com.foobnix.vkontakte.VkGsonResponse.java Source code

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Here is the source code for com.foobnix.vkontakte.VkGsonResponse.java

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/* Copyright (c) 2011 Ivan Ivanenko <ivan.ivanenko@gmail.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE. */
package com.foobnix.vkontakte;

import java.util.ArrayList;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.foobnix.exception.VkErrorException;
import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonParser;

public class VkGsonResponse {
    private final static Log log = LogFactory.getLog(VkGsonResponse.class);

    public static <T> List<T> toModels(String json, Class<T> clazz) throws VkErrorException {
        return toModels(json, clazz, 1);
    }

    public static <T> List<T> toModels(String json, Class<T> clazz, int startIndex) throws VkErrorException {
        List<T> result = new ArrayList<T>();

        if (json == null || json.trim().isEmpty() || json.trim().equalsIgnoreCase("{\"response\":{}}")) {
            log.debug("Recive an empty json" + json);
            return result;
        }
        if (json.trim().startsWith("{\"error\":")) {
            throw new VkErrorException(json);
        }

        Gson gson = new Gson();
        JsonParser parser = new JsonParser();
        JsonArray array = parser.parse(json).getAsJsonObject().getAsJsonArray("response");

        for (int i = startIndex; i < array.size(); i++) {
            JsonElement next = array.get(i);
            T fromJson = gson.fromJson(next, clazz);
            result.add(fromJson);
        }
        return result;
    }

}