如何使用注释在Spring中按名称自动装配？

Question

我有几个定义相同类的bean:

  @Bean
  public FieldDescriptor fullSpotField() {
     FieldDescriptor ans = new FieldDescriptor("full_spot", String.class);
     return ans;
  }

  @Bean
  public FieldDescriptor annotationIdField() {
     FieldDescriptor ans = new FieldDescriptor("annotationID", Integer.class);
     return ans;
  }

因此,当我自动给他们

   @Autowired
   public FieldDescriptor fullSpotField;

   @Autowired
   public FieldDescriptor annotationIdField;

我得到一个例外

NoUniqueBeanDefinitionException: No qualifying bean of type [...FieldDescriptor] is defined: expected single matching bean but found ...

如何在XML配置中按名称自动装配？

Answer 1

你可以@Qualifier用来解决它.

在您的情况下,您可以:

 @Bean(name="fullSpot")
 // Not mandatory. If not specified, it takes the method name i.e., "fullSpotField" as qualifier name.
  public FieldDescriptor fullSpotField() {
     FieldDescriptor ans = new FieldDescriptor("full_spot", String.class);
     return ans;
  }

  @Bean("annotationIdSpot")
  // Same as above comment.
  public FieldDescriptor annotationIdField() {
     FieldDescriptor ans = new FieldDescriptor("annotationID", Integer.class);
     return ans;
  }

然后您可以使用以下注入:

   @Autowired
   @Qualifier("fullSpot")
   public FieldDescriptor fullSpotField;

   @Autowired
   @Qualifier("annotationIdSpot")
   public FieldDescriptor annotationIdField;