private static String readClassName(DataInput di) throws IOException {
    int len = di.readInt();
    byte[] bytes = new byte[len];
    di.readFully(bytes);
    return new String(bytes); // use default decoder
  }
Reads a class name from the given input stream.

@return class name
geode-core/src/main/java/org/apache/geode/internal/cache/persistence/DiskInitFileParser.java