springboot autowiring @Repository裏面的@Configuration不起作用

Question

我有一個簡單的彈簧啓動應用程序，其中我有一個jpa庫對象，我想在類似下面的@Configuration類中自動裝配。

@Configuration 
public class Appconfig { 

    @Bean 
    @Autowired 
    public PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer(OctopusPropertiesRepository repo) { 
     PropertySourcesPlaceholderConfigurer property = new PropertySourcesPlaceholderConfigurer(); 
     Map<String,Object> props = new ConcurrentHashMap<>(); 
     List<OctopusProperties> loadedSettings = repo.findAll(); 
     loadedSettings.forEach(entry -> props.put(entry.getKey(), entry.getValue())); 
     MutablePropertySources mutablePropertySources = new MutablePropertySources(); 
     mutablePropertySources.addFirst(new MapPropertySource("custom", props)); 
     property.setPropertySources(mutablePropertySources); 
     return property; 
    } 
} 

這裏是@Repository類

@Repository 
public interface OctopusPropertiesRepository extends JpaRepository<OctopusProperties, Long> { 
} 

，我得到以下異常。

Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.example.app.OctopusPropertiesRepository] 

如果我沒有使配置和啓動應用程序成功，我從執行器中看到bean是可用的。這裏有什麼問題？爲什麼我不能在@Configuration內部連線@Repository。

P.S.這兩個java文件位於同一文件夾下：com.example.app

P.P.S.我的項目 Eclipse視圖：

Answer 1

使用@PostConstruct。

@Autowired PropertySourcesPlaceholderConfigurer property; 


@Autowired OctopusPropertiesRepository repo; 


    @PostConstruct 
    public void onInit() { 

     Map<String,Object> props = new ConcurrentHashMap<>(); 
     List<OctopusProperties> loadedSettings = repo.findAll(); 
     loadedSettings.forEach(entry -> props.put(entry.getKey(), entry.getValue())); 
     MutablePropertySources mutablePropertySources = new MutablePropertySources(); 
     mutablePropertySources.addFirst(new MapPropertySource("custom", props)); 
     property.setPropertySources(mutablePropertySources); 

    } 

Answer 2

類似的問題在this問題

討論是否允許更改AppConfig類這樣的嗎？

@Configuration 
public class Appconfig { 

    @Autowired 
    private OctopusPropertiesRepository repo; 

    @Bean 
    public PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() { 
     PropertySourcesPlaceholderConfigurer property = new PropertySourcesPlaceholderConfigurer(); 
     Map<String,Object> props = new ConcurrentHashMap<>(); 
     List<OctopusProperties> loadedSettings = repo.findAll(); 
     loadedSettings.forEach(entry -> props.put(entry.getKey(), entry.getValue())); 
     MutablePropertySources mutablePropertySources = new MutablePropertySources(); 
     mutablePropertySources.addFirst(new MapPropertySource("custom", props)); 
     property.setPropertySources(mutablePropertySources); 
     return property; 
    } 
} 

如果此解決方案工作與否，還可以恢復。

Answer 3

按照@Bean的javadoc：

BeanFactoryPostProcessor-returning @Bean methods 
Special consideration must be taken for @Bean methods that return Spring 
BeanFactoryPostProcessor (BFPP) types. Because BFPP objects must be  
instantiated very early in the container lifecycle, they can interfere with 
processing of annotations such as @Autowired, @Value, and @PostConstruct 
within @Configuration classes. To avoid these lifecycle issues, mark BFPP 
returning @Bean methods as static. For example: 

@Bean 
public static PropertyPlaceholderConfigurer ppc() { 
    // instantiate, configure and return ppc ... 
} 


By marking this method as static, it can be invoked without causing 
instantiation of its declaring @Configuration class, thus avoiding the above- 
mentioned lifecycle conflicts. Note however that static @Bean methods will not 
be enhanced for scoping and AOP semantics as mentioned above. This works out 
in BFPP cases, as they are not typically referenced by other @Bean methods. As 
a reminder, a WARN-level log message will be issued for any non-static @Bean 
methods having a return type assignable to BeanFactoryPostProcessor. 

所以根據這一點，你應該propertySourcesPlaceholderConfigurer()是靜態的。

編輯： 對不起，後期編輯。 我不認爲你可以在這裏使用Hibernate倉庫，因爲BeanFactoryPostProcessor在hibernate和jpa需要任何依賴之前得到實例化。 也許你可以在這裏使用的JdbcTemplate，至少爲我工作：

@Configuration 
public class Appconfig { 

    @Bean 
    public PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() { 
     PropertySourcesPlaceholderConfigurer property = new PropertySourcesPlaceholderConfigurer(); 
     Map<String, Object> props = new ConcurrentHashMap<>(); 
     List<OctopusProperties> loadedSettings = getAll(); 
     loadedSettings.forEach(entry -> props.put(entry.getKey(), entry.getValue())); 
     MutablePropertySources mutablePropertySources = new MutablePropertySources(); 
     mutablePropertySources.addFirst(new MapPropertySource("custom", props)); 
     property.setPropertySources(mutablePropertySources); 
     return property; 
    } 

    @Bean 
    public static DataSource dataSource() { 
     DriverManagerDataSource dataSource = new DriverManagerDataSource(); 
     dataSource.setDriverClassName("com.mysql.jdbc.Driver"); 
     dataSource.setUrl("jdbc:mysql://localhost:3306/test"); 
     dataSource.setUsername("root"); 
     dataSource.setPassword("root"); 

     return dataSource; 
    } 

    private List<OctopusProperties> getAll() { 
     JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource()); 
     List<OctopusProperties> all = jdbcTemplate.query("select id,key_column,value_column from octopus_properties", 
       new RowMapper<OctopusProperties>() { 
        @Override 
        public OctopusProperties mapRow(final ResultSet rs, final int rowNum) throws SQLException { 
         OctopusProperties op = new OctopusProperties(); 
         op.setId(rs.getLong("id")); 
         op.setKey(rs.getString("key_column")); 
         op.setValue(rs.getString("value_column")); 
         return op; 
        } 
       }); 
     return all; 
    } 

} 

請注意，我用的MySQL在這裏，所以數據源被相應地配置。