我有这样的json数据:
meds:
[
{
MedsID: 8063,
updated_at: "2015-11-04T06:59:55",
treatment_date: "2015-11-04T00:00:00",
name: "name"
}
],
scores:
[
{
ScoreID: 75820,
updated_at: "2015-11-04T06:59:55"
dialysis_flow: 233,
}
],
dias:
[
{
DiasID: 75820,
updated_at: "2015-11-04T06:59:55"
name: "K",
}
]
这是我的实体:
public class BaseData{
public long id;
}
public class Med extends BaseData{
public String name;
public String updated_at;
public String treatment_date;
}
public class Score extends BaseData{
public String updated_at;
public int dialysis_flow;
}
public class Dias extends BaseData{
public String name;
public String updated_at;
public String treatment_date;
}
因为所有实体都是使用id
键从数据库映射的(因为我使用的是orm db,它是由属性名称加载的)。因此,在使用gson进行映射时,我需要将所有其他键MedsID
,DiasID
,ScoreID
解析为id
。
有没有办法实现这个目标?
更新:
我使用registerTypeHierarchyAdapter
代替registerTypeAdapter
,它可以正常工作。但这种方式非常慢,因为我的json数据非常大。
public class DataDeserializer implements JsonDeserializer<BaseData> {
@Override
public BaseData deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
JsonObject ja = json.getAsJsonObject();
Gson gson = new Gson();
final String[] mapIds = {"ScoreID", "MedsID", "DiasID"};
BaseData data = gson.fromJson(ja, typeOfT);
for (String idKey:mapIds){
if(ja.has(idKey)){
data.id = ja.get(idKey).getAsLong();
break;
}
}
return data;
}
}
Gson gson = new GsonBuilder().registerTypeHierarchyAdapter( BaseData.class, new DataDeserializer() ).create();
有没有人知道实现这一目标的其他方法?
答案 0 :(得分:1)
实现这一目标的唯一方法是编写自定义反序列化器。请看下面的例子:
public class CustomDeserializer implements JsonDeserializer<Dias>{
public Dias deserialize( JsonElement json, Type typeOfT, JsonDeserializationContext context ) throws JsonParseException{
JsonObject ja = json.getAsJsonObject();
Dias dias = new Gson().fromJson( ja, Dias.class );
dias.id = ja.get( "DiasID" ).getAsLong();
return dias;
}
}
注册;
String dias = "{'DiasID':75820,'updated_at':'2015-11-04T06:59:55','name':'K'}";
Gson gson = new GsonBuilder().registerTypeAdapter( Dias.class, new CustomDeserializer() ).create();
Dias dias2 = gson.fromJson( dias, Dias.class );
System.out.println( dias2.id );
输出:
75820
这只是一个示例,您可以通过为自己的基类编写反序列化来扩展它。