关于flex同java通信出现的问题

前台flex与后台java通信使用的是BlazeDS，之前的同事配置完了，一直在用，没有出现任何问题，偶然又一次发现前台页面报错：

(mx.messaging.messages::ErrorMessage)#0

  body = (Object)#1
  clientId = (null)
  correlationId = "F8277DBC-2D0B-2A34-316F-CC87A3470557"
  destination = ""
  extendedData = (null)
  faultCode = "Client.Error.MessageSend"
  faultDetail = "Channel.Ping.Failed error Detected duplicate HTTP-based FlexSessions, generally due to the remote host disabling session cookies. Session cookies must be enabled to manage the client connection correctly. url: 'http://42.96.163.0:9018/LB_GIS_Server/messagebroker/amf'"
  faultString = "Send failed"
  headers = (Object)#2
  messageId = "450D23A1-0C12-DEF1-BBBE-CC87A39A2467"
  rootCause = (mx.messaging.events::ChannelFaultEvent)#3
    bubbles = false
    cancelable = false
    channel = (mx.messaging.channels::AMFChannel)#4
      authenticated = false
      channelSets = (Array)#5
      connected = false
      connectTimeout = -1
      enableSmallMessages = true
      endpoint = "http://42.96.163.0:9018/LB_GIS_Server/messagebroker/amf"
      failoverURIs = (Array)#6
      id = (null)
      mpiEnabled = false
      netConnection = (flash.net::NetConnection)#7
        client = (mx.messaging.channels::AMFChannel)#4
        connected = false
        maxPeerConnections = 8
        objectEncoding = 3
        proxyType = "none"
        uri = "http://42.96.163.0:9018/LB_GIS_Server/messagebroker/amf"
      piggybackingEnabled = false
      polling = false
      pollingEnabled = true
      pollingInterval = 3000
      protocol = "http"
      reconnecting = false
      recordMessageSizes = false
      recordMessageTimes = false
      requestTimeout = -1
      uri = "http://42.96.163.0:9018/LB_GIS_Server/messagebroker/amf"
      url = "http://42.96.163.0:9018/LB_GIS_Server/messagebroker/amf"
      useSmallMessages = false
    channelId = (null)
    connected = false
    currentTarget = (mx.messaging.channels::AMFChannel)#4
    eventPhase = 2
    faultCode = "Channel.Ping.Failed"
    faultDetail = "Detected duplicate HTTP-based FlexSessions, generally due to the remote host disabling session cookies. Session cookies must be enabled to manage the client connection correctly. url: 'http://42.96.163.0:9018/LB_GIS_Server/messagebroker/amf'"
    faultString = "error"
    reconnecting = false
    rejected = false
    rootCause = (mx.messaging.messages::ErrorMessage)#8
      body = (null)
      clientId = (null)
      correlationId = "2E53D1F1-0737-4736-E990-CC87A364EF53"
      destination = ""
      extendedData = (null)
      faultCode = "Server.Processing.DuplicateSessionDetected"
      faultDetail = (null)
      faultString = "Detected duplicate HTTP-based FlexSessions, generally due to the remote host disabling session cookies. Session cookies must be enabled to manage the client connection correctly."
      headers = (Object)#9
      messageId = "B44C8045-E90E-BF16-862D-70C66C8E349B"
      rootCause = (null)
      timestamp = 1450835134201
      timeToLive = 0
    target = (mx.messaging.channels::AMFChannel)#4
    type = "channelFault"
  timestamp = 0

  timeToLive = 0

想了一下最近也没有改过任何配置，是不可能是配置的问题，最终发现在remote-config.xml中有两个服务id对应了同一个class才导致了上面的错误，修改后前台正常访问