GsonUtil.java

/*
 * Copyright 2015 Evgeny Dolganov (evgenij.dolganov@gmail.com).
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package och.util.json;

import static och.util.DateUtil.*;
import static och.util.Util.*;

import java.lang.reflect.Array;
import java.util.Collections;
import java.util.List;

import och.util.Util;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;


public class GsonUtil {
	
	public static final Gson defaultGson = gsonWithFullDateFormat();
	public static final Gson defaultGsonPrettyPrinting = gsonWithFullDateFormat(true);
	
	public static <T> List<T> getList(String content, Class<T> type){
		return getList(content, type, new Gson());
	}
	
	@SuppressWarnings("unchecked")
	public static <T> List<T> getList(String content, Class<T> type, Gson gson){
		
		if(Util.isEmpty(content)){
			return Collections.emptyList();
		}
		
		Object arrayObject = Array.newInstance(type,0);
        T[] data = (T[]) gson.fromJson(content, arrayObject.getClass());
        List<T> out = list(data);
        return out;
	}
	
	
	public static Gson gsonWithFullDateFormat(){
		return gsonWithFullDateFormat(false);
	}
	
	public static Gson gsonWithFullDateFormat(boolean prettyPrinting){
		return gsonWithDateFormat(FULL_DATE_FORMAT, prettyPrinting);
	}
	
	public static Gson gsonWithDateFormat(String dateFormat, boolean prettyPrinting){
		GsonBuilder builder = new GsonBuilder();
		builder.setDateFormat(dateFormat);
		if(prettyPrinting) builder.setPrettyPrinting();
		return builder.create();
	}

}