java - 从未调用过序列化方法

Question

我需要从静态 HashMap 序列化数据。我需要这个静态数据，因为我没有该 map 存在的类的实例。我实现了可序列化接口(interface)并构建了这两个方法:

private synchronized void writeObject( ObjectOutputStream out ) throws IOException
{
    System.out.println("start serialization ...");

    Collection<TaskUpdateListener> tasks = listeners.values();
    out.writeInt( tasks.size() );
    for(TaskUpdateListener task : tasks)
    {
        out.writeObject( task );
    }   
}

private synchronized void readObject( ObjectInputStream in ) throws IOException, ClassNotFoundException
{
    System.out.println("start deserialization ...");

    int size = in.readInt();
    for( int index = 0; index < size; index++)
    {
        addTaskUpdateListener( (ComponentScheduleTable) in.readObject() );
    }   
}

但是这个方法永远不会被调用。有没有人遇到同样的问题或解决方案？

Answer 1

尝试

private  void writeObject( ObjectOutputStream out ) throws IOException
    {

        System.out.println("start serialization ...");

        Collection<TaskUpdateListener> tasks = listeners.values();
        out.writeInt( tasks.size() );
        for(TaskUpdateListener task : tasks)
        {
            out.writeObject( task );
        }

  }

Synchronized关键字不是必需的，方法在同步块(synchronized block)中调用。