// Чтение из файла
try (FileInputStream fis = new FileInputStream("input.txt")) {
    int data;
    while ((data = fis.read()) != -1) {
        System.out.print((char) data);
    }
} catch (IOException e) {
    e.printStackTrace();
}

// Запись в файл
try (FileOutputStream fos = new FileOutputStream("output.txt")) {
    String text = "Hello, World!";
    fos.write(text.getBytes());
} catch (IOException e) {
    e.printStackTrace();
}

// Чтение из файла
try (BufferedReader br = new BufferedReader(new FileReader("input.txt"))) {
    String line;
    while ((line = br.readLine()) != null) {
        System.out.println(line);
    }
} catch (IOException e) {
    e.printStackTrace();
}

// Запись в файл
try (BufferedWriter bw = new BufferedWriter(new FileWriter("output.txt"))) {
    String text = "Hello, World!";
    bw.write(text);
} catch (IOException e) {
    e.printStackTrace();
}

File file = new File("example.txt");

boolean exists = file.exists();

boolean created = file.createNewFile();

boolean deleted = file.delete();

String name = file.getName();

String path = file.getPath();

String absolutePath = file.getAbsolutePath();

boolean isDirectory = file.isDirectory();

File[] files = file.listFiles();
for (File f : files) {
    System.out.println(f.getName());
}

File file = new File("example.txt");

// Проверка существования файла
if (!file.exists()) {
    // Создание нового файла
    try {
        boolean created = file.createNewFile();
        if (created) {
            System.out.println("File created successfully.");
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}

// Получение информации о файле
System.out.println("File name: " + file.getName());
System.out.println("File path: " + file.getPath());
System.out.println("Absolute path: " + file.getAbsolutePath());
System.out.println("Is directory: " + file.isDirectory());

// Удаление файла
boolean deleted = file.delete();
if (deleted) {
    System.out.println("File deleted successfully.");
}

Path path = Paths.get("example.txt");

Path fileName = path.getFileName();

Path parent = path.getParent();

Path root = path.getRoot();

boolean exists = Files.exists(path);

Files.createFile(path);

Files.delete(path);

BasicFileAttributes attrs = Files.readAttributes(path, BasicFileAttributes.class);

Path path = Paths.get("example.txt");

// Проверка существования файла
if (!Files.exists(path)) {
    // Создание нового файла
    try {
        Path createdFilePath = Files.createFile(path);
        System.out.println("File created at path: " + createdFilePath);
    } catch (IOException e) {
        e.printStackTrace();
    }
}

// Получение информации о файле
System.out.println("File name: " + path.getFileName());
System.out.println("Parent path: " + path.getParent());
System.out.println("Root path: " + path.getRoot());

// Удаление файла
try {
    Files.delete(path);
    System.out.println("File deleted successfully.");
} catch (IOException e) {
    e.printStackTrace();
}

import java.io.FileReader;
import java.io.IOException;

public class FileReaderExample {
    public static void main(String[] args) {
        try (FileReader reader = new FileReader("example.txt")) {
            int character;
            while ((character = reader.read()) != -1) {
                System.out.print((char) character);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

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

public class FileWriterExample {
    public static void main(String[] args) {
        try (FileWriter writer = new FileWriter("example.txt")) {
            writer.write("Hello, World!");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class BufferedReaderExample {
    public static void main(String[] args) {
        try (BufferedReader reader = new BufferedReader(new FileReader("example.txt"))) {
            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

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

public class BufferedWriterExample {
    public static void main(String[] args) {
        try (BufferedWriter writer = new BufferedWriter(new FileWriter("example.txt"))) {
            writer.write("Hello, World!");
            writer.newLine();
            writer.write("This is an example of BufferedWriter.");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

public class InputStreamExample {
    public static void main(String[] args) {
        try (InputStream inputStream = new FileInputStream("example.bin")) {
            int data;
            while ((data = inputStream.read()) != -1) {
                System.out.print((char) data);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

public class OutputStreamExample {
    public static void main(String[] args) {
        try (OutputStream outputStream = new FileOutputStream("example.bin")) {
            String data = "Hello, World!";
            outputStream.write(data.getBytes());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

public class BufferedInputStreamExample {
    public static void main(String[] args) {
        try (InputStream inputStream = new BufferedInputStream(new FileInputStream("example.bin"))) {
            int data;
            while ((data = inputStream.read()) != -1) {
                System.out.print((char) data);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

public class BufferedOutputStreamExample {
    public static void main(String[] args) {
        try (OutputStream outputStream = new BufferedOutputStream(new FileOutputStream("example.bin"))) {
            String data = "Hello, World!";
            outputStream.write(data.getBytes());
            outputStream.flush();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.io.Serializable;

class Person implements Serializable {
    private static final long serialVersionUID = 1L;
    private String name;
    private int age;

    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    @Override
    public String toString() {
        return "Person{name='" + name + "', age=" + age + '}';
    }
}

public class ObjectOutputStreamExample {
    public static void main(String[] args) {
        Person person = new Person("John Doe", 30);

        try (ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("person.ser"))) {
            oos.writeObject(person);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import java.io.FileInputStream;
import java.io.IOException;
import java.io.ObjectInputStream;

public class ObjectInputStreamExample {
    public static void main(String[] args) {
        try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream("person.ser"))) {
            Person person = (Person) ois.readObject();
            System.out.println(person);
        } catch (IOException | ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
}

import java.io.Serializable;

class Person implements Serializable {
    private static final long serialVersionUID = 1L;
    private String name;
    private int age;

    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    @Override
    public String toString() {
        return "Person{name='" + name + "', age=" + age + '}';
    }
}

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;

public class SerializationExample {
    public static void main(String[] args) {
        Person person = new Person("John Doe", 30);

        try (ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("person.ser"))) {
            oos.writeObject(person);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import java.io.FileInputStream;
import java.io.IOException;
import java.io.ObjectInputStream;

public class DeserializationExample {
    public static void main(String[] args) {
        try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream("person.ser"))) {
            Person person = (Person) ois.readObject();
            System.out.println(person);
        } catch (IOException | ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
}

class Person implements Serializable {
    private static final long serialVersionUID = 1L;
    // остальные поля и методы
}

class User implements Serializable {
    private static final long serialVersionUID = 1L;
    private String username;
    private transient String password;

    public User(String username, String password) {
        this.username = username;
        this.password = password;
    }

    @Override
    public String toString() {
        return "User{username='" + username + "', password='" + password + "'}";
    }
}

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class BufferedReaderExample {
    public static void main(String[] args) {
        try (BufferedReader reader = new BufferedReader(new FileReader("example.txt"))) {
            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.util.Iterator;

public class NIOServer {
    public static void main(String[] args) throws IOException {
        Selector selector = Selector.open();
        ServerSocketChannel serverChannel = ServerSocketChannel.open();
        serverChannel.bind(new InetSocketAddress("localhost", 8080));
        serverChannel.configureBlocking(false);
        serverChannel.register(selector, SelectionKey.OP_ACCEPT);

        ByteBuffer buffer = ByteBuffer.allocate(1024);

        while (true) {
            selector.select();
            Iterator<SelectionKey> keys = selector.selectedKeys().iterator();

            while (keys.hasNext()) {
                SelectionKey key = keys.next();
                keys.remove();

                if (key.isAcceptable()) {
                    SocketChannel client = serverChannel.accept();
                    client.configureBlocking(false);
                    client.register(selector, SelectionKey.OP_READ);
                } else if (key.isReadable()) {
                    SocketChannel client = (SocketChannel) key.channel();
                    buffer.clear();
                    int bytesRead = client.read(buffer);
                    if (bytesRead == -1) {
                        client.close();
                    } else {
                        buffer.flip();
                        client.write(buffer);
                    }
                }
            }
        }
    }
}

import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousFileChannel;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import java.util.concurrent.Future;

public class AsyncFileRead {
    public static void main(String[] args) throws Exception {
        Path path = Paths.get("example.txt");
        AsynchronousFileChannel fileChannel = AsynchronousFileChannel.open(path, StandardOpenOption.READ);
        ByteBuffer buffer = ByteBuffer.allocate(1024);

        Future<Integer> result = fileChannel.read(buffer, 0);
        while (!result.isDone()) {
            System.out.println("Waiting for read operation...");
            Thread.sleep(100);
        }

        buffer.flip();
        byte[] data = new byte[buffer.limit()];
        buffer.get(data);
        System.out.println(new String(data));
        fileChannel.close();
    }
}