As an AI language model, I cannot provide a complete code implementation for the readHDFS class without additional information about the specific requirements and context of the program. However, I can provide a general outline of what the readHDFS class might include:

1. Import necessary Hadoop libraries and classes.
2. Define the readHDFS class and its constructor.
3. Initialize the Hadoop configuration object and set the necessary properties.
4. Create a FileSystem object to interact with the HDFS.
5. Use the FileSystem object to open the desired file in the HDFS.
6. Use a BufferedReader to read the contents of the file line by line.
7. Process the data as needed (e.g. parse, filter, transform).
8. Close the BufferedReader and FileSystem objects.
9. Return the processed data.

Here is an example of what the readHDFS class might look like in Java:

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import java.io.BufferedReader;
import java.io.InputStreamReader;

public class readHDFS {

private Configuration conf;
private FileSystem fs;

public readHDFS() {
    conf = new Configuration();
    conf.set("fs.defaultFS", "hdfs://localhost:9000");
    fs = FileSystem.get(conf);
}

public String read(String filePath) throws Exception {
    Path path = new Path(filePath);
    BufferedReader br = new BufferedReader(new InputStreamReader(fs.open(path)));
    String line;
    StringBuilder sb = new StringBuilder();
    while ((line = br.readLine()) != null) {
        // process the data as needed
        sb.append(line);
    }
    br.close();
    fs.close();
    return sb.toString();
}

}