org.ownchan.server.app.config.WebMvcConfig.java Source code

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Here is the source code for org.ownchan.server.app.config.WebMvcConfig.java

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/*******************************************************************************
 * @author Stefan Gndhr <stefan@guendhoer.com>
 *
 * @copyright Copyright (c) 2017, Stefan Gndhr <stefan@guendhoer.com>
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License, version 3,
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *******************************************************************************/
package org.ownchan.server.app.config;

import java.util.concurrent.TimeUnit;
import java.util.stream.Stream;

import org.apache.commons.lang3.StringUtils;
import org.ownchan.server.app.ScanBaseMarker;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.CacheControl;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

@Configuration
public class WebMvcConfig extends WebMvcConfigurerAdapter {

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        String implementationVersion = ScanBaseMarker.class.getPackage().getImplementationVersion();

        String pathVersion;
        CacheControl cacheControl;
        if (StringUtils.isNotBlank(implementationVersion)) {
            /*
             * As we use versioning for the GUI URL paths, we can cache "forever".
             * Browsers will re-validate when the resource's URL changes with every new version of the application.
             */
            cacheControl = CacheControl.maxAge(365, TimeUnit.DAYS);
            pathVersion = implementationVersion;
        } else {
            /*
             * If the application is started directly in the DEV IDE,
             * we don't cache and allow all versions in the path.
             */
            cacheControl = CacheControl.noStore();
            pathVersion = "{version:[a-zA-Z0-9\\.\\-]+}";
        }

        addStaticResourceHandlers(registry, cacheControl, "/static/" + pathVersion + "/**");
    }

    private void addStaticResourceHandlers(ResourceHandlerRegistry registry, CacheControl cacheControl,
            String... patterns) {
        Stream.of(patterns).filter(pattern -> !registry.hasMappingForPattern(pattern))
                .map(registry::addResourceHandler).forEach(handler -> handler
                        .addResourceLocations("classpath:/webstatic/").setCacheControl(cacheControl));
    }

}