src/main/java/de/uapcore/lightpit/Functions.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;

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

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import java.util.Optional;

/**
 * Contains common static functions.
 */
public final class Functions {

    private static final Logger LOG = LoggerFactory.getLogger(Functions.class);

    public static Optional<String[]> availableLanguages(ServletContext ctx) {
        return Optional.ofNullable(ctx.getInitParameter(Constants.CTX_ATTR_LANGUAGES)).map((x) -> x.split("\\s*,\\s*"));
    }

    public static String enforceExt(String filename, String ext) {
        return filename.endsWith(ext) ? filename : filename + ext;
    }

    public static String jspPath(String filename) {
        return enforceExt(Constants.JSP_PATH_PREFIX + filename, ".jsp");
    }

    public static String dynFragmentPath(String filename) {
        return enforceExt(Constants.DYN_FRAGMENT_PATH_PREFIX + filename, ".jsp");
    }

    public static String fqn(String base, String name) {
        return base + "." + name;
    }

    public static String fqn(Class<?> clazz, String name) {
        return fqn(clazz.getName(), name);
    }

    public static String baseHref(HttpServletRequest req) {
        return String.format("%s://%s:%d%s/",
                req.getScheme(),
                req.getServerName(),
                req.getServerPort(),
                req.getContextPath());
    }

    public static String fullPath(HttpServletRequest req) {
        return req.getServletPath() + Optional.ofNullable(req.getPathInfo()).orElse("");
    }

    /**
     * Returns the module path of the given LightPIT Servlet module.
     * <p>
     * If you specify a malformed LightPIT servlet, which does not have a module
     * annotation, the path to the <code>/error/404.html</code> page is returned.
     *
     * @param clazz the servlet class
     * @return the module path
     */
    public static String modulePathOf(Class<? extends AbstractLightPITServlet> clazz) {
        Optional<LightPITModule> moduleInfo = Optional.ofNullable(clazz.getAnnotation(LightPITModule.class));
        if (moduleInfo.isPresent()) {
            return moduleInfo.get().modulePath();
        } else {
            LOG.warn(
                    "{} is a LightPIT Servlet but is missing the module annotation.",
                    clazz.getName()
            );
            return "/error/404.html";
        }
    }

    /**
     * This class is not instantiatable.
     */
    private Functions() {
    }
}