如何保持对象的弱引用？

import java.lang.ref.WeakReference;

public class Main {
    public static void main(String[] args) {
        // 创建一个弱引用
        WeakReference<MyObject> weakReference = new WeakReference<>(new MyObject());

        // 通过弱引用获取对象
        MyObject myObject = weakReference.get();

        // 使用对象
        if (myObject != null) {
            myObject.doSomething();
        }
    }

    static class MyObject {
        void doSomething() {
            System.out.println("Do something...");
        }
    }
}