Question

我想基于属性文件动态创建多个相似的bean，以替换重复的代码。

这是个好主意吗？

我的原始重复代码：

@Configuration
@Order(Integer.MIN_VALUE)
public class HessianFactory {


    public static PubHessianServiceExporter createHessianService(Object service, Class clazz) {
        PubHessianServiceExporter exporter = new PubHessianServiceExporter();
        exporter.setService(service);
        exporter.setServiceInterface(clazz);
        return exporter;
    }

    @Bean("/svc/curriculumScheduleService/1")
    public PubHessianServiceExporter curriculumScheduleService1() {
        return HessianFactory.createHessianService(StudentAppServiceFactory.curriculumScheduleServices.get(1), CurriculumScheduleService.class);
    }

    @Bean("/svc/curriculumScheduleService/2")
    public PubHessianServiceExporter curriculumScheduleService2() {
        return HessianFactory.createHessianService(StudentAppServiceFactory.curriculumScheduleServices.get(2), CurriculumScheduleService.class);
    }

    @Bean("/svc/curriculumScheduleService/3")
    public PubHessianServiceExporter curriculumScheduleService3() {
        return HessianFactory.createHessianService(StudentAppServiceFactory.curriculumScheduleServices.get(3), CurriculumScheduleService.class);
    }

    @Bean("/svc/curriculumScheduleService/5")
    public PubHessianServiceExporter curriculumScheduleService5() {
        return HessianFactory.createHessianService(StudentAppServiceFactory.curriculumScheduleServices.get(5), CurriculumScheduleService.class);
    }
}

我尝试使用下面给出的代码：

@Configuration
@Order(Integer.MIN_VALUE)
public class HessianFactory {

    @Value("${sign-sys-ids}")
    private String[] signSysIds;
    @Autowired
    private ConfigurableBeanFactory beanFactory;


    public static HessianServiceExporter createHessianService(Object service, Class clazz) {
        HessianServiceExporter exporter = new HessianServiceExporter();
        exporter.setService(service);
        exporter.setServiceInterface(clazz);
        return exporter;
    }

    @PostConstruct
    public void init() throws BeansException {
        Arrays.stream(signSysIds).forEach(
            i -> {
                HessianServiceExporter hessianServiceExporter = createHessianService(
                    StudentAppServiceFactory.curriculumScheduleServices.get(Integer.parseInt(i)), CurriculumScheduleService.class);
                beanFactory.registerSingleton("/svc/curriculumScheduleService/" + i, hessianServiceExporter);
            }
        );
    }
}

但是上面的代码不起作用。

curriculumScheduleServices 是带有不同index(i)

的cademicScheduleService的地图

Answer 1

您可能在代码中的某处缺少了@DependsOn。由于您是以编程方式创建bean的，因此无法保证这些bean在应用程序上下文中何时可用。要强制执行命令，可以将@DependsOn添加到使用它的配置中。参见下面的示例

依赖于以编程方式创建bean的其他配置的配置

@Configuration
@DependsOn("TestConfiguration2")
public class TestConfiguration1 {

  @Autowired
  @Qualifier("/svc/curriculumScheduleService/1")
  private DummyClass dummyClass1;
  @Autowired
  @Qualifier("/svc/curriculumScheduleService/2")
  private DummyClass dummyClass2;
  @Autowired
  @Qualifier("/svc/curriculumScheduleService/3")
  private DummyClass dummyClass3;
  @Autowired
  @Qualifier("/svc/curriculumScheduleService/5")
  private DummyClass dummyClass5;

  @PostConstruct
  public void printBeans() {
    System.out.println(dummyClass1.getVal());
    System.out.println(dummyClass2.getVal());
    System.out.println(dummyClass3.getVal());
    System.out.println(dummyClass5.getVal());
  }
}

以编程方式创建bean的配置

@Configuration("TestConfiguration2")
public class TestConfiguration2 {

  @Autowired
  private ConfigurableBeanFactory beanFactory;

  @PostConstruct
  public void setup() {
    String[] array = {"1", "2", "3", "5"};
    Arrays.stream(array).map(Integer::parseInt).forEach(i -> {
      System.out.println("creating new bean");
      beanFactory.registerSingleton("/svc/curriculumScheduleService/" + i, new DummyClass(i));
    });
  }
}

Answer 2

@PostConstruct
public void init() throws BeansException {
    Arrays.stream(signSysIds).forEach(
        i -> {
            String beanName = "/svc/curriculumScheduleService/" + i;
            AbstractBeanDefinition bean = BeanDefinitionBuilder.genericBeanDefinition(PubHessianServiceExporter.class)
                .addPropertyValue("service", StudentAppServiceFactory.curriculumScheduleServices.get(Integer.parseInt(i)))
                .addPropertyValue("serviceInterface", CurriculumScheduleService.class)
                .getBeanDefinition();
            beanFactory.registerBeanDefinition(beanName, bean);
        }
    );
}

可以。

Spring：如何在Spring Boot中动态创建类似的bean？

2 个答案: