I'm running the following code:
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
public class RmiClient {
public static void main(String args[]) {
try {
String hostName = "hostnameChangedForOnlineReference";
Registry registry = LocateRegistry.getRegistry(hostName, 1099);
String[] names = registry.list();
for (String name : names) {
System.out.println(name);
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
And getting the following error
java.rmi.ConnectIOException: non-JRMP server at remote endpoint
at sun.rmi.transport.tcp.TCPChannel.createConnection(TCPChannel.java:230)
at sun.rmi.transport.tcp.TCPChannel.newConnection(TCPChannel.java:184)
at sun.rmi.server.UnicastRef.newCall(UnicastRef.java:322)
at sun.rmi.registry.RegistryImpl_Stub.list(Unknown Source)
at RmiClient.main(RmiClient.java:9)
Yet other RMI code running on my machine connects to this same service just fine.
Can anyone suggest a path of investigation for this inconsistent behaviour on my machine?
(When I do rmi in spring I get exactly the same error, but this is an easier set of code to digest).
non-JRMP server at remote endpoint
means that it turns out turning on SSL was required.
Related
Library in use:
AsyncHtpClient Library:
Version : 1.9.32
Location: https://github.com/AsyncHttpClient/async-http-client
Netty Version : 3.10.3.Final
Proxy: Squid Proxy
I am trying to create a websocket connection using AsyncHttpClinet library. It works fine when using without the proxy.
But when I start a proxy and pass in the Host, port, username and password , I am unable to create a websocket connection.
It get a stack trace which says Invalid Status Code 400:
Caused by: java.lang.IllegalStateException: Invalid Status Code 400
at com.ning.http.client.ws.WebSocketUpgradeHandler.onCompleted(WebSocketUpgradeHandler.java:76)
at com.ning.http.client.ws.WebSocketUpgradeHandler.onCompleted(WebSocketUpgradeHandler.java:29)
at com.ning.http.client.providers.netty.future.NettyResponseFuture.getContent(NettyResponseFuture.java:177)
at com.ning.http.client.providers.netty.future.NettyResponseFuture.done(NettyResponseFuture.java:214)
... 35 more
I am setting the proxy object like this:
ProxyServer ps = new ProxyServer("host-name",portNo,"user_name","password");
AsyncHttpClientConfig cf = new AsyncHttpClientConfig.Builder().setProxyServer(ps).build();
WebSocket websocket = c.prepareGet(url)
.execute(new WebSocketUpgradeHandler.Builder().addWebSocketListener(
new WebSocketTextListener() {
#Override
public void onMessage(String message) {
}
#Override
public void onFragment(String s, boolean b) {
}
#Override
public void onOpen(WebSocket websocket) {
}
#Override
public void onClose(WebSocket websocket) {
}
#Override
public void onError(Throwable t) {
}
}
).build()
).get();
Are there any other steps to configure a proxy for websocket connections?
I have also tried configuring the ProxyServer object like this:
ProxyServer ps = new ProxyServer(ProxyServer.Protocol.HTTPS,"host-name",portNo,"user_name","password");
I am using Spring Cloud AWS (1.0.1.RELEASE) with Spring Boot to run a SQS consumer. The application runs fine, but when it looses network connection (for instance if I switch my WIFI off on my laptop when it runs on it), I see errors on the console and the application never recovers. It just hangs there and does not reconnect after the network becomes available. I have to kill it and bring it up. How do I force it to recover by itself?
// Spring Boot entry point:
public static void main(String[] args) {
SpringApplication.run(MyConsumerConfiguration.class, args);
}
// Message Listener (A different class)
#MessageMapping(value = "myLogicalQueueName" )
public void receive(MyPOJO object) {
}
The error I see at console:
Exception in thread "simpleMessageListenerContainer-1" com.amazonaws.AmazonClientException: Unable to execute HTTP request: sqs.us-east-1.amazonaws.com
at com.amazonaws.http.AmazonHttpClient.executeHelper(AmazonHttpClient.java:473)
at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:297)
at com.amazonaws.services.sqs.AmazonSQSClient.invoke(AmazonSQSClient.java:2422)
at com.amazonaws.services.sqs.AmazonSQSClient.receiveMessage(AmazonSQSClient.java:1130)
at com.amazonaws.services.sqs.AmazonSQSAsyncClient$23.call(AmazonSQSAsyncClient.java:1678)
at com.amazonaws.services.sqs.AmazonSQSAsyncClient$23.call(AmazonSQSAsyncClient.java:1676)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745
I just figured out the problem why SQS is not able to reconnect after network connection lost.
Actually seems to be a problem in current Spring AWS implementation of org.springframework.cloud.aws.messaging.listener.SimpleMessageListenerContainer.java
private class AsynchronousMessageListener implements Runnable {
private final QueueAttributes queueAttributes;
private final String logicalQueueName;
private AsynchronousMessageListener(String logicalQueueName, QueueAttributes queueAttributes) {
this.logicalQueueName = logicalQueueName;
this.queueAttributes = queueAttributes;
}
#Override
public void run() {
while (isRunning()) {
ReceiveMessageResult receiveMessageResult = getAmazonSqs().receiveMessage(this.queueAttributes.getReceiveMessageRequest());
CountDownLatch messageBatchLatch = new CountDownLatch(receiveMessageResult.getMessages().size());
for (Message message : receiveMessageResult.getMessages()) {
if (isRunning()) {
MessageExecutor messageExecutor = new MessageExecutor(this.logicalQueueName, message, this.queueAttributes);
getTaskExecutor().execute(new SignalExecutingRunnable(messageBatchLatch, messageExecutor));
} else {
break;
}
}
try {
messageBatchLatch.await();
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
}
}
}
}
Above code spins up a new thread which does the polling to SQS queue to grab messages. Once network connection is dropped getAmazonSqs().receiveMessage(this.queueAttributes.getReceiveMessageRequest()) throws UnknownHostException, which is not handled in the code and causes thread termination.
So when network connection is established later on, there is no thread polling the queue to retrieve the data.
I have already raised a issue with Spring for this. Following is the link: https://github.com/spring-cloud/spring-cloud-aws/issues/82
Hope this explains it all.
i have a strange problem. I developed client-server application with Java RMI, and in the localhost work very fine, also work very well if i put the client and server on two different MacBook Pro, but work very very slowly if i try to put the client and the server on two computer that are not macbook pro. I have this problem only if i try to send a reference of the client to the server with invocation of a remote method.
This is my code
SERVER:
public class Server{
public static void main(String [] args){
try
{
Server_Impl server=new Server_Impl();
Registry reg=LocateRegistry.createRegistry(1099);
reg.bind("Server",server);
if(new Scanner(System.in).nextInt()==-1){
System.exit(0);
}
}
catch (RemoteException e){e.printStackTrace( );}
catch (AlreadyBoundException e) {e.printStackTrace( );}
}
}
CLIENT
public class Client{
public static Interfaccia_Server Server;
public static void main(String [] args){
try{
Registry reg=LocateRegistry.getRegistry("10.0.1.5",1099);
Server = (Interfaccia_Server) reg.lookup("Server");
Client_Impl c= new Client_Impl(Server);
Server.connect_client(c);
c.check_action();
}
catch(Exception e){
}
}
}
All of the code work, but very very slow if client and server are not on the same machine, or on a apple mac computer.
If i remove this line of code from the client all work very well anywhere, but i need the reference of the client in the server
Server.connect_client(c);
I have no idea about, please help me
I am trying to manipulate an Apache Derby DB on NetBeans and I'm having a tough time connecting.
It seems very simple but it just wouldn't connect.
Please help. Thanks in advance!
import java.sql.*;
public class JDBCtutorial {
private static String tableName = "Diseases";
private static Connection conn = null;
private static Statement stmt = null;
public static void createConnection() {
try {
Class.forName("org.apache.derby.jdbc.ClientDriver");
} catch(ClassNotFoundException cnfe) {
System.out.println(cnfe);
}
try {
conn = DriverManager.getConnection("jdbc:derby://localhost:1527/DBName", "user", "password");
} catch (Exception e) {
System.out.println("Cannot connect. . .");
}
}
public static void main(String[] args) {
createConnection();
}
}
You're using the driver for embedded use of Derby (org.apache.derby.jdbc.EmbeddedDriver), yet you try to connect over the network, in which case you should use the network driver, org.apache.derby.jdbc.ClientDriver.
All this is explained in detail in the Derby doc which is quite good.
Also, as probably getConnection is throwing an exception that might give some hints about the cause of the problem, try pinting the stacktrace, it should provide that info:
} catch (Exception e) {
System.out.println("Cannot connect:");
e.printStackTrace();
}
You Just need to add one library file in your project.
Download here
Eclipse : Right Click on project then > Build Path > Configure Build Path > Add External JAR (and select the file you downloaded) > Done
NetBeans : Right Click on project then > Properties > Libraries > ADD JAR/Folder
"and select the file you downloaded " > ok (Run)
Add Permanently : Add the file in c:/program files/java/JRE/lib/ folder
I am new to JMS and have an issue connecting to a remote JMS queue from my standalone client. Any hints on resolving this issue would be highly appreciated.
Right now I have a JavaFX standalone application that runs on multiple clients and a glassfish server 3.1.2.2 running on a remote Unix machine. I am having a hard time pushing messages from my standalone app on to the queue that is residing on the server.
Client Mc: Windows PC (No server installed)
Remote Mc: Unix (GlassFish 3.1.2.2 installed)
JMS resources on the server:
JMS Destination Resource
JNDI Name: jms/ReferralQueue
Physical Destination Name: ReferralQueue
Resource Type: javax.jms.Queue
JMS Connection Factory
Pool Name: jms/ReferralConnectionFactory
JNDI Name: jms/ReferralConnectionFactory
Resource Type: javax.jms.QueueConnectionFactory
JMS Service Type: Embedded
JMS Message Store Type: File
Client Side Code to connect to the server:
jms.properties:
org.omg.CORBA.ORBInitialHost=UNIX MC URL
org.omg.CORBA.ORBInitialPort=7676
Service Locator design to implement resource caching
public class JMSServiceLocator {
private static JMSServiceLocator singletonService = null;
private static QueueConnectionFactory qFactory;
private static Queue queue;
private InitialContext context;
private static Properties properties = new Properties();
private Map cache;
static {
try {
singletonService = new JMSServiceLocator();
} catch (Exception e) {
//error handling
}
}
private JMSServiceLocator() {
try {
loadProperties();
context = new InitialContext(properties);
cache = Collections.synchronizedMap(new HashMap());
} catch (Exception e) {
//error handling
}
}
public static JMSServiceLocator getInstance() {
return singletonService;
}
public QueueConnectionFactory getQueueConnectionFactory() {
String qConnFactoryName = "jms/ReferralConnectionFactory";
qFactory = null;
try {
System.out.println("/********************Comment after Testing*****************************/");
Hashtable env = context.getEnvironment();
System.out.println("**env.size::" + env.size());
Enumeration names = env.keys();
while (names.hasMoreElements()) {
String str = (String) names.nextElement();
System.out.println("**" + str + "=" + env.get(str));
}
System.out.println("/**********************************************************************/");
if (cache.containsKey(qConnFactoryName)) {
qFactory = (QueueConnectionFactory) cache.get(qConnFactoryName);
} else {
qFactory = (QueueConnectionFactory) context.lookup(qConnFactoryName);
cache.put(qConnFactoryName, qFactory);
}
} catch (Exception e) {
//error handling
}
return qFactory;
}
public Queue getQueue() {
String queueName = "jms/ReferralQueue";
queue = null;
try {
if (cache.containsKey(queueName)) {
queue = (Queue) cache.get(queueName);
} else {
queue = (Queue) context.lookup(queueName);
cache.put(queueName, queue);
}
} catch (Exception e) {
//error handling
}
return queue;
}
private static void loadProperties() {
//Load jms properties
}
}
Eventually sending message to the server:
JMSServiceLocator jmsLocator = JMSServiceLocator.getInstance();
QueueConnectionFactory qConnFactory = jmsLocator.getQueueConnectionFactory();
qConnection = qConnFactory.createQueueConnection();
session = qConnection.createSession(false, ession.AUTO_ACKNOWLEDGE);
queue = jmsLocator.getQueue();
// Push and publish the message
messageProducer = session.createProducer(queue);
textMessage = session.createTextMessage();
textMessage.setText(message);
messageProducer.send(textMessage);
Hmmm... Now I observe a strange behavior...
I created a new GlassFish 3.1.2.2 server instance on the client machine with no jndi, no connection factories, and no jms queues what so ever.
I have started this server instance and executed the standalone client application. Strangely, everything works fine and the message is directly being pushed to the remote queue.
Did any one come across this kind of issue? I am suspecting that probably the application is loading the dependent GlassFish jars in the classpath only when a server instance (could be any random instance, totally unrelated) is started.
I have the following jars in my standalone application classpath:
*C:\Program Files\glassfish-3.1.2.2\glassfish\lib\gf-client.jar
*C:\Program Files\glassfish-3.1.2.2\glassfish\lib\appserv-rt.jar
*C:\Program Files\glassfish-3.1.2.2\glassfish\lib\install\applications\jmsra\imqbroker.jar
*C:\Program Files\glassfish-3.1.2.2\glassfish\lib\install\applications\jmsra\imqjmsra.jar
I have also posted this on Oracle JMS and GlassFish forums and haven't got a solution. Any help on this issue would be highly appreciated.
Thanks.
I think you found out by now what the problem was:
the JMS client jars were missing on the client (Client Mc: Windows PC (No server installed)).
You don't need a full Glassfish installation on the clients but only the JMS client jars (gf-client.jar) plus all the other jars referenced by gf-client.jar.