org.springframework.boot.context.embedded.undertow.UndertowEmbeddedServletContainer.java Source code

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/*
 * Copyright 2012-2015 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.context.embedded.undertow;

import java.lang.reflect.Field;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.ServletException;

import io.undertow.Handlers;
import io.undertow.Undertow;
import io.undertow.Undertow.Builder;
import io.undertow.attribute.RequestHeaderAttribute;
import io.undertow.predicate.Predicate;
import io.undertow.predicate.Predicates;
import io.undertow.server.HttpHandler;
import io.undertow.server.HttpServerExchange;
import io.undertow.server.handlers.encoding.ContentEncodingRepository;
import io.undertow.server.handlers.encoding.EncodingHandler;
import io.undertow.server.handlers.encoding.GzipEncodingProvider;
import io.undertow.servlet.api.DeploymentManager;
import io.undertow.util.HttpString;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.xnio.channels.BoundChannel;

import org.springframework.boot.context.embedded.Compression;
import org.springframework.boot.context.embedded.EmbeddedServletContainer;
import org.springframework.boot.context.embedded.EmbeddedServletContainerException;
import org.springframework.http.HttpHeaders;
import org.springframework.util.MimeType;
import org.springframework.util.MimeTypeUtils;
import org.springframework.util.ReflectionUtils;
import org.springframework.util.StringUtils;

/**
 * {@link EmbeddedServletContainer} that can be used to control an embedded Undertow
 * server. Typically this class should be created using
 * {@link UndertowEmbeddedServletContainerFactory} and not directly.
 *
 * @author Ivan Sopov
 * @author Andy Wilkinson
 * @since 1.2.0
 * @see UndertowEmbeddedServletContainerFactory
 */
public class UndertowEmbeddedServletContainer implements EmbeddedServletContainer {

    private static final Log logger = LogFactory.getLog(UndertowEmbeddedServletContainer.class);

    private final Builder builder;

    private final DeploymentManager manager;

    private final String contextPath;

    private final boolean useForwardHeaders;

    private final boolean autoStart;

    private final Compression compression;

    private Undertow undertow;

    private boolean started = false;

    public UndertowEmbeddedServletContainer(Builder builder, DeploymentManager manager, String contextPath,
            int port, boolean autoStart, Compression compression) {
        this(builder, manager, contextPath, port, false, autoStart, compression);
    }

    public UndertowEmbeddedServletContainer(Builder builder, DeploymentManager manager, String contextPath,
            int port, boolean useForwardHeaders, boolean autoStart, Compression compression) {
        this.builder = builder;
        this.manager = manager;
        this.contextPath = contextPath;
        this.useForwardHeaders = useForwardHeaders;
        this.autoStart = autoStart;
        this.compression = compression;
    }

    @Override
    public synchronized void start() throws EmbeddedServletContainerException {
        try {
            if (!this.autoStart) {
                return;
            }
            if (this.undertow == null) {
                this.undertow = createUndertowServer();
            }
            this.undertow.start();
            this.started = true;
            UndertowEmbeddedServletContainer.logger.info("Undertow started on port(s) " + getPortsDescription());
        } catch (ServletException ex) {
            throw new EmbeddedServletContainerException("Unable to start embdedded Undertow", ex);
        }
    }

    private Undertow createUndertowServer() throws ServletException {
        HttpHandler httpHandler = this.manager.start();
        httpHandler = getContextHandler(httpHandler);
        if (this.useForwardHeaders) {
            httpHandler = Handlers.proxyPeerAddress(httpHandler);
        }
        this.builder.setHandler(httpHandler);
        return this.builder.build();
    }

    private HttpHandler getContextHandler(HttpHandler httpHandler) {
        HttpHandler contextHandler = configurationCompressionIfNecessary(httpHandler);
        if (StringUtils.isEmpty(this.contextPath)) {
            return contextHandler;
        }
        return Handlers.path().addPrefixPath(this.contextPath, contextHandler);
    }

    private HttpHandler configurationCompressionIfNecessary(HttpHandler httpHandler) {
        if (this.compression == null || !this.compression.getEnabled()) {
            return httpHandler;
        }
        ContentEncodingRepository repository = new ContentEncodingRepository();
        repository.addEncodingHandler("gzip", new GzipEncodingProvider(), 50,
                Predicates.and(getCompressionPredicates(this.compression)));
        return new EncodingHandler(repository).setNext(httpHandler);
    }

    private Predicate[] getCompressionPredicates(Compression compression) {
        List<Predicate> predicates = new ArrayList<Predicate>();
        predicates.add(Predicates.maxContentSize(compression.getMinResponseSize()));
        predicates.add(new CompressibleMimeTypePredicate(compression.getMimeTypes()));
        if (compression.getExcludedUserAgents() != null) {
            for (String agent : compression.getExcludedUserAgents()) {
                RequestHeaderAttribute agentHeader = new RequestHeaderAttribute(
                        new HttpString(HttpHeaders.USER_AGENT));
                predicates.add(Predicates.not(Predicates.regex(agentHeader, agent)));
            }
        }
        return predicates.toArray(new Predicate[predicates.size()]);
    }

    private String getPortsDescription() {
        List<Port> ports = getPorts();
        if (!ports.isEmpty()) {
            return StringUtils.collectionToDelimitedString(ports, " ");
        }
        return "unknown";
    }

    private List<Port> getPorts() {
        List<Port> ports = new ArrayList<Port>();
        try {
            if (!this.autoStart) {
                ports.add(new 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 Port getPortFromChannel(BoundChannel channel) {
        String protocol = ReflectionUtils.findField(channel.getClass(), "ssl") != null ? "https" : "http";
        SocketAddress socketAddress = channel.getLocalAddress();
        if (socketAddress instanceof InetSocketAddress) {
            return new Port(((InetSocketAddress) socketAddress).getPort(), protocol);
        }
        return null;
    }

    @Override
    public synchronized void stop() throws EmbeddedServletContainerException {
        if (this.started) {
            try {
                this.started = false;
                this.manager.stop();
                this.undertow.stop();
            } catch (Exception ex) {
                throw new EmbeddedServletContainerException("Unable to stop undertow", ex);
            }
        }
    }

    @Override
    public int getPort() {
        List<Port> ports = getPorts();
        if (ports.isEmpty()) {
            return 0;
        }
        return ports.get(0).getNumber();
    }

    /**
     * An active undertow port.
     */
    private final static 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 String toString() {
            return this.number + " (" + this.protocol + ")";
        }

    }

    private static class CompressibleMimeTypePredicate implements Predicate {

        private final List<MimeType> mimeTypes;

        CompressibleMimeTypePredicate(String[] mimeTypes) {
            this.mimeTypes = new ArrayList<MimeType>(mimeTypes.length);
            for (String mimeTypeString : mimeTypes) {
                this.mimeTypes.add(MimeTypeUtils.parseMimeType(mimeTypeString));
            }
        }

        @Override
        public boolean resolve(HttpServerExchange value) {
            String contentType = value.getResponseHeaders().getFirst(HttpHeaders.CONTENT_TYPE);
            if (contentType != null) {
                for (MimeType mimeType : this.mimeTypes) {
                    if (mimeType.isCompatibleWith(MimeTypeUtils.parseMimeType(contentType))) {
                        return true;
                    }
                }
            }
            return false;
        }

    }

}