Untitled

public
    class MainEgzamin {
/*
Zawartość metody main jest tylko kodem testowym, zgodnie z
treścią zadania nie należało go tworzyć
 */
    public static void main(String[] args) {

        // Prog. testowy zestaw A
        {
            Student[] students = {
                new Student("Stanislaw", "Moczulski", 23),
                new Student("Zuzanna", "Kasztany", 1944)
            };

            try {
                FileOutputStream fos = new FileOutputStream(".//wyniki.txt");
                Student.putStudentsToFileZestawA(fos, students);
                fos.close();
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        // Prog. testowy zestaw B
        {
            Student[] students = null;
            try {
                FileInputStream fis = new FileInputStream(".//wyniki.txt");
                students = Student.getStudentsFromFileZestawB(fis);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        // Prog. testowy - poza zestawami
        {
            Student[] students = {
                    new Student("Stanislaw", "Moczulski", 23),
                    new Student("Zuzanna", "Kasztany", 1944)
            };
            try {
                FileOutputStream fos = new FileOutputStream(".//wyniki.bin");
                Student.putStudentsToBinFile(fos, students);
                fos.close();
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        // Prog. testowy zestaw C
        {
            Student[] students = null;
            try {
                FileInputStream fis = new FileInputStream(".//wyniki.bin");
                students = Student.getStudentsFromFileZestawC(fis);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        // Prog. testowy zestaw D
        {
            Student[] students = null;
            try {
                FileInputStream fis = new FileInputStream(".//wyniki.bin");
                students = Student.getStudentsFromFileZestawD(fis);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

class Osoba{
    private String fName;
    private String sName;

    protected Osoba(String fName, String sName){
        this.fName = fName;
        this.sName = sName;
    }
    protected String getFName(){
        return fName;
    }
    protected String getSName(){
        return sName;
    }
    public String toString(){
        return super.toString()+" "+fName+" "+sName;
    }
}

class Student
    extends Osoba {

    protected int indexNumber;

    public Student(String fName, String sName, int indexNumber){
        super( fName, sName);
        this.indexNumber = indexNumber;
    }

    public static void putStudentsToFileZestawA(FileOutputStream fos, Student[] students) throws IOException {
        String output;
        for(int i = 0; i < students.length; i++){
            output  = students[i].getFName() + " ";
            output += students[i].getSName() + " ";
            output += students[i].indexNumber + "\n";

            for(int j=0; j<output.length(); j++) {
                fos.write(output.charAt(j));
            }
        }
    }

    public static Student[] getStudentsFromFileZestawB(FileInputStream fis) throws IOException {
        StringBuffer sb = new StringBuffer();
        int data = fis.read();
        while( data != -1){
            sb.append((char)data);
            data = fis.read();
        }
        String[] studentStrings = sb.toString().split("\n");
        if(studentStrings.length > 8)
            throw new RuntimeException("Too many students");
        Student[] students = new Student[8];
        for(int i=0; i<studentStrings.length; i++){
            String[] parts = studentStrings[i].split(" ");
            students[i] = new Student(
                parts[0], parts[1], Integer.parseInt(parts[2])
            );
        }
        return students;
    }

    public static Student[] getStudentsFromFileZestawC(FileInputStream fis) throws IOException {
        Student[] students = new Student[16];
        int counter = 0;
        int data = fis.read();
        while( data != -1) {
            int indexNumber = 0;
            for (int i = 0; i < 4; i++) {
                indexNumber = indexNumber | (data << (i * 8));
                data = fis.read();
            }
            data = fis.read();
            StringBuffer sb = new StringBuffer();
            while (data != '\n'){
                sb.append((char)data);
                data = fis.read();
            }
            String[] names = sb.toString().split(" ");
            if(counter < students.length)
                students[counter++] = new Student(
                    names[0], names[1], indexNumber
                );
            else
                throw new RuntimeException("Too many students");
            data = fis.read();
        }
        return students;
    }

    //zapis indexów w 4 bitów a potem imie i naziwkso itp
    public static Student[] getStudentsFromFileZestawD(FileInputStream fis) throws IOException {
        Student[] students = new Student[16];
        int counter = 0;
        int data = fis.read();
        while( data != -1) {
            int indexNumber = 0;
            for (int i = 0; i < 4; i++) {
                indexNumber = (indexNumber << 8) | data;
                data = fis.read();
            }
            data = fis.read();
            StringBuffer sb = new StringBuffer();
            while (data != '\n'){
                sb.append((char)data);
                data = fis.read();
            }
            String[] names = sb.toString().split(" ");
            if(counter < students.length)
                students[counter++] = new Student(
                    names[0], names[1], indexNumber
                );
            else
                throw new RuntimeException("Too many students");
            data = fis.read();
        }
        return students;
    }

    //zapis index w formie 4 bitów
    public static void putStudentsToBinFile(FileOutputStream fos, Student[] students) throws IOException {
        for(Student student : students){
            fos.write(student.indexNumber >>24);
            fos.write(student.indexNumber >>16);
            fos.write(student.indexNumber >> 8);
            fos.write(student.indexNumber >> 0);
            fos.write(' ');
            String str = student.getFName() + " " + student.getSName();
            for(char chr : str.toCharArray())
                fos.write(chr);
            fos.write('\n');
        }
    }
}