import java.io.*;

class User implements Serializable {
    private String username;
    private transient String password; // ذخیره نمی‌شود 🚫

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

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

public class Main {
    public static void main(String[] args) throws Exception {
        User user = new User("Saleh", "12345");

        // Serialize
        ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("user.ser"));
        oos.writeObject(user);
        oos.close();

        // Deserialize
        ObjectInputStream ois = new ObjectInputStream(new FileInputStream("user.ser"));
        User deserializedUser = (User) ois.readObject();
        ois.close();

        System.out.println("بعد از Deserialize:");
        System.out.println(deserializedUser); 
        // password = null چون transient بوده
    }
}

import java.io.*;

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

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

#کاربرـحرفهـای

🆔 @javapro_ir
🆔 @group_javapro

private void writeObject(ObjectOutputStream out) throws IOException
private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException

import java.io.*;

class User implements Serializable {
    private String username;
    private transient String password; // ذخیره مستقیم نمی‌شود ❌

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

    private void writeObject(ObjectOutputStream out) throws IOException {
        out.defaultWriteObject(); // فیلدهای عادی رو ذخیره کن
        String encryptedPassword = "ENC(" + password + ")"; 
        out.writeObject(encryptedPassword); // رمزنگاری ساده (نمونه آموزشی)
    }

    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
        in.defaultReadObject(); // فیلدهای عادی رو بخون
        String encryptedPassword = (String) in.readObject();
        this.password = encryptedPassword.replace("ENC(", "").replace(")", ""); // رمزگشایی ساده
    }

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

public class Main {
    public static void main(String[] args) throws Exception {
        User user = new User("Saleh", "12345");

        // Serialize
        ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("user.ser"));
        oos.writeObject(user);
        oos.close();

        // Deserialize
        ObjectInputStream ois = new ObjectInputStream(new FileInputStream("user.ser"));
        User deserializedUser = (User) ois.readObject();
        ois.close();

        System.out.println("بعد از Deserialize:");
        System.out.println(deserializedUser); 
    }
}

#کاربرـحرفهـای

🆔 @javapro_ir
🆔 @group_javapro

class Outer {
    private String message = "Hello from Outer!";

    class Inner {
        void printMessage() {
            System.out.println(message); // دسترسی مستقیم به فیلد Outer
        }
    }
}

public class Main {
    public static void main(String[] args) {
        Outer outer = new Outer();
        Outer.Inner inner = outer.new Inner(); // ساخت inner class
        inner.printMessage();
    }
}

class Outer {
    static class Nested {
        void display() {
            System.out.println("Static Nested Class");
        }
    }
}

public class Main {
    public static void main(String[] args) {
        Outer.Nested nested = new Outer.Nested(); // بدون نیاز به instance از Outer
        nested.display();
    }
}

interface Greeting {
    void sayHello();
}

public class Main {
    public static void main(String[] args) {
        Greeting g = new Greeting() {
            @Override
            public void sayHello() {
                System.out.println("Hello from Anonymous Inner Class!");
            }
        };
        g.sayHello();
    }
}

#کاربرـپیشرفته

🆔 @javapro_ir
🆔 @group_javapro

interface Greeting {
    void sayHello();
}

public class Main {
    public static void main(String[] args) {
        Greeting g = new Greeting() {
            @Override
            public void sayHello() {
                System.out.println("Hello from Anonymous Class");
            }
        };
        g.sayHello();
    }
}

interface Greeting {
    void sayHello();
}

public class Main {
    public static void main(String[] args) {
        Greeting g = () -> System.out.println("Hello from Lambda");
        g.sayHello();
    }
}

interface Printer {
    void print();
}

public class Main {
    public void test() {
        // Anonymous Inner Class
        Printer p1 = new Printer() {
            @Override
            public void print() {
                System.out.println(this.getClass().getName());
            }
        };
        p1.print();

        // Lambda
        Printer p2 = () -> {
            System.out.println(this.getClass().getName());
        };
        p2.print();
    }

    public static void main(String[] args) {
        new Main().test();
    }
}

#کاربرـحرفهـای

🆔 @javapro_ir
🆔 @group_javapro

public class ClosureExample {
    public static void main(String[] args) {
        String greeting = "Hello";

        Runnable r = () -> {
            System.out.println(greeting + ", Lambda!");
        };

        r.run();
    }
}

public class ClosureError {
    public static void main(String[] args) {
        int counter = 0;

        Runnable r = () -> {
            // خطا: چون counter بعداً تغییر داده می‌شه
            System.out.println(counter);
        };

        counter++; //  این باعث می‌شه متغیر دیگه effectively final نباشه
    }
}

public class ClosureCorrect {
    public static void main(String[] args) {
        final int counter = 0;

        Runnable r = () -> {
            System.out.println(counter);
        };

        r.run(); //  بدون خطا
    }
}

#کاربرـپیشرفته

🆔 @javapro_ir
🆔 @group_javapro

import java.util.concurrent.CompletableFuture;

public class AsyncExample {
    public static void main(String[] args) {
        CompletableFuture<Void> future = CompletableFuture.runAsync(() -> {
            // یه تسک ساده
            System.out.println("در حال اجرا در یک Thread جداگانه: " + Thread.currentThread().getName());
        });

        // منتظر می‌مونیم تا کار تموم بشه
        future.join();

        System.out.println("کار اصلی تمام شد!");
    }
}

import java.util.concurrent.CompletableFuture;

public class SupplyExample {
    public static void main(String[] args) {
        CompletableFuture<String> future = CompletableFuture.supplyAsync(() -> {
            return "Hello from Async Task!";
        });

        // گرفتن نتیجه
        String result = future.join();
        System.out.println("نتیجه: " + result);
    }
}

import java.util.concurrent.CompletableFuture;

public class CombineExample {
    public static void main(String[] args) {
        CompletableFuture<String> future1 = CompletableFuture.supplyAsync(() -> "Java");
        CompletableFuture<String> future2 = CompletableFuture.supplyAsync(() -> "Async");

        CompletableFuture<String> combined = future1.thenCombine(future2, (f1, f2) -> f1 + " " + f2);

        System.out.println(combined.join()); // خروجی: Java Async
    }
}

#کاربرـحرفهـای

🆔 @javapro_ir
🆔 @group_javapro