SpringBoot构造器注入循环依赖及解决方案

/**
 * @Author: lixs
 * @Date: 2021/4/6
 * @Description: 循环依赖类A
 */
@Component
public class CircularDependencyA {


    private CircularDependencyB circB;

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

/**
 1. @Author: lixs
 2. @Date: 2021/4/6
 3. @Description: 循环依赖类B
 */
@Component
public class CircularDependencyB {

    private CircularDependencyA circA;

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

/**
 1. @Author: lixs
 2. @Date: 2021/4/6
 3. @Description: 配置类
 */
@Configuration
@ComponentScan(basePackages = { "com.li.springboot.bean" })
public class TestConfig {
}

@SpringBootTest
@ContextConfiguration(classes = {TestConfig.class})
class ApplicationTests {

    @Test
    public void givenCircularDependency_whenConstructorInjection_thenItFails() {
        // Empty test; we just want the context to load
    }
}

/**
 * @Author: lixs
 * @Date: 2021/4/6
 * @Description: 循环依赖类A
 */
@Component
public class CircularDependencyA {

    private CircularDependencyB circB;

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

@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;
    }
}

@SpringBootTest
@ContextConfiguration(classes = {TestConfig.class})
class ApplicationTests {

     @Autowired
    ApplicationContext context;    //spring容器对象
 
    @Bean
    public CircularDependencyA getCircularDependencyA() {
        return new CircularDependencyA();
    }
 
    @Bean
    public CircularDependencyB getCircularDependencyB() {
        return new CircularDependencyB();
    }
 
    @Test
    public void testCircularDependency() {
    	//拿到bean对象
        CircularDependencyA circA = context.getBean(CircularDependencyA.class);
        //获取属性值
        String result=circA.getCircB().getMessage();
        System.out.println(result);
    }

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

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

@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;
    }
}