目录

• 前言
• 处理方案一：
• 处理方案二：
• 处理方案三：
• 总结

前言

如下代码，ComponentA类注入ComponentB类，ComponentB类注入ComponentA类，就会发生循环依赖的问题，在2.6.0之前，spring会自动处理循环依赖的问题

import org.springframework.stereotype.Service;
import javax.annotation.Resource;
 
@Service
public class ComponentA {
 
    @Resource
    private ComponentB componentB;
 
}

import org.springframework.stereotype.Service;
import javax.annotation.Resource;
 
@Service
public class ComponentB {
 
    @Resource
    private ComponentA componentA;
 
}

现在，2.6.0 这个版本已经默认禁止 Bean 之间的循环引用，如果存在循环引用就会启动失败报错：

***************************
APPLICATION FAILED TO START
***************************

Description:

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

┌─────┐
|  componentA
↑     ↓
|  componentB
└─────┘

Action:

Relying upon circular references is discouraged and they are prohibited by default. Update your application to remove the dependency cycle between beans. As a last resort, it may be possible to break the cycle automatically by setting spring.main.allow-circular-references to true.

处理方案一：

 整改业务，清理掉所有存在循环引用的 Bean

处理方案二：

spring:
  main:
    allow-circular-references: true

处理方案三：

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
 
@SpringBootApplication
public class SpringDemoApplication {
 
    public static void main(String[] args) {
        SpringApplication application = new SpringApplication(SpringDemoApplication.class);
        application.setAllowCircularReferences(Boolean.TRUE);
        application.run(args);
    }
}

总结