示例

public static class Object1 implements Externalizable{

private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException {
s.defaultReadObject();
}
}

解决方案
实施 Externalizable 的类应该始终具有带有零参数的构造函数


public static class Object1 implements Externalizable{

private Object1 (){

}

private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException {
s.defaultReadObject();
}
}