Spring Boot无法启动 - bean之间存在循环依赖关系

Question

我使用配置类创建了Spring Boot应用程序.通常使用Spring库的RestAPI.在其中我使用我自己的Logger类来记录每个动作.

另外,我在我的Application类中包含application.properties,其中是main函数.xml中没有bean - 仅在该Configuration类中的所有内容.

这是配置:

@SpringBootConfiguration
public class ApplicationConfiguration {

@Value("${hibernate.dialect}")
private String dialect;
@Value("${hibernate.show_sql}")
private String showSql;
@Value("${hibernate.mappingResources}")
private String[] mappingResources;
@Value("${jdbc.driverClassName}")
private String driverClassName;
@Value("${jdbc.url}")
private String url;
@Value("${jdbc.username}")
private String username;
@Value("${jdbc.password}")
private String password;

@Autowired
private DataSource dataSource;
@Autowired
private LocalSessionFactoryBean localSessionFactoryBean;

@Bean
public LocalSessionFactoryBean localSessionFactoryBean() {
    LocalSessionFactoryBean sessionFactoryBean = new LocalSessionFactoryBean();
    sessionFactoryBean.setDataSource(dataSource);
    Properties hibernateProperties = new Properties();
    hibernateProperties.setProperty("hibernate.dialect", dialect);
    hibernateProperties.setProperty("hibernate.show_sql", showSql);
    sessionFactoryBean.setHibernateProperties(hibernateProperties);
    sessionFactoryBean.setMappingResources(mappingResources);
    return sessionFactoryBean;
}

@Bean
public DataSource dataSource() {
    DriverManagerDataSource dataSource = new DriverManagerDataSource();
    dataSource.setDriverClassName(driverClassName);
    dataSource.setUrl(url);
    dataSource.setUsername(username);
    dataSource.setPassword(password);
    return dataSource;
}

}

另外,我创建了logger类:

@Service
public class LinksLogger {

private static final Logger logger = Logger.getLogger("MyLogs");

// methods here...

}

这是我如何使用我的记录器:

@RestController
@RequestMapping("/api/v1")
public class HelloController {

@Autowired
private LinksLogger logger;

@RequestMapping(value = "/hello", method = RequestMethod.GET)
public Map<String, String> hello() {
    Map<String, String> data = new HashMap<>();
    data.put("data", "Hello#_#World");
    logger.log("Hello#_#World");
    return data;
}
}

看起来像okey,对吧？但是当我编译我的代码时,我得到了异常:

There is a circular dependency between 2 beans in the application context:
- helloController (field private com.defaultxyz.linksapi.util.LinksLogger com.defaultxyz.linksapi.controller.HelloController.logger)
- applicationConfiguration (field private org.springframework.orm.hibernate3.LocalSessionFactoryBean com.defaultxyz.linksapi.util.ApplicationConfiguration.localSessionFactoryBean)
- localSessionFactoryBean

为什么会出现此异常？我在代码中做错了什么？

Answer 1

您正在尝试在实例化的类中@Autowire bean.

@Autowired
private DataSource dataSource;
@Autowired
private LocalSessionFactoryBean localSessionFactoryBean;

但是你也将它们定义为@Bean,容器不能将它们注入到自动装配的字段中,因为它们是在同一个类中创建的.删除@Autowired字段,而是使用所需的方法.

sessionFactoryBean.setDataSource(dataSource());

代替

sessionFactoryBean.setDataSource(dataSource);