修订版1（@nico_ekito）：

Question

我在OSGi环境下使用ActiveMQ 5.3.0两年没有任何明显的问题。

现在，我需要为发布/订阅特定主题的用户添加授权管理。为此，我开发了一个插件，在方法

中实现了org.apache.activemq.security.MessageAuthorizationPolicy：

public boolean isAllowedToConsume(ConnectionContext context, Message message)

我在那里读取传入的消息，我检查当前用户是否允许使用这样的消息，并且我相应地返回true / false进行此检查。特别是，我使用短信（简短的XML片段......），所以，我使用这个片段来读取当前的TextMessage：

if (message instanceof TextMessage) {
   String xmlText = "";
   try {
       xmlText = xml.getText();
       System.out.println(xmlText);
       ... //parse the message and check for permission...
    } catch (JMSException e) {
        ... //manage exception
    }
}

在我看来（但也许我错了!!）此代码使用org.apache.activemq.openwire.v5.MessageMarshaller中包含的代码创建了一场竞赛：

public void tightMarshal2(OpenWireFormat wireFormat, Object o, DataOutput dataOut, BooleanStream bs) throws IOException {
   ...
   tightMarshalByteSequence2(info.getContent(), dataOut, bs); //here, info.getContent() is null!!
   ...
}

实际上我收到了一个NullPointerException，其stacktrace是：

 Exception in thread "BrokerService" 
 java.lang.NullPointerException
at org.apache.activemq.openwire.v5.BaseDataStreamMarshaller.tightMarshalByteSequence2(BaseDataStreamMarshaller.java:431)
at org.apache.activemq.openwire.v5.MessageMarshaller.tightMarshal2(MessageMarshaller.java:180)
at org.apache.activemq.openwire.v5.ActiveMQMessageMarshaller.tightMarshal2(ActiveMQMessageMarshaller.java:89)
at org.apache.activemq.openwire.v5.ActiveMQTextMessageMarshaller.tightMarshal2(ActiveMQTextMessageMarshaller.java:89)
at org.apache.activemq.openwire.OpenWireFormat.tightMarshalNestedObject2(OpenWireFormat.java:430)
at org.apache.activemq.openwire.v5.BaseDataStreamMarshaller.tightMarshalNestedObject2(BaseDataStreamMarshaller.java:136)
at org.apache.activemq.openwire.v5.MessageDispatchMarshaller.tightMarshal2(MessageDispatchMarshaller.java:105)
at org.apache.activemq.openwire.OpenWireFormat.marshal(OpenWireFormat.java:240)
at org.apache.activemq.transport.tcp.TcpTransport.oneway(TcpTransport.java:166)
at org.apache.activemq.transport.InactivityMonitor.oneway(InactivityMonitor.java:237)
at org.apache.activemq.transport.TransportFilter.oneway(TransportFilter.java:83)
at org.apache.activemq.transport.WireFormatNegotiator.oneway(WireFormatNegotiator.java:104)
at org.apache.activemq.transport.MutexTransport.oneway(MutexTransport.java:40)
at org.apache.activemq.broker.TransportConnection.dispatch(TransportConnection.java:1190)
at org.apache.activemq.broker.TransportConnection.processDispatch(TransportConnection.java:779)
at org.apache.activemq.broker.TransportConnection.iterate(TransportConnection.java:815)
at org.apache.activemq.thread.PooledTaskRunner.runTask(PooledTaskRunner.java:122)
at org.apache.activemq.thread.PooledTaskRunner$1.run(PooledTaskRunner.java:43)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

现在，如果我删除片段以在isAllowedToConsume（...）中读取消息的XML内容，那么所有的seeems都会正常返回，但我需要这样的控件!!!

那么，有没有办法正确读取TextMessage而不影响其他消费者呢？

非常感谢，对不起这个长期的问题感到抱歉!!

再见 cghersi

修订版1（@nico_ekito）：

这里有完整的isAllowedToConsume（）方法：

public boolean isAllowedToConsume(ConnectionContext context, Message message) { 
  String msgFrom = message.getDestination().getPhysicalName();              
  String textOfMsg = "";
  if(message instanceof TextMessage){
    TextMessage xml = (TextMessage)message;
    try {
      textOfMsg = xml.getText();
    } catch (JMSException e) {
      return false;
    }
  } else    
    return false;   

  //do my checks on textOfMsg returning true/false...       
}

ActiveMQ：检查授权时代理上的NullPointerException

修订版1（@nico_ekito）：

0 个答案: