Java tutorial
/** * This file is part of Graylog. * * Graylog 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. * * Graylog 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 Graylog. If not, see <http://www.gnu.org/licenses/>. */ package org.graylog2.web.resources; import com.google.common.cache.CacheBuilder; import com.google.common.cache.CacheLoader; import com.google.common.cache.LoadingCache; import com.google.common.hash.HashCode; import com.google.common.hash.Hashing; import com.google.common.io.Files; import com.google.common.io.Resources; import org.glassfish.jersey.server.ContainerRequest; import org.graylog2.plugin.Plugin; import org.graylog2.web.IndexHtmlGenerator; import org.graylog2.web.PluginAssets; import javax.activation.MimetypesFileTypeMap; import javax.annotation.Nonnull; import javax.inject.Inject; import javax.inject.Singleton; import javax.ws.rs.GET; import javax.ws.rs.NotFoundException; import javax.ws.rs.Path; import javax.ws.rs.PathParam; import javax.ws.rs.core.CacheControl; import javax.ws.rs.core.Context; import javax.ws.rs.core.EntityTag; import javax.ws.rs.core.HttpHeaders; import javax.ws.rs.core.MediaType; import javax.ws.rs.core.Request; import javax.ws.rs.core.Response; import javax.ws.rs.core.UriBuilder; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.net.URI; import java.net.URISyntaxException; import java.net.URL; import java.nio.file.FileSystem; import java.nio.file.FileSystemAlreadyExistsException; import java.nio.file.FileSystemNotFoundException; import java.nio.file.FileSystems; import java.nio.file.attribute.FileTime; import java.util.Collections; import java.util.Date; import java.util.Optional; import java.util.Set; import java.util.concurrent.TimeUnit; import static com.google.common.base.MoreObjects.firstNonNull; import static java.util.Objects.requireNonNull; @Singleton @Path("") public class WebInterfaceAssetsResource { private final MimetypesFileTypeMap mimeTypes; private final IndexHtmlGenerator indexHtmlGenerator; private final Set<Plugin> plugins; private final LoadingCache<URI, FileSystem> fileSystemCache; @Inject public WebInterfaceAssetsResource(IndexHtmlGenerator indexHtmlGenerator, Set<Plugin> plugins, MimetypesFileTypeMap mimeTypes) { this.indexHtmlGenerator = indexHtmlGenerator; this.plugins = plugins; this.mimeTypes = requireNonNull(mimeTypes); fileSystemCache = CacheBuilder.newBuilder().maximumSize(1024).build(new CacheLoader<URI, FileSystem>() { @Override public FileSystem load(@Nonnull URI key) throws Exception { try { return FileSystems.getFileSystem(key); } catch (FileSystemNotFoundException e) { try { return FileSystems.newFileSystem(key, Collections.emptyMap()); } catch (FileSystemAlreadyExistsException f) { return FileSystems.getFileSystem(key); } } } }); } @Path("plugin/{plugin}/{filename}") @GET public Response get(@Context Request request, @PathParam("plugin") String pluginName, @PathParam("filename") String filename) { final Optional<Plugin> plugin = getPluginForName(pluginName); if (!plugin.isPresent()) { throw new NotFoundException("Couldn't find plugin " + pluginName); } try { final URL resourceUrl = getResourceUri(true, filename, plugin.get().metadata().getClass()); return getResponse(request, filename, resourceUrl, true); } catch (URISyntaxException | IOException e) { throw new NotFoundException("Couldn't find " + filename + " in plugin " + pluginName, e); } } private Optional<Plugin> getPluginForName(String pluginName) { return this.plugins.stream().filter(plugin -> plugin.metadata().getUniqueId().equals(pluginName)) .findFirst(); } @Path("{filename: .*}") @GET public Response get(@Context Request request, @PathParam("filename") String filename) { if (filename == null || filename.isEmpty() || filename.equals("/") || filename.equals("index.html")) { return getDefaultResponse(); } try { final URL resourceUrl = getResourceUri(false, filename, this.getClass()); return getResponse(request, filename, resourceUrl, false); } catch (IOException | URISyntaxException e) { return getDefaultResponse(); } } @GET public Response getIndex(@Context ContainerRequest request) { final URI originalLocation = request.getRequestUri(); if (originalLocation.getPath().endsWith("/")) { return get(request, originalLocation.getPath()); } final URI redirect = UriBuilder.fromPath(originalLocation.getPath() + "/").build(); return Response.temporaryRedirect(redirect).build(); } private Response getResponse(Request request, String filename, URL resourceUrl, boolean fromPlugin) throws IOException, URISyntaxException { final Date lastModified; final InputStream stream; final HashCode hashCode; switch (resourceUrl.getProtocol()) { case "file": { final File file = new File(resourceUrl.toURI()); lastModified = new Date(file.lastModified()); stream = new FileInputStream(file); hashCode = Files.hash(file, Hashing.sha256()); break; } case "jar": { final URI uri = resourceUrl.toURI(); final FileSystem fileSystem = fileSystemCache.getUnchecked(uri); final java.nio.file.Path path = fileSystem.getPath(pluginPrefixFilename(fromPlugin, filename)); final FileTime lastModifiedTime = java.nio.file.Files.getLastModifiedTime(path); lastModified = new Date(lastModifiedTime.toMillis()); stream = resourceUrl.openStream(); hashCode = Resources.asByteSource(resourceUrl).hash(Hashing.sha256()); break; } default: throw new IllegalArgumentException("Not a jar or file"); } final EntityTag entityTag = new EntityTag(hashCode.toString()); final Response.ResponseBuilder response = request.evaluatePreconditions(lastModified, entityTag); if (response != null) { return response.build(); } final String contentType = firstNonNull(mimeTypes.getContentType(filename), MediaType.APPLICATION_OCTET_STREAM); final CacheControl cacheControl = new CacheControl(); cacheControl.setMaxAge((int) TimeUnit.DAYS.toSeconds(365)); cacheControl.setNoCache(false); cacheControl.setPrivate(false); return Response.ok(stream).header(HttpHeaders.CONTENT_TYPE, contentType).tag(entityTag) .cacheControl(cacheControl).lastModified(lastModified).build(); } private URL getResourceUri(boolean fromPlugin, String filename, Class<?> aClass) throws URISyntaxException, FileNotFoundException { final URL resourceUrl = aClass.getResource(pluginPrefixFilename(fromPlugin, filename)); if (resourceUrl == null) { throw new FileNotFoundException("Resource file " + filename + " not found."); } return resourceUrl; } @Nonnull private String pluginPrefixFilename(boolean fromPlugin, String filename) { if (fromPlugin) { return "/" + filename; } else { return "/" + PluginAssets.pathPrefix + "/" + filename; } } private Response getDefaultResponse() { return Response.ok(this.indexHtmlGenerator.get()).header(HttpHeaders.CONTENT_TYPE, MediaType.TEXT_HTML) .header("X-UA-Compatible", "IE=edge").build(); } }