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POmongodb allanbank async driver callback being called twice
 

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  1. POmongodb allanbank async driver callback being called twice
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    <p>I have a simple callback bound to a <code>findAsync</code> call. Every few requests I observe a failure even though the data in the database is static. </p> <p>Some quick debugging shows that my callback is ALWAYS being called twice. The cases where my app fails are caused by a <code>null</code> <code>MongoIterator&lt;Document&gt;</code> being passed in to my callback. Of course I only expected a single callback when the data is ready (or if there was an exception).</p> <p>Is this expected behavior? Is there something I can do to ensure my callback is only called once when the query is complete?</p> <p>Here is the code snippet:</p> <pre><code>collection.findAsync( [ callback: { MongoIterator&lt;Document&gt; v -&gt; List data = [] try { while(v.hasNext()) { data.add(docToJson(v.next())) } } finally { if (v != null) v.close() } sendReply([ status: 'ok', data: data ]) }, exception: { Throwable t -&gt; sendReply([ status: 'error', message: t.message ]) } ] as Callback&lt;MongoIterator&lt;Document&gt;&gt;, find ) </code></pre> <p>Here is the stack trace:</p> <pre><code>Unexpected MongoDB Connection closed: Auth(MongoDB(43026--&gt;localhost/127.0.0.1:27017)). Will try to reconnect. Reconnected to localhost/127.0.0.1:27017 Exception in thread "MongoDB 43026&lt;--localhost/127.0.0.1:27017" java.lang.NullPointerException: Cannot invoke method hasNext() on null object at org.codehaus.groovy.runtime.NullObject.invokeMethod(NullObject.java:77) at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:45) at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45) at org.codehaus.groovy.runtime.callsite.NullCallSite.call(NullCallSite.java:32) at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45) at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:54) at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:112) at mongoAsync$_run_closure2_closure6.doCall(mongoAsync.groovy:126) at sun.reflect.GeneratedMethodAccessor54.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90) at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:233) at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:272) at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:909) at groovy.lang.Closure.call(Closure.java:411) at org.codehaus.groovy.runtime.ConvertedMap.invokeCustom(ConvertedMap.java:50) at org.codehaus.groovy.runtime.ConversionHandler.invoke(ConversionHandler.java:81) at com.sun.proxy.$Proxy14.callback(Unknown Source) at com.allanbank.mongodb.client.AbstractReplyCallback.handle(AbstractReplyCallback.java:82) at com.allanbank.mongodb.client.AbstractValidatingReplyCallback.callback(AbstractValidatingReplyCallback.java:72) at com.allanbank.mongodb.client.AbstractValidatingReplyCallback.callback(AbstractValidatingReplyCallback.java:33) at com.allanbank.mongodb.connection.message.ReplyHandler.reply(ReplyHandler.java:77) at com.allanbank.mongodb.connection.socket.SocketConnection.reply(SocketConnection.java:560) at com.allanbank.mongodb.connection.socket.SocketConnection$ReceiveRunnable.receiveOne(SocketConnection.java:735) at com.allanbank.mongodb.connection.socket.SocketConnection$ReceiveRunnable.run(SocketConnection.java:683) at java.lang.Thread.run(Thread.java:722) </code></pre>
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    1. CONot expected at all - Can you send me stack traces for the null invocation of the callback (or post here). Email address is Robert.J.Moore at allanbank.com
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      1. USRob Moore
 

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