davisusanibar commented on issue #37323:
URL: https://github.com/apache/arrow/issues/37323#issuecomment-1690360880
Hi @zinking ,
You could try with this:
1. Go to arrow/java/dataset
2. Get your absolute path of your new dataset native library: i.e
$PWD/lib/x86_64/libarrow_dataset_jni.so
3. Build new Java Dataset module:
`mvn clean install -Darrow.cpp.build.dir=$PWD/lib`
5. Test your new dataset library with:
```java
import org.apache.arrow.dataset.file.FileFormat;
import org.apache.arrow.dataset.file.FileSystemDatasetFactory;
import org.apache.arrow.dataset.jni.NativeMemoryPool;
import org.apache.arrow.dataset.scanner.ScanOptions;
import org.apache.arrow.dataset.scanner.Scanner;
import org.apache.arrow.dataset.source.Dataset;
import org.apache.arrow.dataset.source.DatasetFactory;
import org.apache.arrow.memory.BufferAllocator;
import org.apache.arrow.memory.RootAllocator;
import org.apache.arrow.vector.ipc.ArrowReader;
import org.apache.arrow.vector.types.pojo.Schema;
public class ReadHdfsParquet {
public static void main(String[] args) {
//declare JVM environment variable: HADOOP_HOME =
/Users/dsusanibar/hadoop-3.3.2
//where to search for: lib/native/libhdfs.dylib
String uri =
"hdfs://localhost:9000/Users/dsusanibar/data4_2rg_gzip.parquet";
ScanOptions options = new ScanOptions(/*batchSize*/ 32768);
try (
BufferAllocator allocator = new RootAllocator();
DatasetFactory datasetFactory = new
FileSystemDatasetFactory(allocator, NativeMemoryPool.getDefault(),
FileFormat.PARQUET, uri);
Dataset dataset = datasetFactory.finish();
Scanner scanner = dataset.newScan(options);
ArrowReader reader = scanner.scanBatches()
) {
Schema schema = scanner.schema();
System.out.println(schema);
while (reader.loadNextBatch()) {
System.out.println(reader.getVectorSchemaRoot().contentToTSVString());
System.out.println("RowCount: " +
reader.getVectorSchemaRoot().getRowCount());
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
```
I was able to read HDFS parquet files, but the program will not shut down
for some reason.
**Please let me know if you obtain the same result on your side.**
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