java - Play Framework 注入(inject)错误

Question

我正在尝试使用 Play 2.5 将 JPAApi 注入(inject)我的 Controller ，但我不断收到以下异常。

com.google.inject.ProvisionException:无法提供，请参阅以下错误:

1) Error injecting constructor, java.lang.NoClassDefFoundError: org/dom4j/io/STAXEventReader
  at play.db.jpa.DefaultJPAApi$JPAApiProvider.<init>(DefaultJPAApi.java:39)
  at play.db.jpa.DefaultJPAApi$JPAApiProvider.class(DefaultJPAApi.java:34)
  while locating play.db.jpa.DefaultJPAApi$JPAApiProvider
  while locating play.db.jpa.JPAApi
    for parameter 0 at controllers.HomeController.<init>(HomeController.java:20)
  while locating controllers.HomeController
    for parameter 1 at router.Routes.<init>(Routes.scala:40)
  while locating router.Routes
  while locating play.api.inject.RoutesProvider
  while locating play.api.routing.Router
    for parameter 0 at play.api.http.JavaCompatibleHttpRequestHandler.<init>(HttpRequestHandler.scala:200)
  while locating play.api.http.JavaCompatibleHttpRequestHandler
  while locating play.api.http.HttpRequestHandler
    for parameter 4 at play.api.DefaultApplication.<init>(Application.scala:221)
  at play.api.DefaultApplication.class(Application.scala:221)
  while locating play.api.DefaultApplication
  while locating play.api.Application

1 error
     com.google.inject.internal.InjectorImpl$2.get(InjectorImpl.java:1025)
     com.google.inject.internal.InjectorImpl.getInstance(InjectorImpl.java:1051)
     play.api.inject.guice.GuiceInjector.instanceOf(GuiceInjectorBuilder.scala:405)
     play.api.inject.guice.GuiceInjector.instanceOf(GuiceInjectorBuilder.scala:400)
     play.api.inject.guice.GuiceApplicationBuilder.build(GuiceApplicationBuilder.scala:123)
     play.api.inject.guice.GuiceApplicationLoader.load(GuiceApplicationLoader.scala:21)
     play.core.server.DevServerStart$$anonfun$mainDev$1$$anon$1$$anonfun$get$1$$anonfun$apply$1$$anonfun$1$$anonfun$2.apply(DevServerStart.scala:158)
     play.core.server.DevServerStart$$anonfun$mainDev$1$$anon$1$$anonfun$get$1$$anonfun$apply$1$$anonfun$1$$anonfun$2.apply(DevServerStart.scala:155)
     play.utils.Threads$.withContextClassLoader(Threads.scala:21)
     play.core.server.DevServerStart$$anonfun$mainDev$1$$anon$1$$anonfun$get$1$$anonfun$apply$1$$anonfun$1.apply(DevServerStart.scala:155)
     play.core.server.DevServerStart$$anonfun$mainDev$1$$anon$1$$anonfun$get$1$$anonfun$apply$1$$anonfun$1.apply(DevServerStart.scala:126)
     scala.Option.map(Option.scala:146)
     play.core.server.DevServerStart$$anonfun$mainDev$1$$anon$1$$anonfun$get$1$$anonfun$apply$1.apply(DevServerStart.scala:126)
     play.core.server.DevServerStart$$anonfun$mainDev$1$$anon$1$$anonfun$get$1$$anonfun$apply$1.apply(DevServerStart.scala:124)
     scala.util.Success.flatMap(Try.scala:231)
     play.core.server.DevServerStart$$anonfun$mainDev$1$$anon$1$$anonfun$get$1.apply(DevServerStart.scala:124)
     play.core.server.DevServerStart$$anonfun$mainDev$1$$anon$1$$anonfun$get$1.apply(DevServerStart.scala:116)
     scala.concurrent.impl.Future$PromiseCompletingRunnable.liftedTree1$1(Future.scala:24)
     scala.concurrent.impl.Future$PromiseCompletingRunnable.run(Future.scala:24)
     java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(ForkJoinTask.java:1402)
     java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
     java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
     java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692)
     java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)

这是我的 Controller 。

public class HomeController extends Controller {

    private JPAApi jpaApi;

    @Inject
    public HomeController(JPAApi jpaApi) {
        this.jpaApi = jpaApi;
    }

    public Result index() {
        jpaApi.withTransaction(entityManager -> {
            Query query = entityManager.createNativeQuery("select max(age) from people");
            return (Long) query.getSingleResult();
        });
        return ok(index.render("Your new application is ready."));
    }

}

Answer 1

您刚刚在 sbt(Play 正在使用的构建工具)中遇到了一个错误。 这个错误出现在 Hibernate 版本 5.2.1(但不是 5.2.0)。

Hibernate 5.2.1 开始使用 sbt 无法处理的 maven 语法排除所有 dom4j 的传递依赖。

目前的解决方法是添加

"dom4j" % "dom4j" % "1.6.1" intransitive()

到 build.sbt 中的 libraryDependencies(与 Hibernate 依赖项并行)。

有关更多详细信息，请查看 sbt 错误本身，可在此处找到:https://github.com/sbt/sbt/issues/1431

我报告的 Hibernate 错误(但已被关闭，因为它原来是一个 sbt 问题)可以在这里找到: https://hibernate.atlassian.net/browse/HHH-10916