pt.ist.processpedia.client.translator.JsonTranslator.java Source code

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Here is the source code for pt.ist.processpedia.client.translator.JsonTranslator.java

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/**
 * Copyright 2011 ESW Software Engineering Group
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 **/

package pt.ist.processpedia.client.translator;

import com.google.gwt.json.client.*;

import pt.ist.processpedia.client.dto.RequestDto;
import pt.ist.processpedia.client.dto.UserDto;
import pt.ist.processpedia.client.exception.RequestAlreadyClaimedException;
import pt.ist.processpedia.client.exception.UserInactiveException;
import pt.ist.processpedia.client.translator.exception.CannotTranslateObjectException;
import pt.ist.processpedia.client.util.ErrorCode;

public class JsonTranslator implements Translator {

    private static final String ID_KEY = "id";
    private static final String ERROR_CODE_KEY = "errorCode";

    public String externalize(Object object) {
        return "";
    }

    public Object parse(String externalizedObject) throws CannotTranslateObjectException {
        JSONValue jsonValue = parseJson(externalizedObject);
        JSONObject jsonObject = jsonValue.isObject();
        if (jsonObject != null) {
            if (jsonObject.containsKey(ID_KEY)) {
                return parseObject(jsonObject);
            } else if (jsonObject.containsKey(ERROR_CODE_KEY)) {
                return parseException(jsonObject);
            } else {
                throw new CannotTranslateObjectException(externalizedObject);
            }
        } else {
            throw new CannotTranslateObjectException(externalizedObject);
        }
    }

    public String getExternalizationContentType() {
        return "application/json";
    }

    private Object parseObject(JSONObject jsonObject) {
        return null;
    }

    public Throwable parseException(JSONObject jsonObject) throws CannotTranslateObjectException {
        String errorCodeString = jsonObject.get(ERROR_CODE_KEY).isString().stringValue();
        ErrorCode errorCode = new ErrorCode(errorCodeString);
        switch (errorCode.getExceptionType()) {
        case REQUEST_ALREADY_CLAIMED:
            return parseRequestAlreadyClaimedExceptionFromJsonObject(jsonObject);
        default:
            throw new CannotTranslateObjectException(jsonObject.toString());
        }
    }

    /**
     * Parses the received exception mapped in a JSON string, hiding the parsing strategy.
     * @param jsonString the exception mapped in a JSON format
     * @return the JSONValue associated to the JSON string
     */
    private static JSONValue parseJson(String jsonString) {
        return JSONParser.parseStrict(jsonString);
    }

    private RequestAlreadyClaimedException parseRequestAlreadyClaimedExceptionFromJsonObject(
            JSONObject jsonObject) {
        RequestDto requestDto = parseRequestDtoFromJsonObject(jsonObject.get("request").isObject());
        return new RequestAlreadyClaimedException(requestDto);
    }

    private UserInactiveException parseUserInactiveExceptionFromJsonObject(JSONObject jsonObject) {
        UserDto userDto = parseUserDtoFromJsonObject(jsonObject.get("user").isObject());
        return new UserInactiveException(userDto);
    }

    private UserDto parseUserDtoFromJsonObject(JSONObject jsonObject) {
        String userId = jsonObject.get("id").isString().stringValue();
        String name = jsonObject.get("name").isString().stringValue();
        return new UserDto(userId, name);
    }

    private RequestDto parseRequestDtoFromJsonObject(JSONObject jsonObject) {
        String requestId = jsonObject.get("id").isString().stringValue();
        String title = jsonObject.get("title").isString().stringValue();
        String description = jsonObject.get("description").isString().stringValue();
        return new RequestDto(requestId, title, description);
    }

}