src/main/java/de/uapcore/lightpit/modules/ErrorModule.java

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2018 Mike Becker. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */
package de.uapcore.lightpit.modules;

import de.uapcore.lightpit.*;

import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.Optional;

/**
 * Entry point for the application.
 */
@LightPITModule(
        bundleBaseName = "localization.error",
        modulePath = "error",
        systemModule = true
)
@WebServlet(
        name = "ErrorModule",
        urlPatterns = "/error/*"
)
public final class ErrorModule extends AbstractLightPITServlet {

    public static final String REQ_ATTR_RETURN_LINK = "returnLink";

    @RequestMapping(requestPath = "generic", method = HttpMethod.GET)
    public ResponseType onError(HttpServletRequest req, HttpServletResponse resp) {
        Optional.ofNullable(req.getHeader("Referer")).ifPresent(
                referer -> req.setAttribute(REQ_ATTR_RETURN_LINK, referer)
        );

        setStylesheet(req, "error");
        setContentPage(req, "error");

        return ResponseType.HTML;
    }
}