Android之基于Gson的ParameterizedType进行泛型解析

class GsonResponsePasare<T> {
    T deal(String response) {
        Type gsonType = new TypeToken<CommonResponse<T>>() {
        }.getType();
        CommonResponse<T> commonResponse = new Gson().fromJson(response, gsonType);
        lg.e("Data is : " + commonResponse.data, "Class Type is : " + commonResponse.data.getClass().toString());
        return commonResponse.data;
    }
}

class CommonResponse<T> {
    int status;
    T data;
}

String strResult = new GsonResponsePasare<String>().deal("{\"status\":-4,\"data\":\"xiaoxuan948\"}");
lg.e("StringResult:" + strResult);

class DataInfo {
    String name;
}

DataInfo dataInfoResult = new GsonResponsePasare<DataInfo>().deal("{\"status\":-4,\"data\":{\"name\":\"xiaoxuan948\"}}");
lg.e("DataInfo:" + dataInfoResult.toString(), "Value:" + dataInfoResult.name);

List<DataInfo> resultList = new GsonResponsePasare<List<DataInfo>>().deal("{\"status\":-4,\"data\":[{\"name\":\"xiaoxuan948\"},{\"name\":\"coca\"}]}");
for (DataInfo entity : resultList) {
    lg.e("DataInfo:" + entity.toString(), "Value:" + entity.name);
}

class GsonResponsePasare<T> implements ParameterizedType {
        private final UtilsLog lg = UtilsLog.getLogger(GsonResponsePasare.class);

        public T deal(String response) {
//            Type gsonType = new ParameterizedType() {//...};//不建议该方式，推荐采用GsonResponsePasare实现ParameterizedType.因为getActualTypeArguments这里涉及获取GsonResponsePasare的泛型集合
            Type gsonType = this;

            CommonResponse<T> commonResponse = new Gson().fromJson(response, gsonType);
            lg.e("Data is : " + commonResponse.data, "Class Type is : " + commonResponse.data.getClass().toString());
            return commonResponse.data;
        }

        @Override
        public Type[] getActualTypeArguments() {
            Class clz = this.getClass();
            //这里必须注意在外面使用new GsonResponsePasare<GsonResponsePasare.DataInfo>(){};实例化时必须带上{},否则获取到的superclass为Object
            Type superclass = clz.getGenericSuperclass(); //getGenericSuperclass()获得带有泛型的父类
            if (superclass instanceof Class) {
                throw new RuntimeException("Missing type parameter.");
            }
            ParameterizedType parameterized = (ParameterizedType) superclass;
            return parameterized.getActualTypeArguments();
        }

        @Override
        public Type getOwnerType() {
            return null;
        }

        @Override
        public Type getRawType() {
            return CommonResponse.class;
        }
    }

List<DataInfo> resultList = new GsonResponsePasare<List<DataInfo>>() {
}.deal("{\"status\":-4,\"data\":[{\"name\":\"xiaoxuan948\"},{\"name\":\"coca\"}]}");
for (DataInfo entity : resultList) {
    lg.e("DataInfo:" + entity.toString(), "Value:" + entity.name);
}

GsonResponsePasare<DataInfo> pasare = new GsonResponsePasare<DataInfo>() {
};
DataInfo dataInfoResult = pasare.deal("{\"status\":-4,\"data\":{\"name\":\"xiaoxuan948\"}}");
lg.e("DataInfo:" + dataInfoResult.toString(), "Value:" + dataInfoResult.name);

java.lang.IllegalArgumentException
at com.google.gson.internal.$Gson$Preconditions.checkArgument($Gson$Preconditions.java:46)
at com.google.gson.internal.$Gson$Types$ParameterizedTypeImpl.<init>($Gson$Types.java:448)
at com.google.gson.internal.$Gson$Types.canonicalize($Gson$Types.java:103)
at com.google.gson.reflect.TypeToken.<init>(TypeToken.java:72)
at com.google.gson.reflect.TypeToken.get(TypeToken.java:296)
at com.google.gson.Gson.fromJson(Gson.java:877)
at com.google.gson.Gson.fromJson(Gson.java:844)
at com.google.gson.Gson.fromJson(Gson.java:793)...