io.cloudracer.mocktcpserver.MockTCPServer Maven / Gradle / Ivy
package io.cloudracer.mocktcpserver;
import java.io.BufferedReader;
import java.io.Closeable;
import java.io.DataOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;
import java.util.Arrays;
import java.util.concurrent.TimeUnit;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.DefaultParser;
import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;
import org.apache.commons.configuration2.ex.ConfigurationException;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.junit.Assert;
import io.cloudracer.mocktcpserver.datastream.DataStream;
import io.cloudracer.mocktcpserver.datastream.DataStreamRegexMatcher;
import io.cloudracer.properties.ConfigurationSettings;
/**
* A TCP Server that is designed to simulate success and failure conditions in System/Integration test environments.
*
* @author John McDonnell
*/
public class MockTCPServer extends Thread implements Closeable {
private final Logger logger = LogManager.getLogger(this.getRootLoggerName());
private enum Status {
OPEN, CLOSING, CLOSED
}
private static final byte[] DEFAULT_TERMINATOR = { 13, 10, 10 };
private static final byte[] DEFAULT_ACK = { 65 };
private static final byte[] DEFAULT_NAK = { 78 };
private byte[] terminator = null;
private byte[] ack = null;
private byte[] nak = null;
private AssertionError assertionError;
private ServerSocket socket;
private BufferedReader inputStream;
private DataOutputStream outputStream;
private DataStreamRegexMatcher expectedMessage;
private DataStream dataStream;
private Socket connectionSocket;
private Integer port;
private boolean setIsAlwaysNAKResponse = false;
private boolean setIsAlwaysNoResponse = false;
private boolean isCloseAfterNextResponse = false;
private int messagesReceivedCount = 0;
private Status status = Status.OPEN;
private final ConfigurationSettings configurationSettings = new ConfigurationSettings();
private abstract static class Print {
private static final Logger logger = LogManager.getLogger(Print.class.getName());
private Print() {
// Do nothing. This class cannot be constructed.
}
private static void printVersion() {
final String ideWorkingFolder = "classes";
final File executableLocation = new File(MockTCPServer.class.getProtectionDomain()
.getCodeSource()
.getLocation()
.getPath());
String version = executableLocation.getName();
// If this is the IDE, use the full path.
if (version.equals(ideWorkingFolder)) {
version = executableLocation.getAbsoluteFile().toString();
}
final Pattern pattern = Pattern.compile("\\d+\\.\\d+\\.\\d+");
final Matcher matcher = pattern.matcher(version);
if (matcher.find()) {
logger.info(matcher.group(0));
} else {
logger.info("Version number cannot be identified.");
}
}
private static void printHelp() {
printHelp(null);
}
private static void printHelp(final ParseException e1) {
if (e1 != null) {
logger.info(String.format("Invalid command line: %s", e1.getMessage()));
}
// automatically generate the help statement
final HelpFormatter formatter = new HelpFormatter();
formatter.printHelp("MockTCPServer", getCommandLineOptions());
}
}
/**
* Start the server on the default port. This constructor is the equivalent of passing null to the constructor {@link MockTCPServer#MockTCPServer(Integer)}.
*/
public MockTCPServer() {
this(null);
}
/**
* Start the server on the specified port.
*
* @param port the TCP Server will listen on this port. If null, the default port will be used.
*/
public MockTCPServer(final Integer port) {
this.logger.info("Starting...");
if (port != null) {
this.setPort(port);
}
super.setName(String.format("%s-%d", this.getThreadName(), this.getPort()));
this.start();
/*
* If this pause is not done here, a test that *immediately* tries to connect, may get a "connection refused" error.
*/
try {
final long sleepDuration = 20;
TimeUnit.MILLISECONDS.sleep(sleepDuration);
} catch (final InterruptedException e) {
Thread.currentThread().interrupt();
}
}
/**
* This allows an operator to start a stand-alone MockTCPServer. The startup.sh(cmd) file can be used to start the server on a command-line.
*
* Note: currently, there is no packaged bundle to include all the dependencies and scripts.
*
* @param args an alternative port number can be passed as the first (and only) parameter.
*/
public static void main(String[] args) {
final Logger logger = LogManager.getLogger();
try {
final CommandLine commandLine = new DefaultParser().parse(getCommandLineOptions(), args);
// Version information only.
if (commandLine.hasOption("version")) {
Print.printVersion();
} else if (commandLine.hasOption("help")) {
Print.printHelp();
} else {
final MockTCPServer mockTCPServer;
if (commandLine.hasOption("port")) {
final int port = Integer.parseInt(commandLine.getOptionValue("port"));
mockTCPServer = new MockTCPServer(port);
} else {
mockTCPServer = new MockTCPServer();
}
// When the Operating System interrupts the thread (kill or CTRL-C), stop the server.
Runtime.getRuntime().addShutdownHook(new Thread() {
@Override
public void run() {
logger.info("Operating System interrupt detected.");
mockTCPServer.close();
}
});
try {
waitForThread(logger, mockTCPServer, 0);
} finally {
IOUtils.closeQuietly(mockTCPServer);
}
}
} catch (final ParseException e1) {
Print.printHelp(e1);
}
}
private static void waitForThread(final Logger logger, final Thread thread, final long maximumDurationToWait) {
try {
thread.join(maximumDurationToWait);
} catch (final InterruptedException e) {
logger.warn(e);
Thread.currentThread().interrupt();
}
}
@Override
public void run() {
try {
while (this.getStatus() == Status.OPEN && this.getSocket() != null) {
this.readIncomingStream();
}
} catch (final SocketException e) {
this.logger.warn(e);
} catch (final Exception e) {
this.logger.error(e.getMessage(), e);
} finally {
this.setStatus(Status.CLOSING);
this.close();
}
}
private void readIncomingStream() throws IOException {
this.setDataStream(null);
while (this.getDataStream().write(this.getInputStream().read()) != -1) {
if (Arrays.equals(this.getDataStream().getTail(), this.getTerminator())) {
this.incrementMessagesReceivedCount();
break;
}
}
if (this.getDataStream().getLastByte() == -1) {
// The stream has ended so close all streams so that a new ServerSocket is opened and a new connection can be accepted.
this.closeStreams();
} else if (this.getDataStream().size() > 0) { // Ignore null (i.e. zero length) in order allow a probing ping e.g. paping.exe
this.processIncomingMessage();
}
}
private void processIncomingMessage() throws IOException {
this.setAssertionError(null);
try {
if (this.getExpectedMessage() != null) {
Assert.assertThat("Unexpected message from the AM Host Client.", this.getDataStream(), this.getExpectedMessage());
}
} catch (final AssertionError e) {
this.setAssertionError(e);
}
this.onMessage(this.getDataStream());
// If the stream has not ended and a response is required, send one.
if (this.getDataStream().getLastByte() != -1 && !this.getIsAlwaysNoResponse()) {
byte[] response;
if (this.getAssertionError() == null && !this.getIsAlwaysNAKResponse()) {
response = this.getACK();
} else {
response = this.getNAK();
}
this.getOutputStream().write(response);
this.afterResponse(response);
}
}
/**
* The server will read the stream until these characters are encountered.
*
* @return the terminator.
*/
public byte[] getTerminator() {
if (this.terminator == null) {
this.terminator = MockTCPServer.DEFAULT_TERMINATOR;
}
return this.terminator;
}
/**
* The server will read the stream until these characters are encountered.
*
* @param terminator the terminator.
*/
public synchronized void setTerminator(final byte[] terminator) {
this.terminator = terminator;
}
/**
* The positive acknowledgement response.
*
* @return positive acknowledgement
*/
public byte[] getACK() {
if (this.ack == null) {
this.ack = MockTCPServer.DEFAULT_ACK;
}
return this.ack;
}
/**
* The positive acknowledgement response.
*
* @param ack positive acknowledgement
*/
public synchronized void setACK(final byte[] ack) {
this.ack = ack;
}
/**
* The negative acknowledgement response.
*
* @return negative acknowledgement
*/
public byte[] getNAK() {
if (this.nak == null) {
this.nak = MockTCPServer.DEFAULT_NAK;
}
return this.nak;
}
/**
* The negative acknowledgement response.
*
* @param nak negative acknowledgement
*/
public synchronized void setNAK(final byte[] nak) {
this.nak = nak;
}
/**
* A server callback when a message has been processed, and a response has been sent to the client.
*
* @param response the response that has been sent.
*/
public synchronized void afterResponse(final byte[] response) {
this.logger.debug(String.format("Sent the response: %s.", new String(response)));
if (this.getIsCloseAfterNextResponse()) {
this.setStatus(Status.CLOSED);
}
}
/**
* A server callback when a message is received.
*
* @param message the message received.
*/
public void onMessage(final DataStream message) {
this.logger.info(String.format("Received: %s.", message.toString()));
}
/**
* An error is recorded if a message other than that which is expected is received.
*
* @return a recorded error.
*/
public AssertionError getAssertionError() {
return this.assertionError;
}
/**
* An error will be recorded if a message other than that which is {@link MockTCPServer#getAssertionError() expected} is received.
*
* @param assertionError a recorded error.
*/
private void setAssertionError(final AssertionError assertionError) {
this.assertionError = assertionError;
}
/**
* Forces the Server to return a NAK in response to the next message received (regardless of any other conditions). The next message will first be processed as normal; irrespective of this property.
*
* This is intended to be used to test a clients response to receiving a NAK.
*
* Default is false.
*
* @return If true, the Servers next response will always be a NAK.
*/
public boolean getIsAlwaysNAKResponse() {
return this.setIsAlwaysNAKResponse;
}
/**
* Forces the Server to return a NAK in response to the next message received (regardless of any other conditions). The next message will first be processed as normal; irrespective of this property.
*
* This is intended to be used to test a clients response to receiving a NAK.
*
* Default is false.
*
* @param isAlwaysNAKResponse if true, the Servers next response will always be a NAK.
*/
public synchronized void setIsAlwaysNAKResponse(final boolean isAlwaysNAKResponse) {
this.setIsAlwaysNAKResponse = isAlwaysNAKResponse;
}
/**
* The server never return a response, when true.
*
* @return true when the server will never return a response. Default is false.
*/
public boolean getIsAlwaysNoResponse() {
return this.setIsAlwaysNoResponse;
}
/**
* The server never return a response, when true.
*
* @param isAlwaysNoResponse true when the server will never return a response. Default is false.
*/
public synchronized void setIsAlwaysNoResponse(final boolean isAlwaysNoResponse) {
this.setIsAlwaysNoResponse = isAlwaysNoResponse;
}
/**
* Forces the Server to close down after processing the next message received (regardless of any other conditions). The next message will first be processed as normal; irrespective of this property.
*
* This is intended to be used so that test clients can wait on the server Thread to end.
*
* Default is false.
*
* @return if true, the Server will close after the message processing is complete. Default is false.
*/
public boolean getIsCloseAfterNextResponse() {
return this.isCloseAfterNextResponse;
}
/**
* Forces the Server to close down after processing the next message received (regardless of any other conditions). The next message will first be processed as normal; irrespective of this property.
*
* This is intended to be used so that test clients can wait on the server Thread to end.
*
* Default is false.
*
* @param isCloseAfterNextResponse if true, the Server will close after the message processing is complete. Default is false.
*/
public synchronized void setIsCloseAfterNextResponse(final boolean isCloseAfterNextResponse) {
this.isCloseAfterNextResponse = isCloseAfterNextResponse;
}
/**
* If any message, other that this one, is the next message to be received, record it as an {@link MockTCPServer#setAssertionError(AssertionError) assertion error}.
*
* @return ignore if null.
*/
public DataStreamRegexMatcher getExpectedMessage() {
return this.expectedMessage;
}
/**
* If any message, other that this one, is the next message to be received, record it as an {@link MockTCPServer#setAssertionError(AssertionError) assertion error} and respond with a {@link MockTCPServer#getNAK() NAK}.
*
* @param expectedMessage a Regular Expression that describes what the next received message will be.
*/
public synchronized void setExpectedMessage(final String expectedMessage) {
this.expectedMessage = new DataStreamRegexMatcher(expectedMessage);
}
/**
* If any message, other that this one, is the next message to be received, record it as an {@link MockTCPServer#setAssertionError(AssertionError) assertion error} and respond with a {@link MockTCPServer#getNAK() NAK}.
*
* @param expectedMessage a Regular Expression that describes what the next received message will be.
*/
public synchronized void setExpectedMessage(final StringBuilder expectedMessage) {
this.setExpectedMessage(expectedMessage.toString());
}
/**
* The number of messages received by the server since the server was started.
*
* @return The number of messages received by the server since the server was started. Default is 0.
*/
public int getMessagesReceivedCount() {
return this.messagesReceivedCount;
}
/**
* Add one to the number of messages received by the server since the server was started. see {@link MockTCPServer#getMessagesReceivedCount()}
*/
private void incrementMessagesReceivedCount() {
this.messagesReceivedCount++;
}
/**
* Close the socket (if it is open) and any open data streams.
*/
@Override
public synchronized void close() {
this.logger.info("Closing...");
if (this.getStatus() != Status.CLOSING) {
this.setStatus(Status.CLOSED);
}
this.closeStreams();
while (super.isAlive() && this.getStatus() != Status.CLOSING) {
final long maximumTimeToWait = 10000;
try {
super.join(maximumTimeToWait);
} catch (final InterruptedException e) {
Thread.currentThread().interrupt();
}
// Intermittently, the server fails to close. Retry it indefinitely until it does close; an improvement of blocking forever with no feedback.
if (super.isAlive()) {
this.logger.warn(String.format("Failed to close the Server(%s) in %d milliseconds. Trying again to shutdown the Server...", super.getName(), maximumTimeToWait));
if (!super.isInterrupted()) {
this.logger.trace(String.format("Interrupting the Server Thread(%s)...", super.getName()));
this.closeStreams();
}
}
}
this.logger.info("Closed.");
}
private void closeStreams() {
try {
if (this.getConnectionSocket() != null && !this.getConnectionSocket().isInputShutdown()) {
this.getConnectionSocket().shutdownInput();
}
if (this.getConnectionSocket() != null && !this.getConnectionSocket().isOutputShutdown()) {
this.getConnectionSocket().shutdownOutput();
}
} catch (final IOException e) {
this.logger.error(e.getMessage(), e);
}
this.setInputStream(null);
this.setOutputStream(null);
// Do not set the ServerSocket to null; just close the Stream.
this.logger.info("Closing the socket...");
IOUtils.closeQuietly(this.socket);
this.logger.info("Closed the socket.");
}
private Status getStatus() {
return this.status;
}
private synchronized void setStatus(final Status status) {
this.status = status;
}
private int getPort() {
try {
if (this.port == null) {
this.port = this.configurationSettings.getPort();
}
} catch (final ConfigurationException e) {
this.logger.error(e.getMessage(), e);
}
return this.port;
}
private void setPort(int port) {
this.port = port;
}
/**
* Open the Server Socket and wait for a connection.
*
* The socket is opened on the configured {@link #getPort() port} on localhost.
*
* @return a new ServerSocket.
* @throws IOException
* @throws ConfigurationException
*/
private ServerSocket getSocket() throws IOException, ConfigurationException {
if (this.socket == null || this.socket.isClosed()) {
this.logger.info(String.format("Opening a socket on port %d...", this.getPort()));
this.setSocket(new ServerSocket(this.getPort()));
this.logger.info("Waiting for a connection...");
this.setConnectionSocket(this.socket.accept());
this.logger.info("Accepted a connection.");
this.setInputStream(new BufferedReader(new InputStreamReader(this.getConnectionSocket().getInputStream())));
this.setOutputStream(new DataOutputStream(this.getConnectionSocket().getOutputStream()));
this.logger.info("Ready to receive input.");
}
return this.socket;
}
private void setSocket(final ServerSocket socket) {
this.socket = socket;
}
private Socket getConnectionSocket() {
return this.connectionSocket;
}
private void setConnectionSocket(final Socket connectionSocket) {
this.connectionSocket = connectionSocket;
}
private DataStream getDataStream() {
if (this.dataStream == null) {
this.dataStream = new DataStream(this.getTerminator().length, this.getRootLoggerName());
}
return this.dataStream;
}
private void setDataStream(final DataStream dataStream) {
this.logger.debug("Closing the DataStream...");
IOUtils.closeQuietly(this.dataStream);
this.logger.debug("Closed the DataStream.");
this.dataStream = dataStream;
}
private BufferedReader getInputStream() {
return this.inputStream;
}
private void setInputStream(final BufferedReader inputStream) {
this.logger.info("Closing input stream...");
IOUtils.closeQuietly(this.inputStream);
this.logger.info("Closed input stream.");
this.inputStream = inputStream;
}
private DataOutputStream getOutputStream() {
return this.outputStream;
}
private void setOutputStream(final DataOutputStream outputStream) {
this.logger.info("Closing the output stream...");
IOUtils.closeQuietly(this.outputStream);
this.logger.info("Closed the output stream.");
this.outputStream = outputStream;
}
private static Options getCommandLineOptions() {
// create the Options
final Options options = new Options();
options.addOption("p", "port", false, "use this port instead of the default one, or the one specified in the configuration file.");
options.getOption("port").setArgs(1);
options.addOption("h", "help", false, "print these usage instructions and exit.");
options.addOption("?", "help", false, "print these usage instructions and exit.");
options.addOption("v", "version", false, "print product version and exit.");
return options;
}
/**
* The log4j root logger name that will contain the class name, even if instantiated as an anonymous class.
*
* @return a root logger name.
*/
public String getRootLoggerName() {
return this.getThreadName().replaceAll("-", ".");
}
/**
* Derives a {@link Thread#getName() Thread name} that includes the class name, even if this object instantiated as an anonymous class.
*
* @return a value used as the log4j root logger and the Thread name.
*/
private String getThreadName() {
final String delimeter = ".";
final String regEx = "\\.";
String name;
if (StringUtils.isNotBlank(this.getClass().getSimpleName())) {
name = this.getClass().getSimpleName();
} else {
if (this.getClass().getName().contains(delimeter)) {
final String[] nameSegments = this.getClass().getName().split(regEx);
name = String.format("%s-%s", this.getClass().getSuperclass().getSimpleName(), nameSegments[nameSegments.length - 1]);
} else {
name = this.getClass().getName();
}
}
return name;
}
}