org.springframework.boot.devtools.livereload.LiveReloadServer Maven / Gradle / Ivy
/*
* Copyright 2012-2024 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
*
* https://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.devtools.livereload;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketTimeoutException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.core.log.LogMessage;
import org.springframework.util.Assert;
/**
* A livereload server.
*
* @author Phillip Webb
* @since 1.3.0
*/
public class LiveReloadServer {
/**
* The default live reload server port.
*/
public static final int DEFAULT_PORT = 35729;
private static final Log logger = LogFactory.getLog(LiveReloadServer.class);
private static final int READ_TIMEOUT = (int) TimeUnit.SECONDS.toMillis(4);
private final ExecutorService executor = Executors.newCachedThreadPool(new WorkerThreadFactory());
private final List connections = new ArrayList<>();
private final Object monitor = new Object();
private final int port;
private final ThreadFactory threadFactory;
private ServerSocket serverSocket;
private Thread listenThread;
/**
* Create a new {@link LiveReloadServer} listening on the default port.
*/
public LiveReloadServer() {
this(DEFAULT_PORT);
}
/**
* Create a new {@link LiveReloadServer} listening on the default port with a specific
* {@link ThreadFactory}.
* @param threadFactory the thread factory
*/
public LiveReloadServer(ThreadFactory threadFactory) {
this(DEFAULT_PORT, threadFactory);
}
/**
* Create a new {@link LiveReloadServer} listening on the specified port.
* @param port the listen port
*/
public LiveReloadServer(int port) {
this(port, Thread::new);
}
/**
* Create a new {@link LiveReloadServer} listening on the specified port with a
* specific {@link ThreadFactory}.
* @param port the listen port
* @param threadFactory the thread factory
*/
public LiveReloadServer(int port, ThreadFactory threadFactory) {
this.port = port;
this.threadFactory = threadFactory;
}
/**
* Start the livereload server and accept incoming connections.
* @return the port on which the server is listening
* @throws IOException in case of I/O errors
*/
public int start() throws IOException {
synchronized (this.monitor) {
Assert.state(!isStarted(), "Server already started");
logger.debug(LogMessage.format("Starting live reload server on port %s", this.port));
this.serverSocket = new ServerSocket(this.port);
int localPort = this.serverSocket.getLocalPort();
this.listenThread = this.threadFactory.newThread(this::acceptConnections);
this.listenThread.setDaemon(true);
this.listenThread.setName("Live Reload Server");
this.listenThread.start();
return localPort;
}
}
/**
* Return if the server has been started.
* @return {@code true} if the server is running
*/
public boolean isStarted() {
synchronized (this.monitor) {
return this.listenThread != null;
}
}
/**
* Return the port that the server is listening on.
* @return the server port
*/
public int getPort() {
return this.port;
}
private void acceptConnections() {
do {
try {
Socket socket = this.serverSocket.accept();
socket.setSoTimeout(READ_TIMEOUT);
this.executor.execute(new ConnectionHandler(socket));
}
catch (SocketTimeoutException ex) {
// Ignore
}
catch (Exception ex) {
if (logger.isDebugEnabled()) {
logger.debug("LiveReload server error", ex);
}
}
}
while (!this.serverSocket.isClosed());
}
/**
* Gracefully stop the livereload server.
* @throws IOException in case of I/O errors
*/
public void stop() throws IOException {
synchronized (this.monitor) {
if (this.listenThread != null) {
closeAllConnections();
try {
this.executor.shutdown();
this.executor.awaitTermination(1, TimeUnit.MINUTES);
}
catch (InterruptedException ex) {
Thread.currentThread().interrupt();
}
this.serverSocket.close();
try {
this.listenThread.join();
}
catch (InterruptedException ex) {
Thread.currentThread().interrupt();
}
this.listenThread = null;
this.serverSocket = null;
}
}
}
private void closeAllConnections() throws IOException {
synchronized (this.connections) {
for (Connection connection : this.connections) {
connection.close();
}
}
}
/**
* Trigger livereload of all connected clients.
*/
public void triggerReload() {
synchronized (this.monitor) {
synchronized (this.connections) {
for (Connection connection : this.connections) {
try {
connection.triggerReload();
}
catch (Exception ex) {
logger.debug("Unable to send reload message", ex);
}
}
}
}
}
private void addConnection(Connection connection) {
synchronized (this.connections) {
this.connections.add(connection);
}
}
private void removeConnection(Connection connection) {
synchronized (this.connections) {
this.connections.remove(connection);
}
}
/**
* Factory method used to create the {@link Connection}.
* @param socket the source socket
* @param inputStream the socket input stream
* @param outputStream the socket output stream
* @return a connection
* @throws IOException in case of I/O errors
*/
protected Connection createConnection(Socket socket, InputStream inputStream, OutputStream outputStream)
throws IOException {
return new Connection(socket, inputStream, outputStream);
}
/**
* {@link Runnable} to handle a single connection.
*
* @see Connection
*/
private class ConnectionHandler implements Runnable {
private final Socket socket;
private final InputStream inputStream;
ConnectionHandler(Socket socket) throws IOException {
this.socket = socket;
this.inputStream = socket.getInputStream();
}
@Override
public void run() {
try {
handle();
}
catch (ConnectionClosedException ex) {
logger.debug("LiveReload connection closed");
}
catch (Exception ex) {
if (logger.isDebugEnabled()) {
logger.debug("LiveReload error", ex);
}
}
}
private void handle() throws Exception {
try {
try (OutputStream outputStream = this.socket.getOutputStream()) {
Connection connection = createConnection(this.socket, this.inputStream, outputStream);
runConnection(connection);
}
finally {
this.inputStream.close();
}
}
finally {
this.socket.close();
}
}
private void runConnection(Connection connection) throws Exception {
try {
addConnection(connection);
connection.run();
}
finally {
removeConnection(connection);
}
}
}
/**
* {@link ThreadFactory} to create the worker threads.
*/
private static final class WorkerThreadFactory implements ThreadFactory {
private final AtomicInteger threadNumber = new AtomicInteger(1);
@Override
public Thread newThread(Runnable r) {
Thread thread = new Thread(r);
thread.setDaemon(true);
thread.setName("Live Reload #" + this.threadNumber.getAndIncrement());
return thread;
}
}
}