90%的Java程序员都踩过的内存坑，你还敢说自己稳了吗？

public class HeapDemo {
    public static void main(String[] args) {
        Object obj = new Object(); // 新对象进堆
        List<byte[]> crashList = new ArrayList<>();
        while(true) {
            crashList.add(new byte[1024*1024]); // 每次分配1MB
        }
    }
}

public class StackOverflowDemo {
    static void infiniteLoop() {
        infiniteLoop(); // 无限递归 = 栈爆炸
    }
    public static void main(String[] args) {
        infiniteLoop(); // StackOverflowError
    }
}

Object strongRef = new Object(); // 强引用：不回收
SoftReference<Object> softRef = new SoftReference<>(new Object()); // 内存不足时回收
WeakReference<Object> weakRef = new WeakReference<>(new Object()); // GC时回收
PhantomReference<Object> phantomRef = new PhantomReference<>(new Object(), new ReferenceQueue<>());

static Map<Object, Object> cache = new HashMap<>();
Object key = new Object();
cache.put(key, new byte[1024*1024]);
key = null; // 错误！HashMap还在引用key

ExecutorService pool = Executors.newCachedThreadPool();
while(true) {
    pool.submit(() -> {
        Thread.sleep(1000000);
    });
}