com.github.mrstampy.gameboot.messages.GameBootMessageConverter.java Source code

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Here is the source code for com.github.mrstampy.gameboot.messages.GameBootMessageConverter.java

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/*
 *              ______                        ____              __ 
 *             / ____/___ _____ ___  ___     / __ )____  ____  / /_
 *            / / __/ __ `/ __ `__ \/ _ \   / __  / __ \/ __ \/ __/
 *           / /_/ / /_/ / / / / / /  __/  / /_/ / /_/ / /_/ / /_  
 *           \____/\__,_/_/ /_/ /_/\___/  /_____/\____/\____/\__/  
 *                                                 
 *                                 .-'\
 *                              .-'  `/\
 *                           .-'      `/\
 *                           \         `/\
 *                            \         `/\
 *                             \    _-   `/\       _.--.
 *                              \    _-   `/`-..--\     )
 *                               \    _-   `,','  /    ,')
 *                                `-_   -   ` -- ~   ,','
 *                                 `-              ,','
 *                                  \,--.    ____==-~
 *                                   \   \_-~\
 *                                    `_-~_.-'
 *                                     \-~
 * 
 *                       http://mrstampy.github.io/gameboot/
 *
 * Copyright (C) 2015, 2016 Burton Alexander
 * 
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option) any later
 * version.
 * 
 * This program 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
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * 
 */
package com.github.mrstampy.gameboot.messages;

import static org.apache.commons.lang3.StringUtils.isEmpty;

import java.io.IOException;
import java.lang.invoke.MethodHandles;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.github.mrstampy.gameboot.exception.GameBootException;
import com.github.mrstampy.gameboot.messages.context.ResponseContext;
import com.github.mrstampy.gameboot.messages.context.ResponseContextCodes;
import com.github.mrstampy.gameboot.messages.context.ResponseContextLookup;
import com.github.mrstampy.gameboot.messages.finder.MessageClassFinder;

/**
 * The Class GameBootMessageConverter.
 */
@Component
public class GameBootMessageConverter implements ResponseContextCodes {
    private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());

    private static final String TYPE_NODE_NAME = "type";

    @Autowired
    private ObjectMapper mapper;

    @Autowired
    private MessageClassFinder finder;

    @Autowired
    private ResponseContextLookup lookup;

    /**
     * From json.
     *
     * @param <AGBM>
     *          the generic type
     * @param message
     *          the message
     * @return the agbm
     * @throws IOException
     *           Signals that an I/O exception has occurred.
     * @throws GameBootException
     *           the game boot exception
     */
    public <AGBM extends AbstractGameBootMessage> AGBM fromJson(String message)
            throws IOException, GameBootException {
        if (isEmpty(message))
            fail(getResponseContext(NO_MESSAGE), "No message");

        JsonNode node = mapper.readTree(message);

        return fromJson(message.getBytes(), node);
    }

    /**
     * From json.
     *
     * @param <AGBM>
     *          the generic type
     * @param message
     *          the message
     * @return the agbm
     * @throws IOException
     *           Signals that an I/O exception has occurred.
     * @throws GameBootException
     *           the game boot exception
     */
    public <AGBM extends AbstractGameBootMessage> AGBM fromJson(byte[] message)
            throws IOException, GameBootException {
        if (message == null || message.length == 0)
            fail(getResponseContext(NO_MESSAGE), "No message");

        JsonNode node = mapper.readTree(message);

        return fromJson(message, node);
    }

    @SuppressWarnings("unchecked")
    private <AGBM extends AbstractGameBootMessage> AGBM fromJson(byte[] message, JsonNode node)
            throws GameBootException, IOException, JsonParseException, JsonMappingException {
        JsonNode typeNode = node.get(TYPE_NODE_NAME);

        if (typeNode == null)
            fail(getResponseContext(NO_TYPE), "No type specified");

        String type = typeNode.asText();

        if (isEmpty(type))
            fail(getResponseContext(NO_TYPE), "No type specified");

        Class<?> clz = finder.findClass(type);

        if (clz == null) {
            log.error("Unknown message type {} for message {}", type, message);
            fail(getResponseContext(UNKNOWN_MESSAGE), "Unrecognized message");
        }

        return (AGBM) mapper.readValue(message, clz);
    }

    /**
     * To json.
     *
     * @param <AGBM>
     *          the generic type
     * @param msg
     *          the msg
     * @return the string
     * @throws JsonProcessingException
     *           the json processing exception
     * @throws GameBootException
     *           the game boot exception
     */
    public <AGBM extends AbstractGameBootMessage> String toJson(AGBM msg)
            throws JsonProcessingException, GameBootException {
        if (msg == null)
            fail(getResponseContext(NO_MESSAGE), "No message");

        return mapper.writeValueAsString(msg);
    }

    /**
     * To json array.
     *
     * @param <AGBM>
     *          the generic type
     * @param msg
     *          the msg
     * @return the byte[]
     * @throws JsonProcessingException
     *           the json processing exception
     * @throws GameBootException
     *           the game boot exception
     */
    public <AGBM extends AbstractGameBootMessage> byte[] toJsonArray(AGBM msg)
            throws JsonProcessingException, GameBootException {
        if (msg == null)
            fail(getResponseContext(NO_MESSAGE), "No message");

        return mapper.writeValueAsBytes(msg);
    }

    private ResponseContext getResponseContext(Integer code, Object... parameters) {
        return lookup.lookup(code, parameters);
    }

    private void fail(ResponseContext rc, String msg, Object... payload) throws GameBootException {
        throw new GameBootException(msg, rc, payload);
    }
}