存储HashMap< String，Object>与使用ActiveAndroid库 [英] Storing HashMap<String, Object> with using ActiveAndroid library

问题描述

我有一个类：

@Table(name = "Control")
public class Control extends Model{

   @Column
   private String name;

   [...]

   @Column
   private Map<String, Object> properties;

}

我在这个类中有其他字段，只有那些足以显示什么是我的问题。

I have other fields in this class, but i wrote here only those which is enough to show what is my problem.

我有一个关于插入的例外：

I got an exception about insertion:

09-14 22:11:34.542: E/SQLiteLog(11482): (1) table Control has no column named properties

Object可以是String []或String。

Object can be either String[] or String.

如果我没有在HashMap数据上放置@Column，那么一切都是罚款只有他们不存储的问题。

If I dont place @Column on HashMap data, than everything works "fine" only the problem they are not stored.

所以我的问题是我应该如何解决存储这个hashmap。

So my question is how should I solve storing this hashmap.

我的数据来自API，它始终不具有相同的属性：

My data comes from API, and it has not the same properties always:

controls: [
    {
        bundle: "CloseButton",    
        frame: "0,0,25,25"
    },
    {
        referenceKey: "AccelerationGyro",
        name: "Acceleration Sensor",
        bundle: "Gyro",
        properties: {
            axis: "Z"
            observedKey: "brakeState",
            requiedValue: "1"
        },
        channels: {
            CH: "Acceleration"
        }
    },
    {
        referenceKey: "SteeringGyro",
        name: "Steering Sensor",
        bundle: "Gyro",
        properties: {
            axis: "Y"
            allowedOnI: [
                "@Lights",
                "@Rack",
                "@ReversingLamp"
            ],
    },
        channels: {
            CH: "Steering"
    }
},

我想使用ActiveAndroid lib存储这个类。但不幸的是，我找不到任何解决方案，这在网上。

I want to store this class with using ActiveAndroid lib. But unfortunatelly I could not find any solution to this on the web.

我不知道如果我的问题很清楚，我可以提供额外的东西，如果需要。
我只想存储HashMap。 ：P可能是以某种方式连接到TypeSerializers？

I'm not sure if my question is clear, I can provide additional stuff if needed. I just want to store the HashMap too. :P Is it maybe connected somehow to TypeSerializers?

感谢您的回答提前。

推荐答案

ActiveAndroid不会持久映射默认类型。

ActiveAndroid don't persist Map type by default.

您必须自行撰写 TypeSerializer ，才能序列化这个映射为某种格式的字符串（例如：JSON），反序列化为你的 Map 。

Yes, you are right, you must write your own TypeSerializer, to serialize this Map as an String in some format (e.g: JSON) and deserialize the String to your Map.

也许这段代码可以帮助你开始：

Maybe this code can help you to start this:

final public class UtilMapSerializer extends TypeSerializer {
    @Override
    public Class<?> getDeserializedType() {
        return Map.class;
    }

    @Override
    public Class<?> getSerializedType() {
        return String.class;
    }

    @Override
    public String serialize(Object data) {
        if (data == null) {
            return null;
        }

        // Transform a Map<String, Object> to JSON and then to String
        return new JSONObject((Map<String, Object>) data).toString();
    }

    @Override
    public Map<String, Object> deserialize(Object data) {
        if (data == null) {
            return null;
        }

        // Properties of Model
        Map<String, Object> map = new HashMap<String, Object>();

        try {
            JSONObject json = new JSONObject((String) data);

            for(Iterator it = json.keys(); it.hasNext();) {
                String key = (String) it.next();

                map.put(key, json.get(key));
            }

        } catch (JSONException e) {
            e.printStackTrace();
        }

        return map;
    }
}

然后注册为 ;

And register then as <meta-data> in your <Application>.

<meta-data android:name="AA_SERIALIZERS" android:value="my.package.UtilMapSerializer" />

详情：https://github.com/pardom/ActiveAndroid/wiki/Type-serializers

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