Merge pull request #3 from informatik-ag-ngl/b/cancelled_socket

Fixed unresponsive behavior after cancelled socket

.github/workflows/maven.yml

@@ -0,0 +1,17 @@
+name: Java CI
+
+on: [push]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up JDK 1.8
+      uses: actions/setup-java@v1
+      with:
+        java-version: 1.8
+    - name: Build with Maven
+      run: mvn -B package --file pom.xml

.settings/org.eclipse.core.resources.prefs

@@ -0,0 +1,4 @@
+eclipse.preferences.version=1
+encoding//src/main/java=UTF-8
+encoding//src/test/java=UTF-8
+encoding/<project>=UTF-8

.settings/org.eclipse.jdt.core.prefs

@@ -4,5 +4,5 @@ org.eclipse.jdt.core.compiler.compliance=1.8
 org.eclipse.jdt.core.compiler.problem.enablePreviewFeatures=disabled
 org.eclipse.jdt.core.compiler.problem.forbiddenReference=warning
 org.eclipse.jdt.core.compiler.problem.reportPreviewFeatures=ignore
-org.eclipse.jdt.core.compiler.release=enabled
+org.eclipse.jdt.core.compiler.release=disabled
 org.eclipse.jdt.core.compiler.source=1.8

pom.xml

@@ -2,10 +2,21 @@
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
+
 	<groupId>informatik-ag-ngl</groupId>
 	<artifactId>java-nio-server</artifactId>
 	<version>0.0.1-SNAPSHOT</version>
 
+	<name>java-nio-server</name>
+	<url>https://github.com/informatik-ag-ngl/java-nio-server</url>
+
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+		<maven.compiler.source>1.8</maven.compiler.source>
+		<maven.compiler.target>1.8</maven.compiler.target>
+	</properties>
+
 	<dependencies>
 		<dependency>
 			<groupId>org.junit.jupiter</groupId>
@@ -16,13 +27,33 @@
 	</dependencies>
 
 	<build>
+		<finalName>java-nio-server</finalName>
 		<plugins>
 			<plugin>
-				<artifactId>maven-compiler-plugin</artifactId>
+				<groupId>org.apache.maven.plugins</groupId>
-				<version>3.8.0</version>
+				<artifactId>maven-source-plugin</artifactId>
-				<configuration>
+				<version>3.2.1</version>
-					<release>8</release>
+				<executions>
-				</configuration>
+					<execution>
+						<id>attach-sources</id>
+						<goals>
+							<goal>jar</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-javadoc-plugin</artifactId>
+				<version>3.1.1</version>
+				<executions>
+					<execution>
+						<id>attach-javadocs</id>
+						<goals>
+							<goal>jar</goal>
+						</goals>
+					</execution>
+				</executions>
 			</plugin>
 		</plugins>
 	</build>

src/main/java/com/jenkov/nioserver/ISocketIdListener.java

@@ -0,0 +1,25 @@
+package com.jenkov.nioserver;
+
+/**
+ * Project: <strong>java-nio-server</strong><br>
+ * File: <strong>ISocketIdListener.java</strong><br>
+ * Created: <strong>03.01.2020</strong><br>
+ * 
+ * @author Kai S. K. Engelbart
+ */
+public interface ISocketIdListener {
+
+	/**
+	 * Is invoked when a new {@link Socket} is registered by the server
+	 * 
+	 * @param socketId the ID of the newly registered socket
+	 */
+	void socketRegistered(long socketId);
+
+	/**
+	 * Is invoked when a {@link Socket} is cancelled by the server
+	 * 
+	 * @param socketId the ID of the cancelled socket
+	 */
+	void socketCancelled(long socketId);
+}

src/main/java/com/jenkov/nioserver/Message.java

@@ -68,7 +68,7 @@ public class Message {
 			if (!this.messageBuffer.expandMessage(this)) return -1;
 
 		int bytesToCopy = Math.min(remaining, capacity - length);
-		System.arraycopy(byteArray, offset, sharedArray, offset + this.length, bytesToCopy);
+		System.arraycopy(byteArray, offset, sharedArray, this.offset + this.length, bytesToCopy);
 		this.length += bytesToCopy;
 		return bytesToCopy;
 	}

src/main/java/com/jenkov/nioserver/MessageWriter.java

@@ -19,8 +19,10 @@ public class MessageWriter {
 	private int				bytesWritten;
 
 	public void enqueue(Message message) {
-		if (messageInProgress == null) messageInProgress = message;
+		if (messageInProgress == null) {
-		else writeQueue.add(message);
+			messageInProgress	= message;
+			bytesWritten		= 0;
+		} else writeQueue.add(message);
 	}
 
 	public void write(Socket socket, ByteBuffer byteBuffer) throws IOException {
@@ -31,8 +33,10 @@ public class MessageWriter {
 		byteBuffer.clear();
 
 		if (bytesWritten >= messageInProgress.length) {
-			if (writeQueue.size() > 0) messageInProgress = writeQueue.remove(0);
+			if (writeQueue.size() > 0) {
-			else messageInProgress = null;
+				messageInProgress	= writeQueue.remove(0);
+				bytesWritten		= 0;
+			} else messageInProgress = null;
 			// TODO: unregister from selector
 		}
 	}

src/main/java/com/jenkov/nioserver/Server.java

@@ -13,7 +13,7 @@ import java.util.concurrent.ArrayBlockingQueue;
  */
 public class Server {
 
-	private SocketAcceptor	socketAccepter;
+	private SocketAcceptor	socketAcceptor;
 	private SocketProcessor	socketProcessor;
 
 	private int						tcpPort;
@@ -30,17 +30,21 @@ public class Server {
 
 		Queue<Socket> socketQueue = new ArrayBlockingQueue<>(1024); // TODO: move 1024 to ServerConfig
 
-		socketAccepter = new SocketAcceptor(tcpPort, socketQueue);
+		socketAcceptor = new SocketAcceptor(tcpPort, socketQueue);
 
 		MessageBuffer	readBuffer	= new MessageBuffer();
 		MessageBuffer	writeBuffer	= new MessageBuffer();
 
 		socketProcessor = new SocketProcessor(socketQueue, readBuffer, writeBuffer, this.messageReaderFactory, this.messageProcessor);
 
-		Thread	accepterThread	= new Thread(socketAccepter);
+		Thread	accepterThread	= new Thread(socketAcceptor);
 		Thread	processorThread	= new Thread(socketProcessor);
 
 		accepterThread.start();
 		processorThread.start();
 	}
+
+	public SocketAcceptor getSocketAcceptor() { return socketAcceptor; }
+
+	public SocketProcessor getSocketProcessor() { return socketProcessor; }
 }

src/main/java/com/jenkov/nioserver/Socket.java

@@ -47,5 +47,4 @@ public class Socket {
 
 		return totalBytesWritten;
 	}
-
 }

src/main/java/com/jenkov/nioserver/SocketProcessor.java

@@ -5,14 +5,7 @@ import java.nio.ByteBuffer;
 import java.nio.channels.ClosedChannelException;
 import java.nio.channels.SelectionKey;
 import java.nio.channels.Selector;
-import java.util.HashMap;
+import java.util.*;
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Map;
-import java.util.Queue;
-import java.util.Set;
 
 /**
  * Project: <strong>java-nio-server</strong><br>
@@ -51,13 +44,15 @@ public class SocketProcessor implements Runnable {
 	private Set<Socket>	emptyToNonEmptySockets	= new HashSet<>();
 	private Set<Socket>	nonEmptyToEmptySockets	= new HashSet<>();
 
+	private Set<ISocketIdListener> socketIdListeners = new HashSet<>();
+
 	public SocketProcessor(Queue<Socket> inboundSocketQueue, MessageBuffer readMessageBuffer, MessageBuffer writeMessageBuffer,
 			IMessageReaderFactory messageReaderFactory, IMessageProcessor messageProcessor) throws IOException {
 		this.inboundSocketQueue = inboundSocketQueue;
 
 		this.readMessageBuffer	= readMessageBuffer;
 		this.writeMessageBuffer	= writeMessageBuffer;
-		writeProxy				= new WriteProxy(writeMessageBuffer, this.outboundMessageQueue);
+		writeProxy				= new WriteProxy(writeMessageBuffer, outboundMessageQueue);
 
 		this.messageReaderFactory = messageReaderFactory;
 
@@ -67,6 +62,7 @@ public class SocketProcessor implements Runnable {
 		writeSelector	= Selector.open();
 	}
 
+	@Override
 	public void run() {
 		while (true) {
 			try {
@@ -97,6 +93,7 @@ public class SocketProcessor implements Runnable {
 			newSocket.messageWriter = new MessageWriter();
 
 			socketMap.put(newSocket.socketId, newSocket);
+			socketIdListeners.forEach(l -> l.socketRegistered(nextSocketId - 1));
 
 			SelectionKey key = newSocket.socketChannel.register(readSelector, SelectionKey.OP_READ);
 			key.attach(newSocket);
@@ -109,7 +106,7 @@ public class SocketProcessor implements Runnable {
 		int readReady = readSelector.selectNow();
 
 		if (readReady > 0) {
-			Set<SelectionKey>		selectedKeys	= this.readSelector.selectedKeys();
+			Set<SelectionKey>		selectedKeys	= readSelector.selectedKeys();
 			Iterator<SelectionKey>	keyIterator		= selectedKeys.iterator();
 
 			while (keyIterator.hasNext()) {
@@ -121,28 +118,42 @@ public class SocketProcessor implements Runnable {
 		}
 	}
 
+	public void registerSocketIdListener(ISocketIdListener listener) {
+		socketIdListeners.add(listener);
+	}
+
 	private void readFromSocket(SelectionKey key) throws IOException {
 		Socket socket = (Socket) key.attachment();
-		socket.messageReader.read(socket, this.readByteBuffer);
+		boolean	cancelled	= false;
+
+		try {
+			socket.messageReader.read(socket, readByteBuffer);
 
 			List<Message> fullMessages = socket.messageReader.getMessages();
 			if (fullMessages.size() > 0) {
 				for (Message message : fullMessages) {
 					message.socketId = socket.socketId;
-				messageProcessor.process(message, writeProxy); // the message processor will eventually push outgoing messages into an
+					// the message processor will eventually push outgoing messages into an
 					// IMessageWriter for this socket.
+					messageProcessor.process(message, writeProxy);
 				}
 				fullMessages.clear();
 			}
-
+		} catch (IOException e) {
-		if (socket.endOfStreamReached) {
+			e.printStackTrace();
+			System.err.println("An exception occurred while reading from a socket. Cancelling socket...");
+			cancelled = true;
+		} finally {
+			if (cancelled || socket.endOfStreamReached) {
 				System.out.println("Socket closed: " + socket.socketId);
 				socketMap.remove(socket.socketId);
+				socketIdListeners.forEach(l -> l.socketCancelled(socket.socketId));
 				key.attach(null);
 				key.cancel();
 				key.channel().close();
 			}
 		}
+	}
 
 	public void writeToSockets() throws IOException {
 
@@ -156,10 +167,10 @@ public class SocketProcessor implements Runnable {
 		registerNonEmptySockets();
 
 		// Select from the Selector.
-		int writeReady = this.writeSelector.selectNow();
+		int writeReady = writeSelector.selectNow();
 
 		if (writeReady > 0) {
-			Set<SelectionKey>		selectionKeys	= this.writeSelector.selectedKeys();
+			Set<SelectionKey>		selectionKeys	= writeSelector.selectedKeys();
 			Iterator<SelectionKey>	keyIterator		= selectionKeys.iterator();
 
 			while (keyIterator.hasNext()) {
@@ -167,9 +178,9 @@ public class SocketProcessor implements Runnable {
 
 				Socket socket = (Socket) key.attachment();
 
-				socket.messageWriter.write(socket, this.writeByteBuffer);
+				socket.messageWriter.write(socket, writeByteBuffer);
 
-				if (socket.messageWriter.isEmpty()) { this.nonEmptyToEmptySockets.add(socket); }
+				if (socket.messageWriter.isEmpty()) { nonEmptyToEmptySockets.add(socket); }
 
 				keyIterator.remove();
 			}
@@ -185,7 +196,7 @@ public class SocketProcessor implements Runnable {
 
 	private void cancelEmptySockets() {
 		for (Socket socket : nonEmptyToEmptySockets) {
-			SelectionKey key = socket.socketChannel.keyFor(this.writeSelector);
+			SelectionKey key = socket.socketChannel.keyFor(writeSelector);
 			key.cancel();
 		}
 		nonEmptyToEmptySockets.clear();