spring如何动态指定具体实现类

// 接口public interface ServiceInterface {  public void method();} // 具体两个实现类@Service("aService")public class AServiceImpl implements ServiceInterface {   @Override  public void method() {    System.out.println("the impl is A");  }   @Override  public String toString() {    return "A";  }} @Service("bService")public class BServiceImpl implements ServiceInterface {   @Override  public void method() {    System.out.println("the impl is B");  }     @Override  public String toString() {    return "B";  } }

@Service("register")public class Register implements InitializingBean, ApplicationContextAware {  private Map<String, ServiceInterface> serviceImplMap = new HashMap<>();  private ApplicationContext applicationContext;   // 获取spring的上下文  @Override  public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {    this.applicationContext = applicationContext;  }   // 获取接口实现类的所有bean，并按自己定的规则放入map中  @Override  public void afterPropertiesSet() throws Exception {    Map<String, ServiceInterface> beanMap = applicationContext.getBeansOfType(ServiceInterface.class);    // 以下代码是将bean按照自己定的规则放入map中，这里我的规则是key：service.toString();value:bean    // 调用时，参数传入service.toString()的具体字符串就能获取到相应的bean    // 此处也可以不做以下的操作，直接使用beanMap,在调用时，传入bean的名称    for (ServiceInterface serviceImpl : beanMap.values()) {      serviceImplMap.put(serviceImpl.toString(), serviceImpl);    }  }     public ServiceInterface getServiceImpl(String name) {    return serviceImplMap.get(name);  } }

@ResourceRegister register; @Testpublic void testService() {  ServiceInterface service = register.getServiceImpl("A");  service.method();  ServiceInterface service2 = register.getServiceImpl("B");  service2.method();}

@Component("informerRegistry")public final class InformerRegistry implements ApplicationContextAware{   private ApplicationContext applicationContext;   @Override  public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {    this.applicationContext = applicationContext;  }}