java序列化

https://www.hollischuang.com/archives/1140#What Serializable Did

ObjectOutputStream objectOutputStream = new ObjectOutputStream(new FileOutputStream("stringlist"));
objectOutputStream.writeObject(stringList);

objectOutputStream.writeObject()最终会通过反射调用stringList的writeObject（）方法，如果没有实现writeObject（），则
调用默认的ObjectOutputStream 的 defaultWriteObject 方法以及 ObjectInputStream 的 defaultReadObject 方法。

private void readObject(java.io.ObjectInputStream s)
        throws java.io.IOException, ClassNotFoundException {
        elementData = EMPTY_ELEMENTDATA;

        // Read in size, and any hidden stuff
        s.defaultReadObject();

        // Read in capacity
        s.readInt(); // ignored

        if (size > 0) {
            // be like clone(), allocate array based upon size not capacity
            ensureCapacityInternal(size);

            Object[] a = elementData;
            // Read in all elements in the proper order.
            for (int i=0; i<size; i++) {
                a[i] = s.readObject();
            }
        }
    }