private int rawReadInt(InputStream in) throws IOException {
      int b1 = in.read();
      int b2 = in.read();
      int b3 = in.read();
      int b4 = in.read();
      if ((b1 | b2 | b3 | b4) < 0) throw new EOFException();
      return ((b1 << 24) + (b2 << 16) + (b3 << 8) + (b4 << 0));
    }
Read an integer from the stream in big-endian byte order.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/wal/CompressionContext.java