Java 기능의 메모리 사용량을 측정하고 최적화하는 방법은 무엇입니까?

import java.lang.management.ManagementFactory;

public class MemoryUsageExample {

    public static void main(String[] args) {
        long heapSize = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage().getUsed();
        System.out.println("Used heap memory: " + heapSize + " bytes");
    }
}

// 使用原始类型
int[] numbers = new int[] { 1, 2, 3 };

// 使用引用类型
ArrayList<Integer> numbers = new ArrayList<>();
numbers.add(1);
numbers.add(2);
numbers.add(3);

public class MemoryLeakExample {

    public static void main(String[] args) {
        ArrayList<Object> list = new ArrayList<>();

        for (int i = 0; i < 10000; i++) {
            list.add(new Object());
        }

        // 未释放列表中的引用
    }
}

import java.util.concurrent.ConcurrentHashMap;

public class ObjectPoolExample {

    private static ConcurrentHashMap<Class<?>, Object> pool = new ConcurrentHashMap<>();

    public static <T> T get(Class<T> type) {
        return (T) pool.computeIfAbsent(type, t -> new Object());
    }

    public static void release(Object object) {
        pool.remove(object.getClass());
    }
}

import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.LongStream;

public class AverageCalculator {

    public static double calculateAverage(List<Long> numbers) {
        // 使用引用类型并避免内存泄漏
        List<Long> uniqueNumbers = numbers.stream().distinct().collect(Collectors.toList());

        return uniqueNumbers.stream().reduce(0L, Long::sum) / uniqueNumbers.size();
    }

    public static void main(String[] args) {
        List<Long> numbers = LongStream.range(0, 1000000).boxed().toList();
        // 使用 JMX 衡量内存使用
        long before = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage().getUsed();
        double average = calculateAverage(numbers);
        long after = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage().getUsed();
        // 计算内存消耗
        System.out.println("Memory consumed: " + (after - before) + " bytes");
        System.out.println("Average: " + average);
    }
}