I've a very simple application that adds messages to a queue and reads them using a MessagerListener.
Edit: I was testing this on a single instance of Artemis that had been setup as part of a two instance cluster on docker.
I want to create the ConnectionFactory once and reuse it for all producers and consumers in the application.
I have created the ConnectionFactory and stored it in a static variable (singleton) so it can be accessed from anywhere.
The aim is that the client use this shared connection factory to create a new connection when required.
However, I have noticed that doing this causes a "Failed to create session factory" when trying to create a new connection.
javax.jms.JMSException: Failed to create session factory
at org.apache.activemq.artemis.jms.client.ActiveMQConnectionFactory.createConnectionInternal(ActiveMQConnectionFactory.java:886)
at org.apache.activemq.artemis.jms.client.ActiveMQConnectionFactory.createConnection(ActiveMQConnectionFactory.java:299)
at com.test.artemistest.jms.QueueTest2.getMessagesFromQueue(QueueTest2.java:137)
at com.test.artemistest.jms.QueueTest2.access$000(QueueTest2.java:61)
at com.test.artemistest.jms.QueueTest2$1.run(QueueTest2.java:75)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:830)
Caused by: ActiveMQNotConnectedException[errorType=NOT_CONNECTED message=AMQ219007: Cannot connect to server(s). Tried with all available servers.]
at org.apache.activemq.artemis.core.client.impl.ServerLocatorImpl.createSessionFactory(ServerLocatorImpl.java:690)
at org.apache.activemq.artemis.jms.client.ActiveMQConnectionFactory.createConnectionInternal(ActiveMQConnectionFactory.java:884)
If I create a connection factory per call this error does not occur.
Doing this seems very inefficient.
I've recreated a similar issue below.
If I create the connection factory in the main method the error occurs.
However if created just before use in a method it works as expected.
If I add two listeners the error occurs even though they are in separate threads. Could it be linked to the fact the connections are not closed in the consumers but are in the producers?
Why is this the case and do you recommend sharing the connection factory?
Thanks
public class QueueTest2 {
private static boolean shutdown = false;
private static ConnectionFactory cf;
public static void main(String[] args) {
// uncomment below for error to occur
// QueueTest2.getConnectionFactory("localhost", 61616);
ExecutorService executor = Executors.newCachedThreadPool();
executor.execute(new Runnable() {
#Override
public void run() {
getMessagesFromQueue("localhost", 61616);
while (!shutdown) {
try {
Thread.sleep(1000L);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
System.out.println("getMessagesFromQueue shutdown");
}
});
addMessagesToQueue("localhost", 61616);
// uncommenting below also causes the issue
// executor.execute(new Runnable() {
// #Override
// public void run() {
// getMessagesFromQueue("localhost", 61616);
// while (!shutdown) {
// try {
// Thread.sleep(1000L);
// } catch (InterruptedException e) {
// e.printStackTrace();
// }
// }
// System.out.println("getMessagesFromQueue shutdown");
// }
// });
addMessagesToQueue("localhost", 61616);
try {
Thread.sleep(1000L);
} catch (InterruptedException e) {
e.printStackTrace();
}
shutdown = true;
executor.shutdownNow();
}
private static void addMessagesToQueue(String host, int port) {
ConnectionFactory cf2 = getConnectionFactory(host, port);
Connection connection = null;
Session sessionQueue = null;
try {
connection = cf2.createConnection("artemis", "password");
connection.setClientID("Producer");
sessionQueue = connection.createSession(false, Session.CLIENT_ACKNOWLEDGE);
Queue orderQueue = sessionQueue.createQueue("exampleQueue");
MessageProducer producerQueue = sessionQueue.createProducer(orderQueue);
connection.start();
// send 100 messages
for (int i = 0; i < 100; i++) {
TextMessage message = sessionQueue.createTextMessage("This is an order: " + i);
producerQueue.send(message);
}
} catch (JMSException ex) {
Logger.getLogger(QueueTest2.class.getName()).log(Level.SEVERE, null, ex);
} finally {
try {
if (sessionQueue != null) {
sessionQueue.close();
}
} catch (JMSException ex) {
Logger.getLogger(QueueTest2.class.getName()).log(Level.SEVERE, null, ex);
}
try {
if (connection != null) {
connection.close();
}
} catch (JMSException ex) {
Logger.getLogger(QueueTest2.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
private static void getMessagesFromQueue(String host, int port) {
ConnectionFactory cf2 = getConnectionFactory(host, port);
Connection connection2 = null;
Session sessionQueue2;
try {
connection2 = cf2.createConnection("artemis", "password");
connection2.setClientID("Consumer2");
sessionQueue2 = connection2.createSession(false, Session.CLIENT_ACKNOWLEDGE);
Queue orderQueue = sessionQueue2.createQueue("exampleQueue");
MessageConsumer consumerQueue = sessionQueue2.createConsumer(orderQueue);
consumerQueue.setMessageListener(new MessageHandlerTest2());
connection2.start();
Thread.sleep(5000);
} catch (JMSException ex) {
Logger.getLogger(QueueTest2.class.getName()).log(Level.SEVERE, null, ex);
} catch (InterruptedException ex) {
Logger.getLogger(QueueTest2.class.getName()).log(Level.SEVERE, null, ex);
}
}
private static ConnectionFactory getConnectionFactory(String host, int port) {
if (cf == null) {
Map<String, Object> connectionParams2 = new HashMap<String, Object>();
connectionParams2.put(TransportConstants.PORT_PROP_NAME, port);
connectionParams2.put(TransportConstants.HOST_PROP_NAME, host);
TransportConfiguration transportConfiguration = new TransportConfiguration(NettyConnectorFactory.class
.getName(), connectionParams2);
cf = ActiveMQJMSClient.createConnectionFactoryWithoutHA(JMSFactoryType.CF, transportConfiguration);
}
return cf;
}
}
class MessageHandlerTest2 implements MessageListener {
#Override
public void onMessage(Message message) {
try {
System.out.println("new message: " + ((TextMessage) message).getText());
message.acknowledge();
} catch (JMSException ex) {
Logger.getLogger(MessageHandlerTest2.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
I've run your code, but I don't see any errors. My guess is that there may be a timing issue related to concurrency. Try adding synchronized to your getConnectionFactory method since it can theoretically be called concurrently by multiple threads in your application, e.g.:
private synchronized static ConnectionFactory getConnectionFactory(String host, int port)
I have found a solution that works on a clustered environment and docker.
It involves using the "pooled-jms" connection pool. Something I had planned to use anyway.
Although it does not explain the issues I was seeing above, it is at least a work around until I can investigate further.
The "WARN: AMQ212064: Unable to receive cluster topology " mentioned above appears to have been a red herring as it went away as quickly as it appeared.
I was trying to log the number of current active connections. I am using com.zaxxer.hikari.HikariJNDIFactory as my data source factory.
final Context context = new InitialContext();
HikariConfig hikariConfig = new HikariConfig();
hikariConfig.setDataSource((DataSource) ((Context)context.lookup("java:comp/env")).lookup("jdbc/mydb"));
HikariPool hikariPool = new HikariPool(hikariConfig);
LOGGER.log(Level.INFO, "The count is ::" + hikariPool.getActiveConnections());
But it is throwing the following exception:
java.lang.RuntimeException: java.lang.NullPointerException
at com.zaxxer.hikari.util.PoolUtilities.createInstance(PoolUtilities.java:105)
at com.zaxxer.hikari.metrics.MetricsFactory.createMetricsTracker(MetricsFactory.java:34)
at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:131)
at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:99)
at com.something.servlet.HikariConnectionCount.doGet(HikariConnectionCount.java:35)
Where HikariConnectionCount.java is the file I have written
Programatic access is documented here https://github.com/brettwooldridge/HikariCP/wiki/MBean-(JMX)-Monitoring-and-Management
Here's a dirty recipe:
import org.springframework.beans.DirectFieldAccessor;
import com.zaxxer.hikari.HikariDataSource;
import com.zaxxer.hikari.pool.HikariPool;
public class HikariDataSourcePoolDetail {
private final HikariDataSource dataSource;
public HikariDataSourcePoolDetail(HikariDataSource dataSource) {
this.dataSource = dataSource;
}
public HikariPool getHikariPool() {
return (HikariPool) new DirectFieldAccessor(dataSource).getPropertyValue("pool");
}
public int getActive() {
try {
return getHikariPool().getActiveConnections();
} catch (Exception ex) {
return -1;
}
}
public int getMax() {
return dataSource.getMaximumPoolSize();
}
}
Use it thus:
try {
HikariDataSourcePoolDetail dsd = new HikariDataSourcePoolDetail((HikariDataSource)dataSource);
log.info("HikariDataSource details: max={} active={}", dsd.getMax(), dsd.getActive());
} catch (Exception e) {
log.error("HikariDataSourcePoolDetail failed: ", e);
}
I am creating javafx application where I have this case that I need to listen for data sent over Bluetooth.
I have one fxml window on which I need to initialize Bluetooth and start listening from data.
Following is my Code for fxml controller:
//all imports
public class NewBarcodeInvoicePaneController implements Initializable{
private BluetoothController bc;
public BluetoothController getBc() {
return bc;
}
#Override
public void initialize(URL location, ResourceBundle resources) {
try {
bc = new BluetoothController();
new Thread(bc).start();
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
And BluetoothController is task where I initialize bluettoth and listen to the data
public class BluetoothController extends Task<Void> {
#Override
protected Void call() throws Exception {
LocalDevice local = null;
StreamConnectionNotifier notifier;
StreamConnection connection = null;
// setup the server to listen for connection
try {
local = LocalDevice.getLocalDevice();
try {
local.setDiscoverable(DiscoveryAgent.GIAC);
} catch (BluetoothStateException e) {
}
UUID uuid = new UUID(80087355); // "04c6093b-0000-1000-8000-00805f9b34fb"
String url = "btspp://localhost:" + uuid.toString() + ";name=RemoteBluetooth";
notifier = (StreamConnectionNotifier) Connector.open(url);
} catch (Exception e) {
e.printStackTrace();
return null;
}
try {
System.err.println("THIS IS HAPENING");
connection = notifier.acceptAndOpen();
System.err.println("HAPENING???????????????????????????");
InputStream inputStream = connection.openInputStream();
BufferedReader bReader = new BufferedReader(new InputStreamReader(inputStream));
String lineRead = bReader.readLine();
connection.close();
inputStream.close();
notifier.close();
local.setDiscoverable(DiscoveryAgent.NOT_DISCOVERABLE);
JSONParser parser = new JSONParser();
Object obj = parser.parse(lineRead);
JSONArray array = (JSONArray) obj;
array.stream().map((o) -> (String) o).forEach((stringObj) -> {
System.out.println(stringObj);
});
System.out.println("AFTER DATA RECIEVED");
} catch (Exception e) {
e.printStackTrace();
return null;
}
return null;
}
}
It Works fine if I send data over bluetooth and blocking call to notifier.acceptAndOpen() is unblocked.
My problem is when we do not pass any data and I just want to close the window I opened..
It still have blocking call open with extra thread by the task.
I tried to cancel BluetoothController task in Main controller where I open this window like following
private void openNewBarcodeInvoicePane(ActionEvent ae) {
//following are custom classes to open windows from fxml and getting controller back for further manipulation
PostoryModalWindow modalWindow = new PostoryModalWindow();
modalWindow.openNewModalPaneWithParent("New Invoice", "fxml/newbarcodeinvoicepane.fxml", ae);
//getting controller object
NewBarcodeInvoicePaneController controller = (NewBarcodeInvoicePaneController) modalWindow.getDswFromController();
controller.getWindowStage().showAndWait();
BluetoothController bc = controller.getBc();
if(bc != null){
System.err.println("CANCELLING");
bc.cancel(true);
}
}
But it doesn't throw InterrupttedExeption (In which I might have Choice to close Bluetooth thread) and after research I found that waiting on Socket doesn't work on interrupt.
Any help on this?
Thanks
Got Solution After Some Research.
I just added new task to call notifier.acceptAndOpen();
And added method to close Bluetooth notifier.
public class BluetoothController extends Task<Void> {
private final ObservableList<Item> items = FXCollections.observableArrayList();
public ObservableList<Item> getItems() {
return items;
}
StreamConnectionNotifier notifier;
#Override
protected Void call() throws Exception {
try {
BluetoothConnectionTask bct = new BluetoothConnectionTask(items);
new Thread(bct).start();
Thread.sleep(2000);
notifier = bct.getNotifier();
} catch (Exception e) {
e.printStackTrace();
return null;
}
return null;
}
public void cancelandExit() {
try {
if (notifier != null) {
notifier.close();
}
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
Here is new task for blocking call
public class BluetoothConnectionTask extends Task<Void>{
private StreamConnectionNotifier notifier;
private StreamConnection connection;
private ObservableList<Item> items = FXCollections.observableArrayList();
public StreamConnection getConnection() {
return connection;
}
public StreamConnectionNotifier getNotifier() {
return notifier;
}
public BluetoothConnectionTask(ObservableList<Item> is){
items = is;
}
#Override
protected Void call() throws Exception {
try {
LocalDevice local = LocalDevice.getLocalDevice();
try {
local.setDiscoverable(DiscoveryAgent.GIAC);
} catch (BluetoothStateException e) {
}
UUID uuid = new UUID(80087355); // "04c6093b-0000-1000-8000-00805f9b34fb"
String url = "btspp://localhost:" + uuid.toString() + ";name=RemoteBluetooth";
notifier = (StreamConnectionNotifier) Connector.open(url);
} catch (Exception e) {
e.printStackTrace();
return null;
}
connection = notifier.acceptAndOpen();
InputStream inputStream = connection.openInputStream();
BufferedReader bReader = new BufferedReader(new InputStreamReader(inputStream));
String lineRead = bReader.readLine();
connection.close();
inputStream.close();
notifier.close();
LocalDevice local = LocalDevice.getLocalDevice();
local.setDiscoverable(DiscoveryAgent.NOT_DISCOVERABLE);
JSONParser parser = new JSONParser();
Object obj = parser.parse(lineRead);
JSONArray array = (JSONArray) obj;
ItemDAO idao = new ItemDAO();
array.stream().map((o) -> (String) o).forEach((stringObj) -> {
String barcode = (String) stringObj;
Item i = idao.getItemByBarCode(barcode);
System.err.println("Adding Item "+i.getName());
items.add(i);
});
System.out.println("AFTER DATA RECIEVED");
return null;
}
}
Now for cancelling closing my bluetooth thread I am calling cancelandExit() after window is closed.
This is the error which arises when I tried to debug an application under Visual C# 2010
I write that code to retrieve some rows from a database table, I already attached the two well known databases Pubs and Northwind to the db explorer, but the error remains
class Author
{
SqlConnection _pubConnection;
string _connString;
public Author()
{
_connString = "Data Source=./INSTANCE2;Initial Catalog=pubs;Integrated Security=True";
_pubConnection = new SqlConnection();
_pubConnection.ConnectionString = _connString;
}
public int CountAuthors()
{
try
{
SqlCommand pubCommand = new SqlCommand();
pubCommand.Connection = _pubConnection;
pubCommand.CommandText = "Select Count(au_id) from authors";
_pubConnection.Open();
return (int)pubCommand.ExecuteScalar();
}
catch (SqlException ex)
{
throw ex;
}
finally
{
if (_pubConnection != null)
{
_pubConnection.Close();
}
}
}
}
static void Main(string[] args)
{
try
{
Author author = new Author();
Console.WriteLine(author.CountAuthors());
Console.ReadLine();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
Console.ReadLine();
}
}
the Connection string isn't ok , i correct it and it works fine
I am getting the following error message:
System.InvalidOperationException: ExecuteReader requires an open and available Connection. The connection's current state is Closed.
And here is my code:
public IDataReader ExecuteReader()
{
IDataReader reader = null;
try
{
this.Open();
reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
}
catch (Exception ex)
{
if (handleErrors)
strLastError = ex.Message;
else
throw;
}
catch
{
throw;
}
return reader;
}
Does anyone know how I can resolve this?
The Connection object that your SQLCommand is attached to has not been opened. You must open the connection before you can query.
Something like this:
private static void OpenSqlConnection(string connectionString)
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
var cmd = connection.CreateCommand();
// Do your command access here.
}
}