Spring解决循环依赖（不讲原理）The dependencies of some of the beans in the application context form a cycle

Spring解决循环依赖（不讲原理）The dependencies of some of the beans in the application context form a cycle 循环依赖场景

有三个类：

@Service
public class AService {
    @Autowired
    private BService bService;
}

@Service
public class BService {
    @Autowired
    private CService cService;
}

@Service
public class CService {
    @Autowired
    private AService aService;
}

造成循环依赖报错：

The dependencies of some of the beans in the application context form a cycle:

┌─────┐
|  AService (field private com.example.demo.service.BService com.example.demo.service.AService.bService)
↑     ↓
|  BService (field private com.example.demo.service.CService com.example.demo.service.BService.cService)
↑     ↓
|  CService (field private com.example.demo.service.AService com.example.demo.service.CService.aService)
└─────┘

解决方案

对其中一个进行改造，例如对CService改造，采用如下注入方式：

@Service
public class CService {

    private AService aService; // 去掉@Autowired
    
	// 采用构造器方式，加入Lazy注解
    public CService(@Lazy AService aService) { 
        this.aService = aService;
    }
}