SoftServe

import java.io.*;
import java.util.*;

public abstract class Worker implements Comparable<Worker> {
    private String name;
    private String id;
    private float salary;

    public Worker(String id, String name, float salary) {
        this.id = id;
        this.name = name;
        this.salary = salary;
    }

    public static void writeToFile(String filename, List<Worker> workers)
            throws IOException {
        BufferedWriter bw = new BufferedWriter(new FileWriter(filename));
        for (Worker ww : workers) {
            bw.append(ww.toString());
            bw.newLine();
        }
        bw.close();
    }

    public static String readFromFile(String filename) throws IOException,
            InvalidFileFormatException {
        if (!filename.endsWith("txt"))
            throw new InvalidFileFormatException("Некорректный формат файла");
        BufferedReader br = new BufferedReader(new FileReader(filename));
        String text = "";
        while (br.ready())
            text += br.readLine() + "\r\n";

        br.close();
        return text;
    }

    @Override
    public String toString() {
        return "ID=" + id + ". Name=" + name + " - salary="
                + calculateSalary();
    }

    @Override
    public int compareTo(Worker w) {
        if (this.calculateSalary() > w.calculateSalary())
            return -1;
        if (this.calculateSalary() < w.calculateSalary())
            return 1;

        return this.getName().compareTo(w.getName());
    }

    public abstract float calculateSalary();

    public static void main(String[] args) throws IOException {
        List<Worker> workers = new ArrayList<Worker>();
        workers.add(new HourWorker("01", "Vasya", 5));
        workers.add(new HourWorker("02", "Petya", 4));
        workers.add(new HourWorker("03", "Kolya", 5));
        workers.add(new FixedWorker("04", "Manya", 800));
        workers.add(new FixedWorker("05", "Olya", 800));
        workers.add(new FixedWorker("06", "Lena", 800));
        Collections.sort(workers);

        for (Worker realWorker: workers)
            System.out.println(realWorker);
        System.out.println(" ");

        for (int i = 0; i < 5; i++)
            System.out.println(workers.get(i).getName());
        System.out.println(" ");


for (int i = workers.size() - 3; i < workers.size(); i++)
            System.out.println(workers.get(i).getId());
        writeToFile("C:\\filename.txt", workers);

        try {
            System.out.println(readFromFile("C:\\filename.txt"));
        } catch (Exception e) {
            System.out.println(e.getMessage());

        }

    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public float getSalary() {
        return salary;
    }

    public void setSalary(float salary) {
        this.salary = salary;
    }

}
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public class HourWorker extends Worker {
    public HourWorker(String id, String name, float hourSalary) {
        super(id, name, hourSalary);
    }

    @Override
    public float calculateSalary() {
        return 20.8f * 8 * this.getSalary();
    }
}
__________________________________________________________
public class FixedWorker extends Worker {

    public FixedWorker(String id, String name, float fixedSalary) {
        super(id, name, fixedSalary);
    }

    @Override
    public float calculateSalary() {
        return this.getSalary();
    }
}
__________________________________________________________
import org.omg.PortableInterceptor.INACTIVE;

public class InvalidFileFormatException extends Exception {

    public InvalidFileFormatException(String message) {
        super(message);
    }
}