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javaniobytebufferfilechannel

How to avoid OutOfMemoryError when using Bytebuffers and NIO?

I'm using ByteBuffers and FileChannels to write binary data to a file. When doing that for big files or successively for multiple files, I get an OutOfMemoryError exception. I've read elsewhere that using Bytebuffers with NIO is broken and should be avoided. Does any of you already faced this kind of problem and found a solution to efficiently save large amounts of binary data in a file in java?

Is the jvm option -XX:MaxDirectMemorySize the way to go?

Solution

  • I would say don't create a huge ByteBuffer that contains ALL of the data at once. Create a much smaller ByteBuffer, fill it with data, then write this data to the FileChannel. Then reset the ByteBuffer and continue until all the data is written.