如何在UDAF中使用第三方不可序列化对象?

时间:2018-07-26 16:43:55

标签: java apache-spark serialization

我有一个具有第三方不可序列化属性的类,需要将其发送给使用此类的一种方法的UDAF。

由于无法序列化的属性,我无法添加“可序列化的实现”,而且我无法进行子类包装,因为该属性需要在其构造函数中使用参数...

有什么主意吗?

public class ClassWithNoSerializableProperty implements Serializable {

    private NoSerializable property;

    public ClassWithNoSerializableProperty (String text) {
        property = new NoSerializable(text);
    }

}
public class NoSerializable {

    protected String text;

    public NoSerializable(String text) {
        this.text = text;
    }

}

1 个答案:

答案 0 :(得分:1)

使用此类包装NoSerializable的构造函数

SerializedWrapper<NoSerializable> property = new SerializedWrapper(() -> new NoSerializable(text));
// call this to use it.
property.get();

/**
 * Makes an unserializable class serializable through lazy initialization.
 */
public class SerializedWrapper<T> implements Serializable {

    private SerializedConstructor<T> constructor;
    private transient T instance;

    /**
     * Creates a serializable wrapper for something.
     */
    public SerializedWrapper(SerializedConstructor<T> constructor) {
        this.constructor = constructor;
    }

    /**
     * Gets or creates an instance of T.
     */
    public T get() {
        if (instance == null){
            instance = constructor.get();
        }
        return instance;
    }

}

/**
 * Dummy interface so we don't have to do (Consumer<T> & Serializable)
 */
public interface SerializedConstructor<T> implements Serializable, Consumer<T> {}