Java tutorial
/* * Copyright 2012-2018 the original author or authors. * * 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.springframework.boot.web.embedded.undertow; import java.io.Closeable; import java.lang.reflect.Field; import java.net.BindException; import java.net.InetSocketAddress; import java.net.SocketAddress; import java.util.ArrayList; import java.util.List; import io.undertow.Undertow; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.xnio.channels.BoundChannel; import org.springframework.boot.web.server.PortInUseException; import org.springframework.boot.web.server.WebServer; import org.springframework.boot.web.server.WebServerException; import org.springframework.util.ReflectionUtils; import org.springframework.util.StringUtils; /** * {@link WebServer} that can be used to control an Undertow web server. Usually this * class should be created using the {@link UndertowReactiveWebServerFactory} and not * directly. * * @author Ivan Sopov * @author Andy Wilkinson * @author Edd Melndez * @author Christoph Dreis * @author Brian Clozel * @since 2.0.0 */ public class UndertowWebServer implements WebServer { private static final Log logger = LogFactory.getLog(UndertowServletWebServer.class); private final Object monitor = new Object(); private final Undertow.Builder builder; private final boolean autoStart; private final Closeable closeable; private Undertow undertow; private volatile boolean started = false; /** * Create a new {@link UndertowWebServer} instance. * @param builder the builder * @param autoStart if the server should be started */ public UndertowWebServer(Undertow.Builder builder, boolean autoStart) { this(builder, autoStart, null); } /** * Create a new {@link UndertowWebServer} instance. * @param builder the builder * @param autoStart if the server should be started * @param closeable called when the server is stopped * @since 2.0.4 */ public UndertowWebServer(Undertow.Builder builder, boolean autoStart, Closeable closeable) { this.builder = builder; this.autoStart = autoStart; this.closeable = closeable; } @Override public void start() throws WebServerException { synchronized (this.monitor) { if (this.started) { return; } try { if (!this.autoStart) { return; } if (this.undertow == null) { this.undertow = this.builder.build(); } this.undertow.start(); this.started = true; UndertowWebServer.logger.info("Undertow started on port(s) " + getPortsDescription()); } catch (Exception ex) { try { if (findBindException(ex) != null) { List<UndertowWebServer.Port> failedPorts = getConfiguredPorts(); List<UndertowWebServer.Port> actualPorts = getActualPorts(); failedPorts.removeAll(actualPorts); if (failedPorts.size() == 1) { throw new PortInUseException(failedPorts.iterator().next().getNumber()); } } throw new WebServerException("Unable to start embedded Undertow", ex); } finally { stopSilently(); } } } } private void stopSilently() { try { if (this.undertow != null) { this.undertow.stop(); this.closeable.close(); } } catch (Exception ex) { // Ignore } } private BindException findBindException(Exception ex) { Throwable candidate = ex; while (candidate != null) { if (candidate instanceof BindException) { return (BindException) candidate; } candidate = candidate.getCause(); } return null; } private String getPortsDescription() { List<UndertowWebServer.Port> ports = getActualPorts(); if (!ports.isEmpty()) { return StringUtils.collectionToDelimitedString(ports, " "); } return "unknown"; } private List<UndertowWebServer.Port> getActualPorts() { List<UndertowWebServer.Port> ports = new ArrayList<>(); try { if (!this.autoStart) { ports.add(new UndertowWebServer.Port(-1, "unknown")); } else { for (BoundChannel channel : extractChannels()) { ports.add(getPortFromChannel(channel)); } } } catch (Exception ex) { // Continue } return ports; } @SuppressWarnings("unchecked") private List<BoundChannel> extractChannels() { Field channelsField = ReflectionUtils.findField(Undertow.class, "channels"); ReflectionUtils.makeAccessible(channelsField); return (List<BoundChannel>) ReflectionUtils.getField(channelsField, this.undertow); } private UndertowWebServer.Port getPortFromChannel(BoundChannel channel) { SocketAddress socketAddress = channel.getLocalAddress(); if (socketAddress instanceof InetSocketAddress) { Field sslField = ReflectionUtils.findField(channel.getClass(), "ssl"); String protocol = (sslField != null) ? "https" : "http"; return new UndertowWebServer.Port(((InetSocketAddress) socketAddress).getPort(), protocol); } return null; } private List<UndertowWebServer.Port> getConfiguredPorts() { List<UndertowWebServer.Port> ports = new ArrayList<>(); for (Object listener : extractListeners()) { try { ports.add(getPortFromListener(listener)); } catch (Exception ex) { // Continue } } return ports; } @SuppressWarnings("unchecked") private List<Object> extractListeners() { Field listenersField = ReflectionUtils.findField(Undertow.class, "listeners"); ReflectionUtils.makeAccessible(listenersField); return (List<Object>) ReflectionUtils.getField(listenersField, this.undertow); } private UndertowWebServer.Port getPortFromListener(Object listener) { Field typeField = ReflectionUtils.findField(listener.getClass(), "type"); ReflectionUtils.makeAccessible(typeField); String protocol = ReflectionUtils.getField(typeField, listener).toString(); Field portField = ReflectionUtils.findField(listener.getClass(), "port"); ReflectionUtils.makeAccessible(portField); int port = (Integer) ReflectionUtils.getField(portField, listener); return new UndertowWebServer.Port(port, protocol); } @Override public void stop() throws WebServerException { synchronized (this.monitor) { if (!this.started) { return; } this.started = false; try { this.undertow.stop(); if (this.closeable != null) { this.closeable.close(); } } catch (Exception ex) { throw new WebServerException("Unable to stop undertow", ex); } } } @Override public int getPort() { List<UndertowWebServer.Port> ports = getActualPorts(); if (ports.isEmpty()) { return 0; } return ports.get(0).getNumber(); } /** * An active Undertow port. */ private static final class Port { private final int number; private final String protocol; private Port(int number, String protocol) { this.number = number; this.protocol = protocol; } public int getNumber() { return this.number; } @Override public boolean equals(Object obj) { if (this == obj) { return true; } if (obj == null) { return false; } if (getClass() != obj.getClass()) { return false; } UndertowWebServer.Port other = (UndertowWebServer.Port) obj; if (this.number != other.number) { return false; } return true; } @Override public int hashCode() { return this.number; } @Override public String toString() { return this.number + " (" + this.protocol + ")"; } } }