@Produces @Named 给出了 WELD-001408

Question

我试图了解 CDI，在本例中是注释 @Produces 和 @Named

我有以下代码

@RunWith(CdiRunner.class)
public class cdiTest {

@Inject
protected CDIModel em;

@Test
public void injectionTest(){
    Assert.assertEquals("this", em.getMyString());
}

}

public class CDIModel {

String myString;

public CDIModel(String myString) {
    this.myString = myString;
}

public String getMyString() {
    return myString;
}
}

public class EntityProducer {

@Produces
@Named("this")
@Singleton
public CDIModel doThis() {
    return new CDIModel("this");
}

@Produces
@Named("that")
@Singleton
public CDIModel doThat() {
    return new CDIModel("that");
}

}

我为什么会得到

org.jboss.weld.exceptions.DeploymentException: WELD-001408: Unsatisfied 
dependencies for type CDIModel with qualifiers @Named
  at injection point [UnbackedAnnotatedField] @Inject @Named protected 
persistence.dao.cdiTest.em
  at persistence.dao.cdiTest.em(cdiTest.java:0)

添加@AdditionalClasses(EntityProducer.class) 后我得到了

org.jboss.weld.exceptions.DeploymentException: WELD-001409: Ambiguous 
dependencies for type CDIModel with qualifiers @Default
at injection point [UnbackedAnnotatedField] @Inject protected 
dk.nykredit.lanc.persistence.dao.cdiTest.em
at dk.nykredit.lanc.persistence.dao.cdiTest.em(cdiTest.java:0)
Possible dependencies: 
- Producer Method [CDIModel] with qualifiers [@Default @Named @Any] declared 
as [[BackedAnnotatedMethod] @Produces @Named @Singleton public 
persistence.dao.EntityProducer.doThat()],
- Producer Method [CDIModel] with qualifiers [@Default @Named @Any] declared 
as [[BackedAnnotatedMethod] @Produces @Named @Singleton public 
persistence.dao.EntityProducer.doThis()]

Answer 1

CDI-Unit 不会扫描所有类，因此它不知道 EntityProducer 类。因此，您必须手动添加要被 CDI 扫描的类/包。

你可以使用@AdditionalClasses注解：

@RunWith(CdiRunner.class)
@AdditionalClasses(EntityProducer.class)
public class cdiTest {
    ....
    ....

}

编辑

然后你得到一个模棱两可的依赖，因为你没有正确地限定你的注入。您应该在测试类中使用@Named("this") 或@Named("that")：

@Inject
@Named("this") // or @Named("that")
protected CDIModel em;

另请注意，在 CDI 中，我们通常使用 @Qualifier 而不是 @Named