[GitHub] [arrow] davisusanibar commented on issue #34850: [Java] pandas created arrow files cause exception in Java using ArrowFileReader API

["davisusanibar (via GitHub)" <gi...@apache.org>]

davisusanibar commented on issue #34850:
URL: https://github.com/apache/arrow/issues/34850#issuecomment-1496273772

   > I figured out what was causing it. Appears that adding explicit `compression='uncompressed'` on python export side will result in correct processing. Does `ArrowFileReader` support compression which is turned on by default on Python side?
   
   Hi @tklinchik , use CommonsCompressionFactory for compressed files (Lz4/Zstd currently supported)
   
   ```
   File file = new File("lz4.arrow");
   try (
       BufferAllocator rootAllocator = new RootAllocator();
       FileInputStream fileInputStream = new FileInputStream(file);
       // ArrowFileReader reader = new ArrowFileReader(fileInputStream.getChannel(), rootAllocator) // Use CommonsCompressionFactory for compressed files
       ArrowFileReader reader = new ArrowFileReader(fileInputStream.getChannel(),
           rootAllocator, CommonsCompressionFactory.INSTANCE)
   ) {
       System.out.println("Record batches in file: " + reader.getRecordBlocks().size());
       for (ArrowBlock arrowBlock : reader.getRecordBlocks()) {
           reader.loadRecordBatch(arrowBlock);
           VectorSchemaRoot vectorSchemaRootRecover = reader.getVectorSchemaRoot();
           System.out.println("Size: --> " + vectorSchemaRootRecover.getRowCount());
           System.out.print(vectorSchemaRootRecover.contentToTSVString());
       }
   } catch (IOException e) {
       e.printStackTrace();
   } 
   ```


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