将Java 8功能转换为Java 1.5

interface MyFunction {
    void doSomething();
}

public class Main {
    public static void main(String[] args) {
        MyFunction function = new MyFunction() {
            @Override
            public void doSomething() {
                System.out.println("Hello, world!");
            }
        };
        function.doSomething();
    }
}

import java.util.ArrayList;
import java.util.List;

public class Main {
    public static void main(String[] args) {
        List<Integer> numbers = new ArrayList<>();
        numbers.add(1);
        numbers.add(2);
        numbers.add(3);
        
        for (Integer number : numbers) {
            if (number % 2 == 0) {
                System.out.println(number);
            }
        }
    }
}

import java.util.Calendar;

public class Main {
    public static void main(String[] args) {
        Calendar calendar = Calendar.getInstance();
        System.out.println(calendar.getTime());
    }
}