org.springframework.boot.web.embedded.netty.NettyWebServer.java Source code

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Here is the source code for org.springframework.boot.web.embedded.netty.NettyWebServer.java

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/*
 * 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.netty;

import java.time.Duration;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import reactor.netty.ChannelBindException;
import reactor.netty.DisposableServer;
import reactor.netty.http.server.HttpServer;

import org.springframework.boot.web.server.PortInUseException;
import org.springframework.boot.web.server.WebServer;
import org.springframework.boot.web.server.WebServerException;
import org.springframework.http.server.reactive.ReactorHttpHandlerAdapter;
import org.springframework.util.Assert;

/**
 * {@link WebServer} that can be used to control a Reactor Netty web server. Usually this
 * class should be created using the {@link NettyReactiveWebServerFactory} and not
 * directly.
 *
 * @author Brian Clozel
 * @author Madhura Bhave
 * @author Andy Wilkinson
 * @since 2.0.0
 */
public class NettyWebServer implements WebServer {

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

    private final HttpServer httpServer;

    private final ReactorHttpHandlerAdapter handlerAdapter;

    private final Duration lifecycleTimeout;

    private DisposableServer disposableServer;

    public NettyWebServer(HttpServer httpServer, ReactorHttpHandlerAdapter handlerAdapter,
            Duration lifecycleTimeout) {
        Assert.notNull(httpServer, "HttpServer must not be null");
        Assert.notNull(handlerAdapter, "HandlerAdapter must not be null");
        this.httpServer = httpServer;
        this.handlerAdapter = handlerAdapter;
        this.lifecycleTimeout = lifecycleTimeout;
    }

    @Override
    public void start() throws WebServerException {
        if (this.disposableServer == null) {
            try {
                this.disposableServer = startHttpServer();
            } catch (Exception ex) {
                ChannelBindException bindException = findBindException(ex);
                if (bindException != null) {
                    throw new PortInUseException(bindException.localPort());
                }
                throw new WebServerException("Unable to start Netty", ex);
            }
            NettyWebServer.logger.info("Netty started on port(s): " + getPort());
            startDaemonAwaitThread(this.disposableServer);
        }
    }

    private DisposableServer startHttpServer() {
        if (this.lifecycleTimeout != null) {
            return this.httpServer.handle(this.handlerAdapter).bindNow(this.lifecycleTimeout);
        }
        return this.httpServer.handle(this.handlerAdapter).bindNow();
    }

    private ChannelBindException findBindException(Exception ex) {
        Throwable candidate = ex;
        while (candidate != null) {
            if (candidate instanceof ChannelBindException) {
                return (ChannelBindException) candidate;
            }
            candidate = candidate.getCause();
        }
        return null;
    }

    private void startDaemonAwaitThread(DisposableServer disposableServer) {
        Thread awaitThread = new Thread("server") {

            @Override
            public void run() {
                disposableServer.onDispose().block();
            }

        };
        awaitThread.setContextClassLoader(getClass().getClassLoader());
        awaitThread.setDaemon(false);
        awaitThread.start();
    }

    @Override
    public void stop() throws WebServerException {
        if (this.disposableServer != null) {
            if (this.lifecycleTimeout != null) {
                this.disposableServer.disposeNow(this.lifecycleTimeout);
            } else {
                this.disposableServer.disposeNow();
            }
            this.disposableServer = null;
        }
    }

    @Override
    public int getPort() {
        if (this.disposableServer != null) {
            return this.disposableServer.port();
        }
        return 0;
    }

}