com.balajeetm.mystique.core.TransformFunction.java Source code

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Here is the source code for com.balajeetm.mystique.core.TransformFunction.java

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/*
 * Copyright (c) Balajee TM 2016.
 * All rights reserved.
 * License -  @see <a href="http://www.apache.org/licenses/LICENSE-2.0"></a>
 */

/*
 * Created on 25 Aug, 2016 by balajeetm
 * http://www.balajeetm.com
 */
package com.balajeetm.mystique.core;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.balajeetm.mystique.core.util.MystiqueConstants;
import com.balajeetm.mystique.util.gson.lever.JsonLever;
import com.google.gson.JsonElement;
import com.google.gson.JsonNull;
import com.google.gson.JsonObject;
import com.google.gson.JsonPrimitive;

/**
 * The Class TransformFunction.
 *
 * @author balajeetm
 */
public class TransformFunction implements MystiqueFunction {

    /** The json lever. */
    private JsonLever jsonLever;

    /** Instantiates a new transform function. */
    private TransformFunction() {
        jsonLever = JsonLever.getInstance();
    }

    /**
     * Gets the single instance of TransformFunction.
     *
     * @return single instance of TransformFunction
     */
    public static TransformFunction getInstance() {
        return Creator.INSTANCE;
    }

    // Efficient Thread safe Lazy Initialization
    // works only if the singleton constructor is non parameterized
    /** The Class Creator. */
    private static class Creator {

        /** The instance. */
        private static TransformFunction INSTANCE = new TransformFunction();
    }

    /** The logger. */
    protected Logger logger = LoggerFactory.getLogger(this.getClass().getName());

    /* (non-Javadoc)
     * @see com.futuresight.util.mystique.MystFunction#execute(com.google.gson.JsonElement, com.google.gson.JsonObject)
     */
    @Override
    public JsonElement execute(JsonElement source, JsonObject turn) {
        JsonElement result = JsonNull.INSTANCE;
        if (jsonLever.isNotNull(source)) {
            turn = jsonLever.asJsonObject(turn, new JsonObject());
            String formatIn = jsonLever.asString(turn.get(MystiqueConstants.INFORMAT), MystiqueConstants.DEFAULT);
            Date inputDate = null;
            try {
                switch (formatIn) {
                case MystiqueConstants.DEFAULT: {
                    Long time = jsonLever.asLong(source);
                    time = time == null ? Long.valueOf(jsonLever.asString(source)) : time;
                    inputDate = new Date(time);
                    break;
                }

                case MystiqueConstants.LONG: {
                    Long time = jsonLever.asLong(source);
                    inputDate = new Date(time);
                    break;
                }

                case MystiqueConstants.STRING: {
                    String time = jsonLever.asString(source);
                    inputDate = new Date(Long.valueOf(time));
                    break;
                }

                default:
                    inputDate = new SimpleDateFormat(formatIn).parse(jsonLever.asString(source));
                    break;
                }
            } catch (ParseException e) {
                logger.warn(String.format("Error while parsing input date %s for format %s : %s", source, formatIn,
                        e.getMessage()), e);
            }
            String outFormat = jsonLever.asString(turn.get(MystiqueConstants.OUTFORMAT), MystiqueConstants.LONG);
            result = getFormattedDate(inputDate, outFormat);
        }
        return result;
    }

    /**
     * Gets the formatted date.
     *
     * @param date the date
     * @param dateFormat the date format
     * @return the formatted date
     */
    public JsonElement getFormattedDate(Date date, String dateFormat) {
        JsonElement output;
        switch (dateFormat) {
        case MystiqueConstants.LONG:
            output = new JsonPrimitive(date.getTime());
            break;

        case MystiqueConstants.STRING:
            output = new JsonPrimitive(String.valueOf(date.getTime()));
            break;

        default:
            output = new JsonPrimitive(new SimpleDateFormat(dateFormat).format(date));
            break;
        }
        return output;
    }
}