Question

我有以下界面

public interface IMyMapper<T> {}

和实施

public class MyMapper implements IMyMapper<MyClazz> {}

现在我想将类MyMapper注入无状态bean：

@Stateless
public class MyService {

    @Inject
    MyMapper mapper; //<-- does not work

    @Inject
    IMyMapper<MyClazz> mapper; //<-- also does not work
}

我的问题是注射不起作用。我得到一个例外：

org.jboss.weld.exceptions.DeploymentException: WELD-001408: Unsatisfied dependencies    for type MyMapper with qualifiers @Default
at injection point [BackedAnnotatedField] @Inject mypackage.MyService.mapper
at mypackage.MyService.mapper(MyService.java:0)

at org.jboss.weld.bootstrap.Validator.validateInjectionPointForDeploymentProblems(Validator.java:370)
at org.jboss.weld.bootstrap.Validator.validateInjectionPoint(Validator.java:291)
at org.jboss.weld.bootstrap.Validator.validateGeneralBean(Validator.java:134)
at org.jboss.weld.bootstrap.Validator.validateRIBean(Validator.java:165)
at org.jboss.weld.bootstrap.Validator.validateBean(Validator.java:529)
at org.jboss.weld.bootstrap.Validator.validateBeans(Validator.java:515)
at org.jboss.weld.bootstrap.Validator.validateDeployment(Validator.java:490)
at org.jboss.weld.bootstrap.WeldStartup.validateBeans(WeldStartup.java:419)
at org.jboss.weld.bootstrap.WeldBootstrap.validateBeans(WeldBootstrap.java:90)
at org.glassfish.weld.WeldDeployer.event(WeldDeployer.java:225)
at org.glassfish.kernel.event.EventsImpl.send(EventsImpl.java:131)
at org.glassfish.internal.data.ApplicationInfo.load(ApplicationInfo.java:328)
at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:496)
at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:219)
at org.glassfish.deployment.admin.DeployCommand.execute(DeployCommand.java:491)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$2$1.run(CommandRunnerImpl.java:539)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$2$1.run(CommandRunnerImpl.java:535)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:360)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$2.execute(CommandRunnerImpl.java:534)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$3.run(CommandRunnerImpl.java:565)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$3.run(CommandRunnerImpl.java:557)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:360)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:556)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:1464)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.access$1300(CommandRunnerImpl.java:109)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1846)
at org.glassfish.deployment.autodeploy.AutoOperation.run(AutoOperation.java:164)
at org.glassfish.deployment.autodeploy.AutoDeployer.deploy(AutoDeployer.java:597)
at org.glassfish.deployment.autodeploy.AutoDeployer.deployAll(AutoDeployer.java:484)
at org.glassfish.deployment.autodeploy.AutoDeployer.run(AutoDeployer.java:412)
at org.glassfish.deployment.autodeploy.AutoDeployer.run(AutoDeployer.java:403)
at org.glassfish.deployment.autodeploy.AutoDeployService$1.run(AutoDeployService.java:233)
at java.util.TimerThread.mainLoop(Timer.java:555)
at java.util.TimerThread.run(Timer.java:505)
]]

我该如何解决这个问题？

Answer 1

您可能处于annotated bean发现模式（the default mode in CDI 1.1+），这就是为什么您的类MyMapper不被视为bean类的原因。在这种模式下，要发现bean类应该有一个bean defining annotation。 @Stateless是一个定义注释的bean，所以你的EJB也是一个CDI bean，但它的注入点不能满足，因为MyMapper没有被发现是一个bean类。

要使代码正常工作，请尝试将@Dependent放在您的课程

上

@Dependent    
public class MyMapper implements IMyMapper<MyClazz> {}

或者，您可以将项目的发现模式更改为stated in the specification。

如何注入接口实现？

1 个答案: