有没有办法禁用ORMLite的检查，用DataType.SERIALIZABLE声明的字段实现Serializable？ [英] Is there any way to disable ORMLite's check that a field declared with DataType.SERIALIZABLE implements Serializable?

问题描述

问题标题只是说这一切。我有一个字段声明如下：

Question title just about says it all. I have a field declared like this:

    @DatabaseField(canBeNull=false,dataType=DataType.SERIALIZABLE)
    List<ScheduleTriggerPredicate> predicates = Collections.emptyList();

根据上下文，谓词空列表或由 Collections.unmodifiableList（List）以 ArrayList 作为其参数返回的不可变列表。我因此知道有问题的对象是可序列化的，但没有办法我可以告诉编译器（因此ORMLite），它是。因此，我得到这个异常：

Depending on context, predicates can either contain the empty list or an immutable list returned by Collections.unmodifiableList(List) with an ArrayList as its parameter. I therefore know that the object in question is serializable, but there is no way I can tell the compiler (and therefore ORMLite) that it is. Therefore I get this exception:

SEVERE: Servlet /ADHDWeb threw load() exception
java.lang.IllegalArgumentException: Field class java.util.List for field
    FieldType:name=predicates,class=ScheduleTrigger is not valid for type 
    com.j256.ormlite.field.types.SerializableType@967d5f, maybe should be
    interface java.io.Serializable

现在，如果只有一些方法禁用检查，一切都会很好...

Now, if there was just some way of disabling the check, everything would obviously work fine...

推荐答案

定义自定义数据类型在FM中有很好的文档：

Defining a custom data type is pretty well documented in the FM:

http://ormlite.com/docs/ custom-data-types

您可以扩展 SerializableType 类和 @Override 方法。 isValidForField（...）在这种情况下，这将序列化集合。

You can extend the the SerializableType class and @Override the isValidForField(...) method. In this case, this will serialize collections.

public class SerializableCollectionsType extends SerializableType {
    private static LocalSerializableType singleton;
    public SerializableCollectionsType() {
        super(SqlType.SERIALIZABLE, new Class<?>[0]);
    }
    public static LocalSerializableType getSingleton() {
        if (singleton == null) {
            singleton = new LocalSerializableType();
        }
        return singleton;
    }
    @Override
    public boolean isValidForField(Field field) {
        return Collection.class.isAssignableFrom(field.getType());
    }
}

要使用此功能，您必须替换<$ c $在 @DatabaseField 中使用 persisterClass 的c> dataType ：

To use this you must replace the dataType with persisterClass in @DatabaseField:

@DatabaseField(canBeNull = false,
    persisterClass = SerializableCollectionsType.class)
List<ScheduleTriggerPredicate> predicates = Collections.emptyList();

我添加了单元测试来显示工作代码。这是 github更改。

I've added to the unit test to show working code with this. Here's the github change.

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