parquet-common/src/main/java/org/apache/parquet/bytes/LittleEndianDataInputStream.java
public final long readLong() throws IOException {
    // TODO: see perf question above in readInt
    readFully(readBuffer, 0, 8);
    return (((long)readBuffer[7] << 56) +
        ((long)(readBuffer[6] & 255) << 48) +
        ((long)(readBuffer[5] & 255) << 40) +
        ((long)(readBuffer[4] & 255) << 32) +
        ((long)(readBuffer[3] & 255) << 24) +
        ((readBuffer[2] & 255) << 16) +
        ((readBuffer[1] & 255) <<  8) +
        ((readBuffer[0] & 255) <<  0));
  }
public final long readLong() throws IOException {
    // TODO: see perf question above in readInt
    readFully(readBuffer, 0, 8);
    return (((long)readBuffer[7] << 56) +
        ((long)(readBuffer[6] & 255) << 48) +
        ((long)(readBuffer[5] & 255) << 40) +
        ((long)(readBuffer[4] & 255) << 32) +
        ((long)(readBuffer[3] & 255) << 24) +
        ((readBuffer[2] & 255) << 16) +
        ((readBuffer[1] & 255) <<  8) +
        ((readBuffer[0] & 255) <<  0));
  }
public final long readLong ( ) throws IOException { // TODO: see perf question above in readInt readFully ( readBuffer , 0 , 8 ) ; return ( ( ( long ) readBuffer [ 7 ] << 56 ) + ( ( long ) ( readBuffer [ 6 ] & 255 ) << 48 ) + ( ( long ) ( readBuffer [ 5 ] & 255 ) << 40 ) + ( ( long ) ( readBuffer [ 4 ] & 255 ) << 32 ) + ( ( long ) ( readBuffer [ 3 ] & 255 ) << 24 ) + ( ( readBuffer [ 2 ] & 255 ) << 16 ) + ( ( readBuffer [ 1 ] & 255 ) << 8 ) + ( ( readBuffer [ 0 ] & 255 ) << 0 ) ) ; }
Bytes
for this operation are read from the contained
input stream.

@return     the next eight bytes of this input stream, interpreted as a
<code>long</code>.
@exception  EOFException  if this input stream reaches the end before
reading eight bytes.
@exception  IOException   the stream has been closed and the contained
input stream does not support reading after close, or
another I/O error occurs.
@see        java.io.FilterInputStream#in
Bytes for this operation are read from the contained input stream .