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Type:
Task
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Resolution: Done
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Priority:
Major - P3
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None
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Affects Version/s: 3.8.1
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Component/s: Async, Query Operations
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Labels:None
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Environment:Ubuntu Linux operating system.
I am retrieving the documents from the MongoDB with the collection.find().into() to generate the documents. The following is the code -
List<Document> scrapingInformation = new LinkedList<>(); database.getCollection(scrapingInformationByClientidJobid) .find(and(eq("clientId", clientId), eq("jobId", jobId))) .into(scrapingInformation, (res, ex) -> { ex.printStackTrace(); System.out.println("Exception while iterating over the finditerable and adding to document list: " + ex.getMessage()); } ); System.out.println("Total populated documents in list: " + scrapingInformation.size());{{ }}
Data is there in the database. The find() method reads that data as well. The problem comes when I try to iterate on the data. I tried iterating over the FindIterable as well. There was also the NullPointerException.
The version I installed is 4.0 and driver 3.8.1. To remove the possibility of version conflict I downgraded to 3.6.1 and still, there is the problem.
Following is the stacktrace:
java.lang.NullPointerException at com.fastscraping.dao.mongo.ScrapingInformationDB.lambda$getScrapingInformation$2(ScrapingInformationDB.java:71) at com.mongodb.async.client.MongoIterableImpl$2$2.onResult(MongoIterableImpl.java:110) at com.mongodb.async.client.MongoIterableImpl$2$2.onResult(MongoIterableImpl.java:104) at com.mongodb.async.client.MongoIterableImpl$4.onResult(MongoIterableImpl.java:171) at com.mongodb.async.client.MongoIterableImpl$4.onResult(MongoIterableImpl.java:166) at com.mongodb.operation.AsyncQueryBatchCursor.next(AsyncQueryBatchCursor.java:141) at com.mongodb.operation.AsyncQueryBatchCursor.next(AsyncQueryBatchCursor.java:100) at com.mongodb.async.client.MongoIterableImpl.loopCursor(MongoIterableImpl.java:166) at com.mongodb.async.client.MongoIterableImpl.access$000(MongoIterableImpl.java:34) at com.mongodb.async.client.MongoIterableImpl$4.onResult(MongoIterableImpl.java:177) at com.mongodb.async.client.MongoIterableImpl$4.onResult(MongoIterableImpl.java:166) at com.mongodb.operation.AsyncQueryBatchCursor.next(AsyncQueryBatchCursor.java:136) at com.mongodb.operation.AsyncQueryBatchCursor.next(AsyncQueryBatchCursor.java:100) at com.mongodb.async.client.MongoIterableImpl.loopCursor(MongoIterableImpl.java:166) at com.mongodb.async.client.MongoIterableImpl.access$000(MongoIterableImpl.java:34) at com.mongodb.async.client.MongoIterableImpl$2.onResult(MongoIterableImpl.java:99) at com.mongodb.async.client.MongoIterableImpl$2.onResult(MongoIterableImpl.java:93) at com.mongodb.internal.async.ErrorHandlingResultCallback.onResult(ErrorHandlingResultCallback.java:49) at com.mongodb.async.client.OperationExecutorImpl$1$1.onResult(OperationExecutorImpl.java:82) at com.mongodb.internal.async.ErrorHandlingResultCallback.onResult(ErrorHandlingResultCallback.java:49) at com.mongodb.operation.FindOperation$3.onResult(FindOperation.java:806) at com.mongodb.operation.OperationHelper$ReferenceCountedReleasingWrappedCallback.onResult(OperationHelper.java:364) at com.mongodb.operation.CommandOperationHelper$2.onResult(CommandOperationHelper.java:405) at com.mongodb.internal.async.ErrorHandlingResultCallback.onResult(ErrorHandlingResultCallback.java:49) at com.mongodb.internal.connection.DefaultServer$DefaultServerProtocolExecutor$2.onResult(DefaultServer.java:227) at com.mongodb.internal.async.ErrorHandlingResultCallback.onResult(ErrorHandlingResultCallback.java:49) at com.mongodb.internal.connection.CommandProtocolImpl$1.onResult(CommandProtocolImpl.java:85) at com.mongodb.internal.connection.DefaultConnectionPool$PooledConnection$1.onResult(DefaultConnectionPool.java:461) at com.mongodb.internal.connection.UsageTrackingInternalConnection$2.onResult(UsageTrackingInternalConnection.java:111) at com.mongodb.internal.async.ErrorHandlingResultCallback.onResult(ErrorHandlingResultCallback.java:49) at com.mongodb.internal.connection.InternalStreamConnection$2$1.onResult(InternalStreamConnection.java:379) at com.mongodb.internal.connection.InternalStreamConnection$2$1.onResult(InternalStreamConnection.java:356) at com.mongodb.internal.connection.InternalStreamConnection$MessageHeaderCallback$MessageCallback.onResult(InternalStreamConnection.java:651) at com.mongodb.internal.connection.InternalStreamConnection$MessageHeaderCallback$MessageCallback.onResult(InternalStreamConnection.java:618) at com.mongodb.internal.connection.InternalStreamConnection$5.completed(InternalStreamConnection.java:494) at com.mongodb.internal.connection.InternalStreamConnection$5.completed(InternalStreamConnection.java:491) at com.mongodb.connection.netty.NettyStream.readAsync(NettyStream.java:236) at com.mongodb.internal.connection.InternalStreamConnection.readAsync(InternalStreamConnection.java:491) at com.mongodb.internal.connection.InternalStreamConnection.access$1000(InternalStreamConnection.java:74) at com.mongodb.internal.connection.InternalStreamConnection$MessageHeaderCallback.onResult(InternalStreamConnection.java:608) at com.mongodb.internal.connection.InternalStreamConnection$MessageHeaderCallback.onResult(InternalStreamConnection.java:593) at com.mongodb.internal.connection.InternalStreamConnection$5.completed(InternalStreamConnection.java:494) at com.mongodb.internal.connection.InternalStreamConnection$5.completed(InternalStreamConnection.java:491) at com.mongodb.connection.netty.NettyStream.readAsync(NettyStream.java:236) at com.mongodb.connection.netty.NettyStream.handleReadResponse(NettyStream.java:266) at com.mongodb.connection.netty.NettyStream.access$600(NettyStream.java:66) at com.mongodb.connection.netty.NettyStream$InboundBufferHandler.channelRead0(NettyStream.java:325) at com.mongodb.connection.netty.NettyStream$InboundBufferHandler.channelRead0(NettyStream.java:322) at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:349) at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:341) at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1334) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:349) at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:926) at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:129) at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:642) at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:565) at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:479) at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:441) at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858) at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:144) at java.lang.Thread.run(Thread.java:748)
What could be the cause of this exception?