java - 带有限定符 @Default 的类型 ZZZZ 的不满足依赖关系

Question

我有 bean，如下所示。

@Singleton
@DependsOn("DefaultEmailService")
public class CustomerService implements UserHandlingService {

    private DefaultEmailService mailService;

    @Inject
    public CustomerService(DefaultEmailService mailService) {       
        this.mailService = mailService;
    }
}


@Singleton
@Startup
public class DefaultEmailService implements EmailService {

    public DefaultEmailService() {  
    }
}

我得到类似这样的错误

Caused by: org.jboss.weld.exceptions.DeploymentException: WELD-001408: Unsatisfied dependencies for type DefaultEmailService with qualifiers @Default
  at injection point [BackedAnnotatedParameter] Parameter 1 of [BackedAnnotatedConstructor] @Inject public com.project.service.CustomerService(DefaultEmailService)
  at com.project.service.CustomerService.<init>(CustomerService.java:0)

我做错了什么吗？

Answer 1

问题出在 @Singleton 注释，它来自 javax.ejb 而不是 javax.inject。使用 ejb 并定义接口(interface)，您的 bean 在 CDI 上下文中注册为接口(interface)，而不是实现，更改您的代码:

@Inject
public CustomerService(EmailService mailService) {
    this.mailService = (DefaultEmailService) mailService;
}