dependency inversion principle

import java.io.FileWriter;
import java.io.IOException;

interface ILoger {
    void log(final String message);
}

class FileLogger implements ILoger {
    private FileWriter fileWriter;
    public FileLogger(final String fName) throws IOException {
        fileWriter = new FileWriter(fName);
    }

    @Override
    public void log(final String message) {
        try {
            fileWriter.write(System.currentTimeMillis() + ": " + message);
            fileWriter.close();
        } catch (Exception e) {
            System.err.println("ERROR: ");
            e.printStackTrace();
        }
    }
}

class DataAccessLayer {
    private ILoger loger;
    public DataAccessLayer(final ILoger loger) {
        this.loger = loger;
    }
    public void addClient(final String name) {
        loger.log("added " + name);
    }
}

public class Main {

    public static void main(String[] args) throws IOException {
        var fl = new FileLogger("data.txt");
        var dal = new DataAccessLayer(fl);
        dal.addClient("Andrew");
    }
}