JsonJavaMapper.java

/* JsonJavaMapper.java
 *
 * Copyright 2010-2011 Johannes Kepler Universit�t Linz,
 * Institut f�r Wissensbasierte Mathematische Systeme.
 *
 * This file is part of pureImage.
 *
 * pureImage is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * pureImage is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with pureImage. If not, see <http://www.gnu.org/licenses/>.
 */

package pI.generator;

import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonPrimitive;

public class JsonJavaMapper {
	
	public JsonJavaMapper() {
	}
	
	public Object convert(JsonElement root) {
		return json2Java(root);
	}
		
	public Object json2Java(JsonElement elem) {
		if(elem.isJsonArray()) {
			return jsonArrayAsList(elem.getAsJsonArray());
		} else if(elem.isJsonPrimitive()) {
			return json2JavaPrimitive(elem.getAsJsonPrimitive());
		} else {
			return jsonObject2Map(elem.getAsJsonObject());
		}
	}
	
	@SuppressWarnings({"unchecked" })
	public List jsonArrayAsList(JsonArray arr) {
		ArrayList list = new ArrayList(arr.size());
		for (int j = 0; j < arr.size(); j++) {
			list.add(json2Java(arr.get(j)));
		}		
		return list;
	}
	
	
	
	@SuppressWarnings({"unchecked" })
	public Map jsonObject2Map(JsonObject obj) {
		LinkedHashMap map = new LinkedHashMap();
		for(Entry<String, JsonElement> entry: obj.entrySet()) {
			map.put(entry.getKey(), json2Java(entry.getValue()));
		}
		return map;
	}
	
	
	public Object json2JavaPrimitive(JsonPrimitive prim) {
		if(prim.isBoolean()) {
			return prim.getAsBoolean();
		} else if (prim.isString()) {
			return prim.getAsString();
		} else if (prim.isNumber()) {
			return prim.getAsNumber();
		} else {
			throw new IllegalStateException();
		}
	}

}