相通的。