class User implements Serializable {
    private String username;
    private transient String password;
}

import java.lang.reflect.Method;

public class ReflectionExample {
    public static void main(String[] args) throws Exception {
        // Класс, который будем исследовать
        Class<?> clazz = Class.forName("java.lang.String");

        Method[] methods = clazz.getDeclaredMethods();

        for (Method method : methods) {
            System.out.println("Метод: " + method.getName());
        }
    }
}

String strongRef = new String("Strong Reference");

SoftReference<String> softRef = new SoftReference<>(new String("Soft Reference"));
String softObj = softRef.get();

WeakReference<String> weakRef = new WeakReference<>(new String("Weak Reference"));
String weakObj = weakRef.get();

PhantomReference<String> phantomRef = new PhantomReference<>(new String("Phantom Reference"), new ReferenceQueue<>());

@Override
public int compareTo(Person other) {
    return Integer.compare(this.age, other.age);
}

Comparator<Person> byName = (p1, p2) -> p1.getName().compareTo(p2.getName());

Proglib рассказывает про любимый язык програмирования в формате рилса

public class Service {
    private final Repository repository;

    public Service(Repository repository) {
        this.repository = repository;
    }
}

public class Service {
    private Repository repository;

    public void setRepository(Repository repository) {
        this.repository = repository;
    }
}

@Component
public class Service {
    @Autowired
    private Repository repository;
}