Question

我正在学习Java EE中的CDI和不同的注释。我创建了一个repo。我使用相同的托管bean来生成两个问候字符串。非正式和正式。我收到以下错误：

SEVERE:   Exception while loading the app : CDI deployment failure:WELD-001409 Ambiguous dependencies for type [String] with qualifiers [@Formal] at injection point [[BackedAnnotatedField] @Inject @Formal mypackage.HelloServlet.formalMessage]. Possible dependencies [[Producer Method [String] with qualifiers [@Formal @Any] declared as [[BackedAnnotatedMethod] @Produces @Formal public mypackage.ProduceFormalGreeting.GetFormalGreeting()], Producer Method [String] with qualifiers [@Formal @Any] declared as [[BackedAnnotatedMethod] @Produces @Formal public mypackage.ProduceGreeting.GetFormalGreeting()]]]
org.jboss.weld.exceptions.DeploymentException: WELD-001409 Ambiguous dependencies for type [String] with qualifiers [@Formal] at injection point [[BackedAnnotatedField] @Inject @Formal mypackage.HelloServlet.formalMessage]. Possible dependencies [[Producer Method [String] with qualifiers [@Formal @Any] declared as [[BackedAnnotatedMethod] @Produces @Formal public mypackage.ProduceFormalGreeting.GetFormalGreeting()], Producer Method [String] with qualifiers [@Formal @Any] declared as [[BackedAnnotatedMethod] @Produces @Formal public mypackage.ProduceGreeting.GetFormalGreeting()]]]
    at org.jboss.weld.bootstrap.Validator.validateInjectionPointForDeploymentProblems(Validator.java:406)

我不确定为什么当第一个函数用Formal注释而第二个函数用Informal注释时会有歧义。当我删除其中一个函数或将其移动到另一个bean类时，错误消失了。谢谢

public class ProduceGreeting {

    @Produces
    @Formal
    public String GetFormalGreeting(){
        return "Good morning !";
    }

    @Produces
    @InFormal
    public String GetInFormalGreeting(){
        return "Hi there !";
    }
}

调用ProduceGreeting类的Servlet：

@Inject
@Formal
String formalMessage;

@Inject
@InFormal
String informalMessage;
...
...

 out.println("<h2> Formal Greeting: " + formalMessage + "</h2>");
 out.println("<h2> Informal Greeting: " + informalMessage + "</h2>");

编辑 - 添加非正式和正式注释（也可在repo中找到）。

@Qualifier
@Retention(RUNTIME)
@Target({TYPE, METHOD, FIELD, PARAMETER})
public @interface Formal {}


@Qualifier
@Retention(RUNTIME)
@Target({TYPE, METHOD, FIELD, PARAMETER})
public @interface InFormal {}

Answer 1

错误消息显示您有

mypackage.ProduceFormalGreeting.GetFormalGreeting()

方法和

mypackage.ProduceGreeting.GetFormalGreeting()

也是。我想你需要在target目录中进行清理以删除旧类（它可能在开发期间被重命名）。（代码很好，它适用于Java SE。）

同一个bean中的两个生成器会导致Ambiguity错误

1 个答案: