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NullPointerException while connecting to Mqtt on-line broker

I'm trying to connect to the on-line broker https://test.mosquitto.org/ using the code below and the Paho library in Java:
private final String brokerURI = "test.mosquitto.org:1883"; //should be changed to 8883 with SSL
try { //tentativo di creazione del client
client = new MqttClient(brokerURI, idClient); <--NullPointerException here
client.setCallback(new ClientCallback(codaTopic, codaMessaggi, finestra)); //set delle callback
setConnectionOptions(); //set delle opzioni connessione
client.connect(opzioni); //connessione al server
} catch (MqttException e) {
System.err.println(e.getMessage());
System.err.println("Connessione fallita Client, riavviare il sistema.");
}
Connection options are set here:
private void setConnectionOptions() {
opzioni = new MqttConnectOptions();
opzioni.setAutomaticReconnect(true);
opzioni.setCleanSession(false);
opzioni.setConnectionTimeout(30);
opzioni.setKeepAliveInterval(60);
}
but it continues to show a NullPointerException while creating the MqttClient. In particular the console displays:
Exception in thread "Thread-3" java.lang.NullPointerException
at org.eclipse.paho.client.mqttv3.MqttConnectOptions.validateURI(MqttConnectOptions.java:489)
at org.eclipse.paho.client.mqttv3.MqttAsyncClient.<init>(MqttAsyncClient.java:291)
at org.eclipse.paho.client.mqttv3.MqttAsyncClient.<init>(MqttAsyncClient.java:185)
at org.eclipse.paho.client.mqttv3.MqttClient.<init>(MqttClient.java:226)
at org.eclipse.paho.client.mqttv3.MqttClient.<init>(MqttClient.java:138)
at client.Client.run(Client.java:78)
How can i manage to connect and use SSL?
Surfing the net none of the tutorial or guides were useful, I already downloaded the mosquitto.org.crtfile for SSL connection, but i don't know where to use it and I found no tutorials.
EDIT
Changing the BrokerUri to
private final String brokerURI = "tcp://test.mosquitto.org:1883"; //indirizzo broker
the console shows the error
Client non connesso (32104)
at org.eclipse.paho.client.mqttv3.internal.ExceptionHelper.createMqttException(ExceptionHelper.java:31)
at org.eclipse.paho.client.mqttv3.internal.ClientComms.sendNoWait(ClientComms.java:166)
at org.eclipse.paho.client.mqttv3.MqttAsyncClient.subscribe(MqttAsyncClient.java:835)
at org.eclipse.paho.client.mqttv3.MqttClient.subscribe(MqttClient.java:322)
at org.eclipse.paho.client.mqttv3.MqttClient.subscribe(MqttClient.java:315)
at client.Client.subscribe(Client.java:214)
at client.Client.run(Client.java:89)
while trying to subscribe to a Topic with the instruction
client.subscribe(topic, 1);
The topic argument is a String that contains the topic name.

Mosquitto's URI needs the protocol. Taking a look at its source code, this is where your exception is being thrown, class MqttConnectOpts.java :
protected static int validateURI(String srvURI) {
try {
URI vURI = new URI(srvURI);
if (!vURI.getPath().equals("")) {
throw new IllegalArgumentException(srvURI);
}
if (vURI.getScheme().equals("tcp")) {
return URI_TYPE_TCP;
}
else if (vURI.getScheme().equals("ssl")) {
return URI_TYPE_SSL;
}
else if (vURI.getScheme().equals("local")) {
return URI_TYPE_LOCAL;
}
else {
throw new IllegalArgumentException(srvURI);
}
} catch (URISyntaxException ex) {
throw new IllegalArgumentException(srvURI);
}
}
So, it accepts 3 types of protocol prefixes: tcp, ssl, local. Regarding your example, you could try it this way:
TCP
private final String brokerURI = "tcp://test.mosquitto.org:1883";
SSL
private final String brokerURI = "ssl://test.mosquitto.org:8883";

Timeout while receiving message with Mongo Connection pooling using java

In production we are connecting with a MongoDB using Java (connection pooling). Every day we are getting almost 500 requests with the error below (MongoSocketReadTimeoutException) and we are not using any complex query. Could it be stale Mongo connections?
I didn't see a problem with our code or MongoDB slowness. Please review my code below and suggest if any parameters need to be added or anything needs to be changed.
at 2018-03-07 19:52:43 ERROR ::Error while connecting the Mongo DB {}
com.mongodb.MongoSocketReadTimeoutException: Timeout while receiving message
at com.mongodb.connection.InternalStreamConnection.translateReadException(InternalStreamConnection.java:474)
at com.mongodb.connection.InternalStreamConnection.receiveMessage(InternalStreamConnection.java:225)
at com.mongodb.connection.UsageTrackingInternalConnection.receiveMessage(UsageTrackingInternalConnection.java:102)
at com.mongodb.connection.DefaultConnectionPool$PooledConnection.receiveMessage(DefaultConnectionPool.java:435)
at com.mongodb.connection.CommandProtocol.execute(CommandProtocol.java:112)
at com.mongodb.connection.DefaultServer$DefaultServerProtocolExecutor.execute(DefaultServer.java:159)
at com.mongodb.connection.DefaultServerConnection.executeProtocol(DefaultServerConnection.java:286)
at com.mongodb.connection.DefaultServerConnection.command(DefaultServerConnection.java:173)
at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:215)
at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:206)
at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:112)
at com.mongodb.operation.FindOperation$1.call(FindOperation.java:487)
at com.mongodb.operation.FindOperation$1.call(FindOperation.java:482)
at com.mongodb.operation.OperationHelper.withConnectionSource(OperationHelper.java:239)
at com.mongodb.operation.OperationHelper.withConnection(OperationHelper.java:212)
at com.mongodb.operation.FindOperation.execute(FindOperation.java:482)
at com.mongodb.operation.FindOperation.execute(FindOperation.java:79)
at com.mongodb.Mongo.execute(Mongo.java:772)
at com.mongodb.Mongo$2.execute(Mongo.java:759)
at com.mongodb.FindIterableImpl$FindOperationIterable.first(FindIterableImpl.java:207)
at com.mongodb.FindIterableImpl.first(FindIterableImpl.java:148)
at com.tecnotree.bom.validation.dao.MongoManager.getJsonObject(MongoManager.java:88)
at com.tecnotree.bom.validation.dao.CustomerMasterDao.getService(CustomerMasterDao.java:48)
at com.tecnotree.bom.validation.service.ValidationService.processValidation(ValidationService.java:214)
at com.tecnotree.bom.validation.service.ValidationService.processRequest(ValidationService.java:125)
at sun.reflect.GeneratedMethodAccessor185.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.sun.jersey.spi.container.JavaMethodInvokerFactory$1.invoke(JavaMethodInvokerFactory.java:60)
at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvid
er.java:205)
Code
public class ConnectionManager {
private ConnectionManager() {
}
private static final Logger logger = LoggerFactory.getLogger(ConnectionManager.class);
private static MongoClient mongoClient = null;
private static String connections = null;
private static String connectionTimeOut = null;
private static String socketTimeOut = null;
private static String serverSelectionTimeOut = null;
private static String URL = null;
private static String username = null;
private static String password = null;
private static String hostname = null;
private static String port = null;
private static String maxConnectionIdleTime = null;
private static String minConnectionsPerHost = null;
private static String maxConnectionLifeTime = null;
private static String dbName = null;
static {
dbName = ValidationProperties.getValue("clm.db.dbName");
mongoClient = getCLMSecondaryMongoConnection();
}
private static MongoClient getCLMSecondaryMongoConnection() {
connections = ValidationProperties.getValue("clm.db.connectionsPerHost");
connectionTimeOut = ValidationProperties.getValue("clm.db.connectTimeoutMS");
socketTimeOut = ValidationProperties.getValue("clm.db.socketTimeOut");
serverSelectionTimeOut = ValidationProperties.getValue("clm.db.serverSelectionTimeOut");
username = ValidationProperties.getValue("clm.db.userName");
password = ValidationProperties.getValue("clm.db.password");
hostname = ValidationProperties.getValue("clm.db.hostname");
port = ValidationProperties.getValue("clm.db.portnumber");
maxConnectionIdleTime = ValidationProperties.getValue("clm.db.maxConnectionIdleTime");
minConnectionsPerHost = ValidationProperties.getValue("clm.db.minConnectionsPerHost");
try {
List<MongoCredential> creds = new ArrayList<MongoCredential>();
creds.add(MongoCredential.createCredential(username, dbName, password.toCharArray()));
/*creds.add(MongoCredential.createMongoCRCredential(username, dbName, password.toCharArray()));*/
MongoClientOptions.Builder optionsBuilder = MongoClientOptions.builder();
optionsBuilder.connectTimeout(Integer.parseInt(connectionTimeOut));
optionsBuilder.serverSelectionTimeout(Integer.parseInt(serverSelectionTimeOut));
optionsBuilder.socketTimeout(Integer.parseInt(socketTimeOut));
optionsBuilder.connectionsPerHost(Integer.parseInt(connections));
optionsBuilder.maxConnectionIdleTime(Integer.parseInt(maxConnectionIdleTime));
optionsBuilder.minConnectionsPerHost(Integer.parseInt(minConnectionsPerHost));
if(Boolean.valueOf(ValidationProperties.getValue("clm.db.useSecondaryMongoForRead"))) {
logger.info("Read is going for secondary mongoDB");
optionsBuilder.readPreference(ReadPreference.secondaryPreferred());
}
MongoClientOptions options = optionsBuilder.build();
mongoClient = new MongoClient(new ServerAddress(hostname, Integer.parseInt(port)), creds, options);
} catch (Exception e) {
logger.error("Error while connecting the Mongo DB {}", e);
}
return mongoClient;
}
public static MongoClient getMongoClient() {
return mongoClient;
}

In your code you are setting various MongoClientOptions, but you do not say what values you are using. Most likely one of the settings is causing the problem. My first guess would be that socketTimeout is too small, my second guess would be that connectionsPerHost is smaller than the maximum number of concurrent requests you receive in production.
I assume that testing in your production environment is not an option, so the first thing you should do is try and reproduce the problem in a test environment. You can use the free JMeter tool to reproduce a certain load to your server. Use it's ramp-up feature to see if your problems start once you reach a certain load or if they occur at random.
If you still have trouble finding out what exactly causes the problems, you can also try to comment out all your optionBuilder settings (so you'll be using all default settings). If that fixes the problem, then you can set back your configuration options one-at-a-time to see which is the problematic one.

You must remove hibernate dependency from your project.
I faced this problem and that was the solution.

java.net.Authenticator : java.net.ProtocolException: Server redirected too many times (20)

We are calling URL using proxy settings via java standalone sample code on our weblogic servers (node1/node2).
This code works fine on node 1 but same code doesn't work on node2 server.
We already checked proxy settings and credentials all are fine but still we get following error :
java.net.ProtocolException: Server redirected too many times (20)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1323)
at ProxyCode.start2(ProxyCode.java:54)
at ProxyCode.main(ProxyCode.java:23)
Exception in thread "Main Thread" java.lang.NullPointerException
at java.io.Reader.<init>(Reader.java:61)
at java.io.InputStreamReader.<init>(InputStreamReader.java:55)
at ProxyCode.readFromInputStream(ProxyCode.java:65)
at ProxyCode.start2(ProxyCode.java:59)
at ProxyCode.main(ProxyCode.java:22)
Also , Please find my code snippet below :
SimpleAuthenticator.java
import java.net.Authenticator;
import java.net.PasswordAuthentication;
public class SimpleAuthenticator extends Authenticator
{
private String username;
private String password;
public SimpleAuthenticator(String username,String password)
{
this.username = username;
this.password = password;
}
protected PasswordAuthentication getPasswordAuthentication()
{
return new PasswordAuthentication(
username,password.toCharArray());
}
}
Main class :
String url = "http://www.oracle.com/technetwork/java/readme-2-149793.txt";
String proxy = "proxyserver";
String port = "8080";
String username = "username";
String password = "password";
Authenticator.setDefault(new SimpleAuthenticator(username,password));
URL server = null;
try {
CookieHandler.setDefault(new CookieManager(null, CookiePolicy.ACCEPT_ALL));
server = new URL(url);
}
catch (MalformedURLException e) {
e.printStackTrace();
}
Properties systemProperties = System.getProperties();
systemProperties.setProperty("http.proxyHost", proxy);
systemProperties.setProperty("http.proxyPort", port);
InputStream in = null;
URLConnection connection = null;
try {
connection = (URLConnection) server.openConnection();
connection.connect();
in = connection.getInputStream();
}
catch (IOException e) {
e.printStackTrace();
}
System.out.println(readFromInputStream(in));
}
public static String readFromInputStream(InputStream in) {
StringBuffer strBuf = new StringBuffer();
char ac[];
BufferedReader buf = new BufferedReader(new InputStreamReader(in));
try
{
while (buf.ready()) {
ac = new char[10000];
buf.read(ac);
strBuf.append(ac);
}
buf.close();
}
catch (IOException e) {
e.printStackTrace();
}
We are stuck in this since months now and not able to get any useful information anywhere.
kindly help.thanks

You will get this error if you provide wrong credentials (username or password).
This happened to me with a Glassfish based web app. I was expecting a 401 response however.
I think, the Authenticator tries the same credentials many times.

Found this open issue, still unfixed it would seem. Your user doesn't have access rights, but instead of prompting again it retries with the same user over and over
Update: The issue had another ticket open - this is apparently expected behaviour and
"To overcome this, your implementation of
Authenticator::getPasswordAuthentication needs to provide a means to
collect the correct password if the initial authentication attempt was
not successful."
See the ticket or the java.net.Authenticator documentation for more info.

When to disconnect bosh connection establish from app server to use prebinding in strophe?

This question is Extension of my previous question on this SO question "How to connect XMPP bosh server using java smack library?"
I am using Java as server side language. I have successfully implement xmpp BOSH connection using smach-jbosh thanks to #Deuteu for helping me to achieve this, so far I have modify jbosh's BOSHClient.java file and added two getter method for extracting RID and SID.
Now I have RID and SID on my app server (I am using Apache Tomcat). I need to pass this credential to Strophe (web client) so that it can attach to connection.
Here I have some doubt.
When to disconnect bosh Connection establish from the app server? before passing sid, rid and jid to strophe or after passing sid, rid and jid to strophe?
As per my observation during implementation for the same, I have observed that once bosh connection from the app server has been disconnected, session is expired and SID and RID is no longer useful!!!
I have implemented this logic (Establishing bosh connection and Extracting sid and rid) on a Servlet, here once response has been send from Servlet, Thread will get expired and end BOSH connection will get terminated, so I am not able perform `Attach()` on strophe as session is expired.
Can somebody help me with that problem?

I believe #fpsColton's answer is correct - I'm just added extra info for clarity. As requested on linked thread here is the code changes I made on this - note: I only added the parts where I've labelled "DH"
In BOSHConnection:
// DH: function to preserve current api
public void login(String username, String password, String resource)
throws XMPPException {
login(username, password, resource, false);
}
// DH: Most of this is existing login function, but added prebind parameter
// to allow leaving function after all required pre-bind steps done and before
// presence stanza gets sent (sent from attach in XMPP client)
public void login(String username, String password, String resource, boolean preBind)
throws XMPPException {
if (!isConnected()) {
throw new IllegalStateException("Not connected to server.");
}
if (authenticated) {
throw new IllegalStateException("Already logged in to server.");
}
// Do partial version of nameprep on the username.
username = username.toLowerCase().trim();
String response;
if (config.isSASLAuthenticationEnabled()
&& saslAuthentication.hasNonAnonymousAuthentication()) {
// Authenticate using SASL
if (password != null) {
response = saslAuthentication.authenticate(username, password, resource);
} else {
response = saslAuthentication.authenticate(username, resource, config.getCallbackHandler());
}
} else {
// Authenticate using Non-SASL
response = new NonSASLAuthentication(this).authenticate(username, password, resource);
}
// Indicate that we're now authenticated.
authenticated = true;
anonymous = false;
// DH: Prebind only requires connect and authenticate
if (preBind) {
return;
}
// Set the user.
if (response != null) {
this.user = response;
// Update the serviceName with the one returned by the server
config.setServiceName(StringUtils.parseServer(response));
} else {
this.user = username + "#" + getServiceName();
if (resource != null) {
this.user += "/" + resource;
}
}
// Create the roster if it is not a reconnection.
if (this.roster == null) {
this.roster = new Roster(this);
}
if (config.isRosterLoadedAtLogin()) {
this.roster.reload();
}
// Set presence to online.
if (config.isSendPresence()) {
sendPacket(new Presence(Presence.Type.available));
}
// Stores the autentication for future reconnection
config.setLoginInfo(username, password, resource);
// If debugging is enabled, change the the debug window title to include
// the
// name we are now logged-in as.l
if (config.isDebuggerEnabled() && debugger != null) {
debugger.userHasLogged(user);
}
}
and
// DH
#Override
public void disconnect() {
client.close();
}
then my Client-side (Web Server) wrapper class - for connecting from within JSP is:
Note: This is proving code rather than production - so there's some stuff in here you may not want.
public class SmackBoshConnector {
private String sessionID = null;
private String authID = null;
private Long requestID = 0L;
private String packetID = null;
private boolean connected = false;
public boolean connect(String userName, String password, String host, int port, final String xmppService) {
boolean success = false;
try {
Enumeration<SaslClientFactory> saslFacts = Sasl.getSaslClientFactories();
if (!saslFacts.hasMoreElements()) {
System.out.println("Sasl Provider not pre-loaded");
int added = Security.addProvider(new com.sun.security.sasl.Provider());
if (added == -1) {
System.out.println("Sasl Provider could not be loaded");
System.exit(added);
}
else {
System.out.println("Sasl Provider added");
}
}
BOSHConfiguration config = new BOSHConfiguration(false, host, port, "/http-bind/", xmppService);
BOSHConnection connection = new BOSHConnection(config);
PacketListener sndListener = new PacketListener() {
#Override
public void processPacket(Packet packet) {
SmackBoshConnector.this.packetID = packet.getPacketID();
System.out.println("Send PacketId["+packetID+"] to["+packet.toXML()+"]");
}
};
PacketListener rcvListener = new PacketListener() {
#Override
public void processPacket(Packet packet) {
SmackBoshConnector.this.packetID = packet.getPacketID();
System.out.println("Rcvd PacketId["+packetID+"] to["+packet.toXML()+"]");
}
};
PacketFilter packetFilter = new PacketFilter() {
#Override
public boolean accept(Packet packet) {
return true;
}
};
connection.addPacketSendingListener(sndListener, packetFilter);
connection.addPacketListener(rcvListener, packetFilter);
connection.connect();
// login with pre-bind only
connection.login(userName, password, "", true);
authID = connection.getConnectionID();
BOSHClient client = connection.getClient();
sessionID = client.getSid();
requestID = client.getRid();
System.out.println("Connected ["+authID+"] sid["+sessionID+"] rid["+requestID+"]");
success = true;
connected = true;
try {
Thread.yield();
Thread.sleep(500);
}
catch (InterruptedException e) {
// Ignore
}
finally {
connection.disconnect();
}
} catch (XMPPException ex) {
Logger.getLogger(SmackBoshConnector.class.getName()).log(Level.SEVERE, null, ex);
}
return success;
}
public boolean isConnected() {
return connected;
}
public String getSessionID() {
return sessionID;
}
public String getAuthID() {
return authID;
}
public String getRequestIDAsString() {
return Long.toString(requestID);
}
public String getNextRequestIDAsString() {
return Long.toString(requestID+1);
}
public static void main(String[] args) {
SmackBoshConnector bc = new SmackBoshConnector();
bc.connect("dazed", "i3ji44mj7k2qt14djct0t5o709", "192.168.2.15", 5280, "my.xmppservice.com");
}
}
I confess that I'm don't fully remember why I put the Thread.yield and Thread.sleep(1/2 sec) in here - I think - as you can see with added PacketListener - the lower level functions return after sending data and before getting a response back from the server - and if you disconnect before the server has sent it's response then it (also) causes it to clean up the session and things won't work. However it may be that, as #fpsColton says, this dicsonnect() isn't actually required.
Edit: I now remember a bit more about whay I included sleep() and yield(). I noticed that Smack library includes sleep() in several places, including XMPPConnection.shutdown() as per source. Plus in terms of yield() I had problems in my environment (Java in Oracle Database - probably untypical) when it wasn't included - as per Smack Forum Thread.
Good luck.

After you have created a BOSH session with smack and have extracted the SID+RID values, you need to pass them to Strophe's attach() and from here on out you need to let strophe deal with this connection. Once Strophe has attached, you do not want your server to be doing anything to the connection at all.
If your server side code sends any messages at all to the connection manager after strophe has attached, it's likely that it will send a invalid RID which will cause your session to terminate.
Again, once the session has been established and is usable by strophe, do not attempt to continue using it from the server side. After your server side bosh client completes authentication and you've passed the SID+RID to the page, just destroy the server side connection object, don't attempt to disconnect or anything as this will end your session.
The thing you need to remember is, unlike traditional XMPP connections over TCP, BOSH clients do NOT maintain a persistent connection to the server (this is why we use BOSH in web applications). So there is nothing to disconnect. The persistent connection is actually between the XMPP server and the BOSH connection manager, it's not something you need to deal with. So when you call disconnect from your server side BOSH client, you're telling the connection manager to end the session and close it's connection to the XMPP server, which completely defeats the purpose of creating the session in the first place.

Connecting to SSL WebService

I want to connect to a web service in a SSL connection. I connect to it and I get Service and Port but when I send Requests, it just returns null.
I searched the web but I could not understand what is the problem. may be because it is SSL, I need to connect it different as an Http connection, is it true?
I used auto code generators, they return null too, WireShark says that SSL Packages transmitted correctly but I cannot read the SOAP from these packages because they are SSL.
I test the web service with some applications and the tools and got correct answers from them.
Question:
is it possible that the null value is because SSL connection?
what mistakes could make this null returning?
How can I see the SOAP messeges I send and I get?
Here is My Java Code:
public class WS_TheServeice
{
private static QName qname;
private static URL url;
private static Service service;
private static ImplementationServicePortType sender;
static
{
qname = new QName("http://wservice.com/", "ImplementationService");
try
{
url = new URL("https://to-service?wsdl");
}
catch (MalformedURLException e)
{
e.printStackTrace();
}
service = Service.create(url, qname);
sender = service.getPort(ImplementationServicePortType.class);
}
public static boolean PayToAcceptor(int AcceptorID, int Kipa) throws Exception
{
getUserInfo req = new getUserInfo();
req.zpID = AcceptorID;
req.kipa = Kipa;
getUserInfoResponse user_info = new getUserInfoResponse();//user_info is not NULL here
user_info = sender.getUserInfo(req);//But web server makes it NULL
if (user_info!=null) //// ---- HERE, IT Always return NULL
{
System.out.println("YouWon");
return true;
}
else
{
System.out.println("YouLoose");
return false;
}
}
public static void main(String Args[]) throws Exception
{
PayToAcceptor(12345, 1);
}
}
thanks.

Did you figure out how to do this? I've had similar problems in the past..
Did you try this: SSL Connection for consuming web services ?