java - 避免多项目环境中模糊依赖关系的众所周知的策略

Question

我设置了多个 Maven 项目，最终打包为 EAR 存档。这些项目的类型为 jar、ejb 或 war。

现在我有一个 javax.enterprise.context.SessionScoped CDI Bean，注释为javax.enterprise.inject.Default，携带有关当前用户的信息(主要从 Shiro-Framework 检索)。我还有两个自治的 Web 应用程序，它们应该使用这个 Bean，因此我将该 Bean 放在一个项目中，由两个项目引用

我现在的问题是，我在部署期间遇到异常，告诉我无法注入(inject) Bean，因为有两个可能的依赖项，引用完全相同的类。我猜想这是因为包含 Bean 的项目(Jar 项目)附加到两个 Web 项目，并且因此 Bean 被多次发现。

这是我的问题:是否有一个众所周知的策略来处理此类问题，或者有一些方法来向应用程序服务器/CDI 实现发出信号(在我的例子中，Glassfish 4.x 使用 Weld Framework)，以便只读取一次？

我确实注意到有可能使用javax.enterprise.inject.Instance，但我不想使用它，因为它对于应用程序允许变化的可能性至关重要当前操作用户的快照。我还考虑了通过 API 和实现项目提供这些 Bean 的方法，仅引用 API 作为依赖项，但这会产生巨大的开销，因为这些项目目前每个只包含一个类。

这是我的 Beans 类 header :

package omega1001.mediaserver.domainmodel.web;

import ...;


@SessionScoped
@Default
public class OmegaMediaServerSubject implements Serializable {

这就是我尝试注入(inject) Bean 的方式:

@Inject
    private OmegaMediaServerSubject subject;

这是我在部署时遇到的异常:

org.jboss.weld.exceptions.DeploymentException: WELD-001409: Ambiguous dependencies for type OmegaMediaServerSubject with qualifiers @Default
  at injection point [BackedAnnotatedField] @Inject private omega1001.mediaserver.servlet.messageProcessor.DefaultMessageProcessor.subject
  at omega1001.mediaserver.servlet.messageProcessor.DefaultMessageProcessor.subject(DefaultMessageProcessor.java:0)
  Possible dependencies: 
  - Managed Bean [class omega1001.mediaserver.domainmodel.web.OmegaMediaServerSubject] with qualifiers [@Default @Any],
  - Managed Bean [class omega1001.mediaserver.domainmodel.web.OmegaMediaServerSubject] with qualifiers [@Default @Any]
    at org.jboss.weld.bootstrap.Validator.validateInjectionPointForDeploymentProblems(Validator.java:367)
    at org.jboss.weld.bootstrap.Validator.validateInjectionPoint(Validator.java:281)
    at org.jboss.weld.bootstrap.Validator.validateGeneralBean(Validator.java:134)
    at org.jboss.weld.bootstrap.Validator.validateRIBean(Validator.java:155)
    at org.jboss.weld.bootstrap.Validator.validateBean(Validator.java:518)
    at org.jboss.weld.bootstrap.Validator.validateBeans(Validator.java:504)
    at org.jboss.weld.bootstrap.Validator.validateDeployment(Validator.java:479)
    at org.jboss.weld.bootstrap.WeldStartup.validateBeans(WeldStartup.java:443)
    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 com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1722)
    at org.glassfish.admin.rest.utils.ResourceUtil.runCommand(ResourceUtil.java:253)
    at org.glassfish.admin.rest.utils.ResourceUtil.runCommand(ResourceUtil.java:231)
    at org.glassfish.admin.rest.utils.ResourceUtil.runCommand(ResourceUtil.java:275)
    at org.glassfish.admin.rest.resources.TemplateListOfResource.createResource(TemplateListOfResource.java:133)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory$1.invoke(ResourceMethodInvocationHandlerFactory.java:81)
    at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:144)
    at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:161)
    at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$ResponseOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:160)
    at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:99)
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:389)
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:347)
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:102)
    at org.glassfish.jersey.server.ServerRuntime$2.run(ServerRuntime.java:309)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:271)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:267)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:315)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:297)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:267)
    at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:317)
    at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:292)
    at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:1139)
    at org.glassfish.jersey.grizzly2.httpserver.GrizzlyHttpContainer.service(GrizzlyHttpContainer.java:375)
    at org.glassfish.admin.rest.adapter.RestAdapter$2.service(RestAdapter.java:316)
    at org.glassfish.admin.rest.adapter.RestAdapter.service(RestAdapter.java:179)
    at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
    at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
    at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:283)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:200)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:132)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:111)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:536)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571)
    at java.lang.Thread.run(Thread.java:745)

Answer 1

我现在明白了。

正如 Steve C 所指出的:

包含相关 Bean 的项目与两个 Web 项目一起打包。

简单的解决方案是将依赖项 Maven 范围更改为在 Web 项目中提供，然后将其作为 EAR 中的库提供。

所以回答我的问题:

是的，有一个众所周知的策略来处理此类问题，即确保提供包含共享 Bean 的项目以实现更大的前景，但实际上永远不要将该项目与除目标之外的任何其他项目一起打包耳。

感谢 Steve C 的指导

最诚挚的问候，

J·亚当