de.liedtke.presentation.WebCommand.java Source code

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Here is the source code for de.liedtke.presentation.WebCommand.java

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/*
 * ljal - Java App Engine library
 * 
 * Copyright (C) 2012 Steve Liedtke <sliedtke57@gmail.com>
 * 
 * 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 can find a copy of the GNU General Public License on http://www.gnu.org/licenses/gpl.html.
 * 
 * Contributors:
 *     Steve Liedtke <sliedtke57@gmail.com>
 */
package de.liedtke.presentation;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Logger;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.json.JSONObject;
import org.mortbay.log.Log;

import de.liedtke.business.api.CloseService;
import de.liedtke.format.FormatFactory;
import de.liedtke.format.Formatter;
import de.liedtke.validation.ValidationException;

public abstract class WebCommand {

    /**
     * static attribute used for logging.
     */
    private static final Logger logger = Logger.getLogger(WebCommand.class.getName());

    protected HttpServletRequest req;

    protected HttpServletResponse resp;

    protected JSONObject json;

    protected Result result;

    protected Formatter formatter;

    protected ErrorMessages errorMessages;

    private List<CloseService> services = new ArrayList<CloseService>();

    public <T extends ErrorMessages> void init(final HttpServletRequest req, final HttpServletResponse resp,
            final Class<T> errorMessageClass) {
        if (req == null || resp == null) {
            Log.warn(this.getClass().getSimpleName() + ": Response and/or Request are null!");
            throw new NullPointerException();
        }
        final String kind = req.getParameter("format");
        try {
            this.errorMessages = ErrorMessageFactory.getSingleton(errorMessageClass);
        } catch (InitializationException e) {
            this.errorMessages = null;
            logger.warning("Initialization of errormessages failed!");
        }
        this.result = new Result(kind, errorMessages);
        this.req = req;
        this.resp = resp;
        this.formatter = FormatFactory.getFormatter(kind);
    }

    protected void handleError(ValidationException ve) {
        this.handleError(ve.getErrorCode());
    }

    protected void handleError(final int errorCode) {
        resp.setStatus(HttpServletResponse.SC_BAD_REQUEST);
        final String error;
        if (this.errorMessages == null) {
            error = "";
        } else {
            error = this.errorMessages.getMessage(errorCode);
        }
        result.addError(error, errorCode);
    }

    protected void handleSuccess(final String message, final String result) {
        resp.setStatus(HttpServletResponse.SC_OK);
        this.result.addSuccess(message);
        if (result != null)
            this.result.addResult(result);
    }

    public void process() throws ServletException, IOException {
        resp.setHeader("Content-Type", "text/javascript; charset=UTF-8");
        resp.setCharacterEncoding("UTF-8");
        final String res = result.toString();
        resp.getWriter().append(res);
        logger.info(res);
        for (final CloseService service : services) {
            service.close();
        }
    }

    protected void registerService(final CloseService... paramServices) {
        for (final CloseService service : services) {
            services.add(service);
        }
    }
}