Like @Autowired List <Integer> in spring

Question

I have a configuration class as shown below:

@Configuration
public class ListConfiguration {
    @Bean
    public List<Integer> list() {
        List<Integer> ints = new ArrayList<>();
        ints.add(1);
        ints.add(2);
        ints.add(3);
        return ints;
    }

    @Bean
    public int number() {
        return 4;
    }
}

I also have a test class as shown below

@RunWith(SpringRunner.class)
@ContextConfiguration(classes = ListConfiguration.class)
public class ListTest {
    @Autowired
    List<Integer> ints;

    @Test
    public void print() {
        System.out.println(ints.size());
        System.out.println(ints);
    }
}

But the method of exit printis 1, and [4], why not 3, and [1,2,3]? Thank you so much for any help!

Answer 1

You have a bean type Integerand a bean type List<Integer>in the context of your application.

, bean, autowire, List<Integer>, . , Spring , AutowiredAnnotationBeanPostProcessor.

TL; DR , Spring :

• @Value
• beans .
• beans, .

, autwiring, List<Integer> Spring Integer beans , List<Integer> bean.

DefaultListableBeanFactory.

:

public Object doResolveDependency(DependencyDescriptor descriptor, String beanName,
        Set<String> autowiredBeanNames, TypeConverter typeConverter) throws BeansException {

    Class<?> type = descriptor.getDependencyType();
    //Searches for an @Value annotation and 
    Object value = getAutowireCandidateResolver().getSuggestedValue(descriptor);
    if (value != null) {
        //Handle finding, building and returning default value
    }
    /* 
     * Check for multiple beans of given type. Because a bean is returned here,
     * Spring autowires the Integer bean instance.
     */
    Object multipleBeans = resolveMultipleBeans(descriptor, beanName, autowiredBeanNames, typeConverter);
    if (multipleBeans != null) {
        return multipleBeans;
    }
    InjectionPoint previousInjectionPoint = ConstructorResolver.setCurrentInjectionPoint(descriptor);
    try {
        Map<String, Object> matchingBeans = findAutowireCandidates(beanName, type, descriptor);
        // Do more stuff here to try and narrow down to a single instance to autowire.
    }
}

, , @Qualifer , beans .

EDIT: , . bean . - @Value , Spring .

:

application.properties

list=1,2,3,4

bean:

@Bean 
public ConversionService conversionService() {
    return new DefaultConversionService();
}

, , , .

:

@Value("${list}")
private List<Integer> anotherList;

anotherList 1,2,3 4 .

Answer 2

Spring Integer beans List Autowiring List<Integer> bean, .

, @Qualifier("list") , , .