将Lucene集成到play框架中

Yang 发表于 Dev

那

我正在尝试将Lucene集成到Web应用程序中。（不用于全文索引，而是用于快速搜索和排序。）我创建了一个服务：

trait Index {
  def indexAd(a: Ad): Unit
}

@Singleton
class ConcreteIndex @Inject()(conf: Configuration) extends Index {
  val dir =     FSDirectory.open(FileSystems.getDefault.getPath(conf.getString("index.dir").get))
  val writer = new IndexWriter(dir, new IndexWriterConfig(new StandardAnalyzer))
    override def indexAd(a: Ad): Unit = {
        val doc = new Document
        ...
    }
}

并尝试在控制器中使用它：

@Singleton
class AdsController @Inject()(cache: CacheApi, index:Index) extends Controller {
  ...
}

但是注射不成功。我有

Error injecting constructor, org.apache.lucene.store.LockObtainFailedException: 
 Lock held by this virtual machine: .../backend/index/write.lock

我试图删除锁定文件，然后重新运行。它仍然引发相同的异常。有人可以帮我吗？我正在使用Lucene 6.2.0。播放2.5.x，scala 2.11.8

迈克斯名

您可能需要确保IndexWriter在关机时将其关闭以清除锁定。这可能是一项昂贵的操作，因此您可能希望将索引编写器的生命周期与Play应用程序的生命周期联系在一起，在（单例）ConcreteIndex实例的构造函数中启动它，然后通过向注入的ApplicationLifecycle实例添加停止挂钩来关闭它。例如：

@ImplementedBy(classOf[ConcreteIndex])
trait Index {
  def index(s: String): Unit
}

@Singleton
case class ConcreteIndex @Inject()(conf: Configuration,
                                   lifecycle: play.api.inject.ApplicationLifecycle) extends Index {

  private val dir = FSDirectory.open(FileSystems.getDefault.getPath(conf.getString("index.dir").get))
  private val writer = new IndexWriter(dir, new IndexWriterConfig(new StandardAnalyzer()))

  // Add a lifecycle stop hook that will be called when the Play
  // server is cleanly shut down...
  lifecycle.addStopHook(() => scala.concurrent.Future.successful(writer.close()))

  // For good measure you could also add a JVM runtime shutdown hook
  // which should be called even if the Play server is terminated.
  // If the writer is already closed this will be a no-op.
  Runtime.getRuntime.addShutdownHook(new Thread() { 
    override def run() = writer.close()
  })

  def index(s: String): Unit = ???
}

本文收集自互联网，转载请注明来源。

如有侵权，请联系 [email protected] 删除。