Java tutorial
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We also recommend that a * file or class name and description of purpose be included on the * same "printed page" as the copyright notice for easier * identification within third-party archives. * * Copyright 2014 Edgar Espina * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.jooby.livereload; import com.google.common.base.CaseFormat; import com.google.common.collect.ImmutableSet; import com.google.inject.Binder; import com.typesafe.config.Config; import org.jooby.Env; import org.jooby.Jooby.Module; import org.jooby.MediaType; import org.jooby.Request; import org.jooby.Route; import org.jooby.Router; import org.jooby.WebSocket; import org.jooby.filewatcher.FileWatcher; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.File; import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.Paths; import java.util.ArrayList; import java.util.Arrays; import java.util.LinkedHashMap; import java.util.List; import java.util.Map; import java.util.Queue; import java.util.Set; import java.util.concurrent.ConcurrentLinkedQueue; import java.util.concurrent.atomic.AtomicBoolean; import java.util.function.Predicate; /** * <h1>liveReload</h1> * <p> * <a href="http://livereload.com">LiveReload</a> monitors changes in the file system. As soon as * you save a file, it is preprocessed as * needed, and the browser is refreshed. * </p> * <p> * Even cooler, when you change a CSS file or an image, the browser is updated instantly without * reloading the page. * </p> * * <h2>usage</h2> * <pre>{@code * { * use(new Jackson()); * * use(new LiveReload()); * } * }</pre> * * <p> * This module is available as long you run in development: <code>application.env=dev</code>. * </p> * * <h2>configuration</h2> * * <h3>browser extension</h3> * <p> * Install the <a href="http://livereload.com/extensions/">LiveReload browser extension.</a> * </p> * * <h3>livereload.js</h3> * <p> * Add the <code>livereload.js</code> to your web page. * </p> * * <p> * You can do this manually: * </p> * * <pre>{@code * <script src="/livereload.js"></script> * }</pre> * * <p> * Or use the <code>liveReload</code> local variable with your preferred template engine. Here is an * example using <code>Handlebars</code>: * </p> * * <pre> * {{liveReload}} * </pre> * * <h3>json module</h3> * <p> * The <a href= * "http://feedback.livereload.com/knowledgebase/articles/86174-livereload-protocol">LiveReload * Protocol</a> run on top of a <code>WebSocket</code> and uses <code>JSON</code> as protocol * format. That's is why we also need to install a <code>JSON module</code>, like <a * href="http://jooby.org/doc/jackson">Jackson</a>. * </p> * * <h2>watcher</h2> * <p> * It automatically reload static resources from <code>public</code>, <code>target</code> (Maven * projects) or <code>build</code> folders (Gradle projects). * </p> * * <p> * Every time a change is detected the websocket send a <code>reload command</code>. * </p> * * <p> * That's all folks!! * </p> * * @author edgar * @since 1.1.0 */ public class LiveReload implements Module { public static final String V7 = "http://livereload.com/protocols/official-7"; /** The logging system. */ private final Logger log = LoggerFactory.getLogger(getClass()); private static final Set<String> CSS = ImmutableSet.of(".css", ".scss", ".sass", ".less"); private Predicate<Path> css = path -> CSS.stream().filter(ext -> path.toString().endsWith(ext)).findFirst() .isPresent(); private List<Object[]> paths = new ArrayList<>(); /** * Add the given path to the watcher. * * @param path Path to watch. * @param includes Glob pattern of matching files. * @return This module. */ public LiveReload register(final Path path, final String... includes) { if (Files.exists(path)) { paths.add(new Object[] { path, Arrays.asList(includes) }); } return this; } /** * Test if a path is a css like file (less, sass, etc.). * * @param predicate CSS predicate. * @return This module. */ public LiveReload liveCss(final Predicate<Path> predicate) { this.css = predicate; return this; } @SuppressWarnings("unchecked") @Override public void configure(final Env env, final Config conf, final Binder binder) throws Throwable { boolean enabled = conf.hasPath("livereload.enabled") ? conf.getBoolean("livereload.enabled") : "dev".equals(env.name()); if (enabled) { Router router = env.router(); /** * Livereload client: */ String livereloadjs = "/" + LiveReload.class.getPackage().getName().replace(".", "/") + "/livereload.js"; router.assets("/livereload.js", livereloadjs); /** {{liveReload}} local variable */ router.use("*", (req, rsp) -> req.set("liveReload", template(req))).name("livereload"); String serverName = CaseFormat.LOWER_CAMEL.to(CaseFormat.UPPER_CAMEL, conf.getString("application.name")); Queue<WebSocket> broadcast = new ConcurrentLinkedQueue<>(); AtomicBoolean first = new AtomicBoolean(true); /** * Websocket: */ router.ws("/livereload", ws -> { // add to broadcast broadcast.add(ws); ws.onMessage(msg -> { Map<String, Object> cmd = msg.to(Map.class); log.debug("command: {}", cmd); Map<String, Object> rsp = handshake(cmd, serverName, V7); if (rsp != null) { log.debug("sending: {}", rsp); ws.send(rsp); } else { log.trace("ignoring command: {}", cmd); // resync app state after a jooby:run restart if (first.compareAndSet(true, false)) { int counter = Integer.parseInt(System.getProperty("joobyRun.counter", "0")); if (counter > 0) { ws.send(reload("/", true)); } } } }); // remove from broadcast ws.onClose(reason -> broadcast.remove(ws)); }).consumes(MediaType.json).produces(MediaType.json); if (paths.isEmpty()) { Path basedir = Paths.get(System.getProperty("user.dir")); Path assetsDir; if (conf.hasPath("assets.outputDir")) { assetsDir = Paths.get(conf.getString("assets.outputDir")); } else { assetsDir = basedir.resolve("public"); } register(basedir.resolve("public"), "**/*.html", "**/*.ftl", "**/*.hbs", "**/*.jade"); register(assetsDir, "**/*.css", "**/*.scss", "**/*.sass", "**/*.less", "**/*.js", "**/*.coffee", "**/*.ts"); register(basedir.resolve("target"), "**/*.class", "**/*.conf", "**/*.properties"); register(basedir.resolve("build"), "**/*.class", "**/*.conf", "**/*.properties"); } if (paths.size() > 0) { FileWatcher watcher = new FileWatcher(); paths.forEach(it -> watcher.register((Path) it[0], (kind, path) -> { Path relative = relative(paths, path.toAbsolutePath()); log.debug("file changed {}: {}", relative, File.separator); Map<String, Object> reload = reload( Route.normalize("/" + relative.toString().replace(File.separator, "/")), css.test(relative)); for (WebSocket ws : broadcast) { try { log.debug("sending: {}", reload); ws.send(reload); } catch (Exception x) { log.debug("execution of {} resulted in exception", reload, x); } } }, options -> ((List<String>) it[1]).forEach(options::includes))); watcher.configure(env, conf, binder); } else { log.warn("File watcher is off"); } } } private String template(Request req) { String contextPath = req.contextPath(); return "<script>" + "window.LiveReloadOptions = {" + "host: '" + req.hostname() + "'," + "port: '" + req.port() + contextPath + "'" + "};" + "</script>\n" + "<script src=\"" + contextPath + "/livereload.js\"></script>"; } private boolean isHello(final Map<String, Object> message) { return "hello".equals(message.get("command")); } @SuppressWarnings("unchecked") private Map<String, Object> handshake(final Map<String, Object> client, final String serverName, final String version) { if (isHello(client)) { List<String> protocols = (List<String>) client.get("protocols"); return protocols.stream().filter(protocol -> version.equalsIgnoreCase(protocol)).map(protocol -> { Map<String, Object> server = new LinkedHashMap<>(); server.put("command", "hello"); server.put("protocols", new String[] { protocol }); server.put("serverName", serverName); return server; }).findFirst().orElse(null); } return null; } private Path relative(final List<Object[]> paths, final Path path) { for (Object[] meta : paths) { Path root = ((Path) meta[0]).toAbsolutePath(); Path relative = root.relativize(path); if (Files.exists(root.resolve(relative))) { return relative; } } return path; } private Map<String, Object> reload(final String path, final boolean liveCss) { Map<String, Object> cmd = new LinkedHashMap<>(); cmd.put("command", "reload"); cmd.put("path", path); cmd.put("liveCSS", liveCss); return cmd; } }