JUniformPackerJSON.java

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package com.juniform;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.JSONValue;
import org.json.simple.parser.ParseException;

/**
 * Class that converts from JUniformObject to JSONValue and back
 * @author acherkashin
 */
public class JUniformPackerJSON implements IJUniformPacker
{
	// ---------------------------------------------------------------------- //
	// PUBLIC
	// ---------------------------------------------------------------------- //
	
	@Override
	public JUniformObject toUniformObjectFromStream(InputStream stream) {
		try (InputStreamReader inputStreamReader = new InputStreamReader(stream)) {
			Object value = JSONValue.parseWithException(inputStreamReader);
			return this.toUniformObjectFromObject(value);
		}
		catch(IOException | ParseException ex) {
			return JUniformObject.OBJECT_NIL;
		}
	}
	
	@Override
	public JUniformObject toUniformObjectFromString(String string) {
		try {
			Object value = JSONValue.parseWithException(string);
			return this.toUniformObjectFromObject(value);
		} catch(ParseException ex) {
			return JUniformObject.OBJECT_NIL;
		}
	}
	
	@Override
	public JUniformObject toUniformObjectFromBytes(byte[] bytes) {
		ByteBuffer buffer = ByteBuffer.wrap(bytes);
		return this.toUniformObjectFromString(Charset.defaultCharset().decode(buffer).toString());
	}
	
	@Override
	public JUniformObject toUniformObjectFromObject(Object object) {
		if (object == null) {
			return JUniformObject.OBJECT_NIL;
		} else if (object instanceof JSONObject) {
			JSONObject jsonMap = (JSONObject)object;
			Map<Object,Object> map = new HashMap<>();
			Iterator it = jsonMap.entrySet().iterator();
			while (it.hasNext()) {
				Map.Entry pair = (Map.Entry)it.next();
				map.put(pair.getKey(), this.toUniformObjectFromObject(pair.getValue()));
			}
			return new JUniformObject(map);
		
		} else if (object instanceof JSONArray) {
			JSONArray jsonArray = (JSONArray)object;
			ArrayList<Object> array = new ArrayList<>();
			@SuppressWarnings("unchecked")
			Iterator<Object> it = jsonArray.iterator();
			while(it.hasNext()) {
				array.add(this.toUniformObjectFromObject(it.next()));
			}
			return new JUniformObject(array);
		} else {
			return new JUniformObject(object);
		}
	}
	
	@Override
	public Object fromUniformObject(JUniformObject object) {
		return this._toJSON(object);
	}
	
	@Override
	public String fromUniformObjectToString(JUniformObject object) {
		return JSONValue.toJSONString(this._toJSON(object));
	}
	
	@Override
	public byte[] fromUniformObjectToByteArray(JUniformObject object) {
		return this.fromUniformObjectToString(object).getBytes();
	}
	
	// ---------------------------------------------------------------------- //
	// PRIVATE
	// ---------------------------------------------------------------------- //
	
	@SuppressWarnings("unchecked")
	private Object _toJSON(JUniformObject object) {
		if (object == null) {
			return null;
		} else if (object.isMapValue()) {
			JSONObject jsonMap = new JSONObject();
			Iterator<Map.Entry<Object,JUniformObject>> it = object.entrySet().iterator();
			while (it.hasNext()) {
				Map.Entry<Object,JUniformObject> pair = it.next();
				jsonMap.put(pair.getKey(), this._toJSON(pair.getValue()));
			}
			return jsonMap;
		
		} else if (object.isArrayValue()) {
			JSONArray jsonArray = new JSONArray();
			
			Iterator<JUniformObject> it = object.iterator();
			while(it.hasNext()) {
				jsonArray.add(this._toJSON(it.next()));
			}
			return jsonArray;
		} else {
			return object.getValue();
		}
	}
}