@Produces @Named 给出了 WELD-001408

Question

我正在努力了解 CDI，在这种情况下，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");
}

}

为什么我得到

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

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 classes，因此它不知道 EntityProducer class。所以你必须手动添加你想要被CDI扫描的classes/packages。

您可以使用 @AdditionalClasses 注释：

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

}

编辑

然后你得到了一个不明确的依赖关系，因为你没有正确地限定你的注入。你应该在测试中使用 @Named("this") 或 @Named("that") class :

@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

@Produces @Named 给出了 WELD-001408

@Produces @Named gives a WELD-001408

java

cdi

weld