http - Netty中HttpMessageDecoder.skipControlCharacters上的NullPointerException

在Netty中尝试读取HTTP请求时出现奇怪的错误：

java.lang.NullPointerException
at
 org.jboss.netty.handler.codec.http.HttpMessageDecoder.skipControlCharacters(HttpMessageDecoder.java:409)
at org.jboss.netty.handler.codec.http.HttpMessageDecoder.decode(HttpMessageDecoder.java:184)
at org.jboss.netty.handler.codec.http.HttpMessageDecoder.decode(HttpMessageDecoder.java:107)
at org.jboss.netty.handler.codec.replay.ReplayingDecoder.callDecode(ReplayingDecoder.java:470)
at org.jboss.netty.handler.codec.replay.ReplayingDecoder.messageReceived(ReplayingDecoder.java:443)
at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:274)
at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:261)
at org.jboss.netty.channel.socket.nio.NioWorker.read(NioWorker.java:351)
at org.jboss.netty.channel.socket.nio.NioWorker.processSelectedKeys(NioWorker.java:282)
at org.jboss.netty.channel.socket.nio.NioWorker.run(NioWorker.java:202)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:679)

堆栈跟踪不会出现在我的代码中，我不知道如何调试它？

class RouteHandler(default: Tuple2[String, Int]) extends SimpleChannelUpstreamHandler {

  override def handleUpstream(ctx: ChannelHandlerContext, e: ChannelEvent) {
    e match {
      case evt: UpstreamMessageEvent =>
        evt.getMessage match {
          case req: HttpRequest => {
            val projectHdr = req.getHeader("HDR")
            RouteHandler.log.info("Project ID: {}", projectHdr)
            val backendServerUri = projectHdr match {
              case null => default
              case uri: String =>
                if (ObjectId.isValid(projectHdr)) {
                  val serverData = MappingService.resolveServer(new ObjectId(projectHdr))
                  (serverData.host(), serverData.port())
                }
                else
                  default
            }
            RouteHandler.log.info("Route to {}", backendServerUri)
            val pipeline = ctx.getPipeline
            pipeline.synchronized {
              val handler = new ForwardRequestHandler(backendServerUri._1, backendServerUri._2)
              pipeline.get(HANDLER_NAME) match {
                case null => pipeline.addLast(HANDLER_NAME, handler)
                case _ => pipeline.replace(HANDLER_NAME, HANDLER_NAME, handler)
              }
            }
          }
          case z => RouteHandler.log.warn("Can not handle {}", z.getClass)
        }
      case z: DefaultExceptionEvent => RouteHandler.log.error("Exception from Netty", z.getCause)
      case z =>
    }
    super.handleUpstream(ctx, e)
  }

  override def exceptionCaught(ctx: ChannelHandlerContext, e: ExceptionEvent) {
    RouteHandler.log.error("Caught", e.getCause)
    e.getChannel.close()
  }
}

最佳答案

所以就为了记录…错误是httpMessageDecoder是跨通道共享的，这是不允许的，因为它没有用t@sharable注释

关于http - Netty中HttpMessageDecoder.skipControlCharacters上的NullPointerException，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/11832764/