Fayllar va kirish-chiqish

import java.nio.file.*;

public class Yollar {
    public static void main(String[] args) {
        Path yol = Path.of("hujjatlar", "hisobot", "2026-yil.txt");

        System.out.println("To'liq yo'l:  " + yol);
        System.out.println("Fayl nomi:    " + yol.getFileName());
        System.out.println("Papka:        " + yol.getParent());
        System.out.println("Qismlar soni: " + yol.getNameCount());
        System.out.println("Mutlaqmi:     " + yol.isAbsolute());
        System.out.println("Qo'shilgan:   " + yol.resolveSibling("eski.txt"));
    }
}

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.*;

public class Matn {
    public static void main(String[] args) throws IOException {
        Path yol = Files.createTempFile("sinov", ".txt");

        Files.writeString(yol, "Birinchi qator\nIkkinchi qator",
                StandardCharsets.UTF_8);

        String matn = Files.readString(yol, StandardCharsets.UTF_8);
        System.out.println("Uzunligi: " + matn.length());
        System.out.println(matn);

        System.out.println("Mavjudmi: " + Files.exists(yol));
        Files.delete(yol);
        System.out.println("O'chirilgach: " + Files.exists(yol));
    }
}

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.*;
import java.util.List;

public class Qatorlar {
    public static void main(String[] args) throws IOException {
        Path yol = Files.createTempFile("shaharlar", ".txt");

        Files.write(yol, List.of("Namangan", "Andijon", "Samarqand"),
                StandardCharsets.UTF_8);

        List<String> qatorlar =
                Files.readAllLines(yol, StandardCharsets.UTF_8);
        System.out.println(qatorlar.size() + " ta qator:");
        for (int i = 0; i < qatorlar.size(); i++) {
            System.out.println("  " + (i + 1) + ". " + qatorlar.get(i));
        }

        Files.writeString(yol, "Toshkent\n", StandardCharsets.UTF_8,
                StandardOpenOption.APPEND);
        System.out.println("Qo'shilgach: "
                + Files.readAllLines(yol, StandardCharsets.UTF_8).size()
                + " ta");

        Files.delete(yol);
    }
}

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.*;
import java.util.List;
import java.util.stream.Stream;

public class OqimBilan {
    public static void main(String[] args) throws IOException {
        Path yol = Files.createTempFile("ballar", ".txt");
        Files.write(yol, List.of("92", "78", "85", "", "95", "64"),
                StandardCharsets.UTF_8);

        try (Stream<String> qatorlar =
                     Files.lines(yol, StandardCharsets.UTF_8)) {
            var statistika = qatorlar
                    .filter(q -> !q.isBlank())
                    .mapToInt(Integer::parseInt)
                    .summaryStatistics();

            System.out.println("Soni:     " + statistika.getCount());
            System.out.println("Yig'indi: " + statistika.getSum());
            System.out.println("Eng past: " + statistika.getMin());
            System.out.println("Eng yuqori: " + statistika.getMax());
        }

        Files.delete(yol);
    }
}

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.*;
import java.util.stream.Stream;

public class Kataloglar {
    public static void main(String[] args) throws IOException {
        Path asos = Files.createTempDirectory("sinov");
        Path ichki = asos.resolve("ichki");
        Files.createDirectories(ichki);

        Files.writeString(asos.resolve("a.txt"), "a", StandardCharsets.UTF_8);
        Files.writeString(asos.resolve("b.txt"), "bb",
                StandardCharsets.UTF_8);
        Files.writeString(ichki.resolve("c.txt"), "ccc",
                StandardCharsets.UTF_8);

        try (Stream<Path> yuza = Files.list(asos)) {
            System.out.println("Faqat asosda: " + yuza.count() + " ta");
        }

        try (Stream<Path> chuqur = Files.walk(asos)) {
            long fayllar = chuqur.filter(Files::isRegularFile).count();
            System.out.println("Barcha fayllar: " + fayllar + " ta");
        }

        System.out.println("a.txt hajmi: "
                + Files.size(asos.resolve("a.txt")) + " bayt");
        System.out.println("Katalogmi: " + Files.isDirectory(ichki));

        ochir(asos);
        System.out.println("O'chirilgach mavjudmi: " + Files.exists(asos));
    }

    static void ochir(Path yol) throws IOException {
        try (Stream<Path> hammasi = Files.walk(yol)) {
            for (Path p : hammasi.sorted((a, b) -> b.compareTo(a)).toList()) {
                Files.delete(p);
            }
        }
    }
}

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.*;
import java.util.*;
import java.util.stream.*;

public class Csv {
    public static void main(String[] args) throws IOException {
        Path yol = Files.createTempFile("jurnal", ".csv");
        Files.write(yol, List.of(
                "ism,ball,guruh",
                "Husanboy,92,A",
                "Malika,78,B",
                "Nodira,85,A"), StandardCharsets.UTF_8);

        List<Talaba> talabalar;
        try (Stream<String> qatorlar =
                     Files.lines(yol, StandardCharsets.UTF_8)) {
            talabalar = qatorlar
                    .skip(1)
                    .map(q -> q.split(","))
                    .map(q -> new Talaba(q[0], Integer.parseInt(q[1]), q[2]))
                    .toList();
        }

        talabalar.forEach(System.out::println);

        Map<String, Double> ortacha = talabalar.stream()
                .collect(Collectors.groupingBy(Talaba::guruh, TreeMap::new,
                        Collectors.averagingInt(Talaba::ball)));
        System.out.println("Guruh o'rtachasi: " + ortacha);

        Files.delete(yol);
    }
}

record Talaba(String ism, int ball, String guruh) {
}

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.*;

public class Xatolar {
    public static void main(String[] args) {
        Path yoq = Path.of("bunday-fayl-yoq-12345.txt");

        try {
            Files.readString(yoq, StandardCharsets.UTF_8);
        } catch (NoSuchFileException x) {
            System.out.println("Fayl topilmadi: " + x.getFile());
        } catch (IOException x) {
            System.out.println("Kirish-chiqish xatosi: " + x.getMessage());
        }

        System.out.println("Mavjudmi: " + Files.exists(yoq));
        System.out.println("O'qish mumkinmi: " + Files.isReadable(yoq));
    }
}