parquet-hadoop/src/main/java/org/apache/parquet/hadoop/ParquetFileWriter.java
public void startColumn(ColumnDescriptor descriptor,
                          long valueCount,
                          CompressionCodecName compressionCodecName) throws IOException {
    state = state.startColumn();
    encodingStatsBuilder.clear();
    currentEncodings = new HashSet<Encoding>();
    currentChunkPath = ColumnPath.get(descriptor.getPath());
    currentChunkType = descriptor.getPrimitiveType();
    currentChunkCodec = compressionCodecName;
    currentChunkValueCount = valueCount;
    currentChunkFirstDataPage = out.getPos();
    compressedLength = 0;
    uncompressedLength = 0;
    // The statistics will be copied from the first one added at writeDataPage(s) so we have the correct typed one
    currentStatistics = null;

    columnIndexBuilder = ColumnIndexBuilder.getBuilder(currentChunkType, columnIndexTruncateLength);
    offsetIndexBuilder = OffsetIndexBuilder.getBuilder();
    firstPageOffset = -1;
  }
public void startColumn(ColumnDescriptor descriptor,
                          long valueCount,
                          CompressionCodecName compressionCodecName) throws IOException {
    state = state.startColumn();
    encodingStatsBuilder.clear();
    currentEncodings = new HashSet<Encoding>();
    currentChunkPath = ColumnPath.get(descriptor.getPath());
    currentChunkType = descriptor.getPrimitiveType();
    currentChunkCodec = compressionCodecName;
    currentChunkValueCount = valueCount;
    currentChunkFirstDataPage = out.getPos();
    compressedLength = 0;
    uncompressedLength = 0;
    // The statistics will be copied from the first one added at writeDataPage(s) so we have the correct typed one
    currentStatistics = null;

    columnIndexBuilder = ColumnIndexBuilder.getBuilder(currentChunkType, columnIndexTruncateLength);
    offsetIndexBuilder = OffsetIndexBuilder.getBuilder();
    firstPageOffset = -1;
  }
start a column inside a block
@param descriptor the column descriptor
@param valueCount the value count in this column
@param compressionCodecName a compression codec name
@throws IOException if there is an error while writing