I'm trying to use JavaMail in order to connect to an IMAP Server (on a remote virtual linux machine - Ubuntu 14 LTS) but I'm getting the following exception:
java.net.ConnectException: Connection refused
I've already tried to establish the connection via Telnet and everything works.
The JavaMail version I'm using is 1.5.5 (also tested with 1.4.7) and I'm using the following properties:
Properties properties = System.getProperties();
properties.setProperty("mail.imap.host", SERVER);
properties.setProperty("mail.store.protocol", "imap");
properties.put("mail.imap.port", PORT);
Session session = Session.getInstance(properties, null);
Store store = session.getStore("imap");
store.connect(USERNAME, PASSWORD);
Notes:
It's working on my personal machine
It's working on another external machine
It's failing on the remote linux virtual machine
The IMAP server is on a different machine - which is accessible to all of the previous
I've done some research and some people told that it could be a firewall/blocking issue but how am I able to connect via Telnet?
Thanks.
Edited
The telnet command I've applied in the test-run:
telnet <server_ip> <port>
After this, the connection is successfuly established and I'm able to apply IMAP commands such as list status.
The output from javamail when it fails is the following:
java.net.ConnectException: Connection refused
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:213)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:200)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:529)
at java.net.Socket.connect(Socket.java:478)
at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:233)
at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:189)
at com.sun.mail.iap.Protocol.<init>(Protocol.java:107)
at com.sun.mail.imap.protocol.IMAPProtocol.<init>(IMAPProtocol.java:104)
at com.sun.mail.imap.IMAPStore.protocolConnect(IMAPStore.java:538)
... 12 more
Firewalls usually work port based. This means telnet (23/TCP) can be allowed whereas IMAP (usually 143/993) is blocked.
You should check the firewall and check if the IMAP port is open.
Where is your program running? If you change getDefaultInstance to getInstance does it work?
I've found a solution!!
I performed a network capture on the remote machine and I saw that for some reason the javamail api was using the default IMAP folder and not the one I've selected..
Further tests revealed that changing the property value type to String instead of Integer solved this issue. It's important to notice that this didn't happen on other environments so I'm not sure the reason I had to make this change.
Related
My Windows 7 is providing FTP service using FileZilla Server. On the other hand, a Debian client would like to access the FTP server via Apache FTPsClient. The way I construct the client is shown below:
FTPSClient client = new FTPSClient("TLS", true);
client.setAuthValue(authValue);
client.configure(new FTPClientConfig(FTPClientConfig.SYST_UNIX));
client.connect("127.0.0.1", 990);
client.login("username", "password");
client.execPBSZ(0);
client.execPROT("P");
client.enterLocalPassiveMode();
With the above client on Windows, I can successfully retrieve a list of directory in my FTP server. The same client on Debian is however failed to connect to my Windows server. May anyone give me a hand? Many Thanks^^
The Debian client throws the following exception:
java.net.ConnectException: Connection timed out
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:579)
at org.apache.commons.net.SocketClient.connect(SocketClient.java:188)
at org.apache.commons.net.SocketClient.connect(SocketClient.java:209)
while there is no log for the above connect event.
First of all, many thanks to Martin Prikryl.
Following setup guide, I've created a rule on Firewall allowing access on a port for normal FTP file transfer, but haven't for port 990. After creating new rule for port 990, everything works.
The setup guide for reference
http://www.howtogeek.com/140352/how-to-host-an-ftp-server-on-windows-with-filezilla/
Today I encountered the following problem. When connecting to a database, the following error.Appeal to the remote database by connecting through vpn.
Added necessary firewall ports and even tried to disconnect its(did not help)
Added record to $JAVA_HOME/jre/lib/security/java.policy
grant codeBase "file:/-" {
permission java.security.AllPermission;
};(did not help)
If trying to connect with same data through sql management studio, it works and there is access. from the development environment no connection
Example(string connection = jdbc:sqlserver://DEVMSSQL14.test.com:1433;SCHEMA=test;DATABASENAME=test, sql managment studia = DEVMSSQL14.test.com,1433)
on another computer it works without problems, the same version of the project
It remains only to "Permission denied: connect".Maybe somebody faced with similar
Error:
The TCP/IP connection to the host DEVMSSQL14.test.com, port 1433 has failed. Error: "Permission denied: connect. Verify the connection properties. Make sure that an instance of SQL Server is running on the host and accepting TCP/IP connections at the port. Make sure that TCP connections to the port are not blocked by a firewall.".
In the error message, you have shown like DEVMSSQL14.test.com, 1433 has failed.
I believe, it is correct. I dont think. this host name is correct. which says "TEST" as domain
Open the cmd, try to ping DEVMSSQL14.test.com
Success case :
If you are able to ping, then make sure the services are running for sql in services
Failure case:
Get the right host name to establish the connection
When i tried, i got this message, because i may be out of network.
Pinging DEVMSSQL14.test.com [208.64.121.161] with 32 bytes of data:
Request timed out.
Request timed out.
Try setting a System Property while running the code.
The catch is to introduce this line in code: System.setProperty("java.net.preferIPv4Stack", "true");
Or to pass it in VM option: -Djava.net.preferIPv4Stack=true
I am getting
Caused by: java.net.NoRouteToHostException: No route to host
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:213)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:200)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:529)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:564)
at sun.reflect.GeneratedMethodAccessor638.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.commons.httpclient.protocol.ReflectionSocketFactory.createSocket(ReflectionSocketFactory.java:140)
at org.apache.commons.httpclient.protocol.SSLProtocolSocketFactory.createSocket(SSLProtocolSocketFactory.java:130)
at org.apache.commons.httpclient.HttpConnection.open(HttpConnection.java:707)
at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:387)
at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:171)
at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:397)
at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:323)
javadoc says
Signals that an error occurred while attempting to connect a socket to
a remote address and port. Typically, the remote host cannot be
reached because of an intervening firewall, or if an intermediate
router is down.
Is this error on client side or remote side or it can be either of these?
Basically it says that your client cannot connect to the server due to the address is inaccessible from the client machine.
Please check that the address you are connecting to is accessible, either via ping command in your Command Prompt (Windows) or terminal (Unix-based):
ping <address>
or if it's a web server you can try to check it in your web browser.
The ping command is helpful for me in most cases, since I would know why exactly I can't connect to the address. It can be a mistyped address or like the javadoc suggests, problem with firewall.
Either. It could be a firewall on the client machine blocking outgoing calls or somewhere at the other end.
It may be possible the ping will provide responses, but the application may still fail to connect.
If that is the case, I would suggest using telnet to try and connect to the host using the desired port, telnet host.address port
If the connection is refused then the port on the host will need to be allowed. It that succeeds, but the application still won't connect:
Verify the address:port being used in your application are the same as those used in the telnet test.
It may be a local port on the client blocking the connection, in which case you would need to allow the port on the client
In my case it was solved like this:
1 - Clear the cache with 'yarn cache clean' or 'npm cache clean --force'
2 - after that reboot the pc.
If you clear the cache but do not reboot, the data will still be stored 'somewhere' on the network, so the port will not connect, it is still busy.
After restarting it connects smoothly.
I hope I was helpful!
I had the same issue, and resolve it by disabling the firewall on both sides :
systemctl disable firewalld
service firewalld stop
I had the same issue, I did run iptables flush on host server, this fixed the issue.
# iptables --flush
I have a server, to which a client machine connects. Recently I decided to encrypt the connection with stunnel, so now client program connects not directly to the server, but to localhost:8045 (I checked, and this port is not occupied).
Java code:
URL url = new URL("http://localhost:8045/malibu/GetProviders");
InputStream stream = url.openStream();
And I get the following:
java.net.ConnectException: Connection refused: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:519)
at java.net.Socket.connect(Socket.java:469)
at java.net.Socket.<init>(Socket.java:366)
at java.net.Socket.<init>(Socket.java:180)
. . .
If I try to request the same page using curl, everything is fine.
What can cause such behavior?
EDIT: Yes, there is a listening socket - running netstat -avn | grep 8045 gives:
tcp6 0 0 ::1:8045 :::* LISTEN
The listening socket is bound to the IPv6 loopback address (::1). I recall some issues with Java not supporting dual-stack IPv4/IPv6 systems correctly; this is probably such a case. It is connecting to 127.0.0.1 only (IPv4).
Everything else you have tried (curl, telnet...) will try the IPv6 address first, and then fall back on the IPv4 address if that fails. That's why they work, while the Java application does not.
Try forcing stunnel to bind to 127.0.0.1. You might also try having Java connect to http://[::1]:8045/malibu/GetProviders, though I can't recall if it supports IPv6 addresses in HTTP URLs.
I have Apache on Windows and also connection refused from Java. However debugging the connection and the Apache log shows, that it is actually not a connection problem. Apache returns error 301, permanently moved. Then it provides a redirection url to non-existing port 8080. So something's wrong with the server configuration, probably ServerName directive uses wrong port. Adding a trailing slash to the requested url fixes the problem. The most useful debugging output in my case was given by wget.
It's possible that the accepted answer does not explain the phenomenon. The reporter himself admitted in a comment that finally he used a url with slash at the end.
When I try to connect to cassandra within my java application I receive the exception at the end of this message. I am using pelops library to access database. Database is working on linux and my development environment is on windos 7. Intresting line is
WARNING: 10.0.0.7 NodeContext killing all pooled connections for session 44
10.0.0.7 is the IP of the cassandra node. And I can connect this node with cassandra-cli. After a few hours of googling I decided to ask, what i am doing wrong?
Complete stack trace is below.
SEVERE: org.apache.thrift.transport.TTransportException: java.net.ConnectException: Connection refused: connect
at org.apache.thrift.transport.TSocket.open(TSocket.java:185)
at org.wyki.cassandra.pelops.ThriftPool$Connection.open(ThriftPool.java:329)
at org.wyki.cassandra.pelops.ThriftPool$NodeContext.createConnection(ThriftPool.java:438)
at org.wyki.cassandra.pelops.ThriftPool$NodeContext.access$5(ThriftPool.java:429)
at org.wyki.cassandra.pelops.ThriftPool$NodeContext$1.run(ThriftPool.java:494)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:529)
at java.net.Socket.connect(Socket.java:478)
at org.apache.thrift.transport.TSocket.open(TSocket.java:180)
... 7 more
WARNING: 10.0.0.7 NodeContext killing all pooled connections for session 44
"Connection refused" means that Cassandra isn't listening on the interface you're connecting to. By default Cassandra listens on port 9160 on localhost. You will need to change that if you want to connect externally; read the comments for ThriftAddress in the configuration file.
Pelops isn't doing anything remotely tricky when it comes to making connections to Cassandra so it seems very unlikely it's Pelops specific.
I've just had a quick look at the Hector connection code and it looks pretty much the same:
https://github.com/rantav/hector/blob/master/core/src/main/java/me/prettyprint/cassandra/connection/HThriftClient.java
The cassandra-cli code looks pretty much the same as well:
https://github.com/apache/cassandra/blob/trunk/src/java/org/apache/cassandra/cli/CliMain.java#L57
p.s. Cassandra should not be configured to listen on 0.0.0.0. See the "Why can't I make Cassandra listen on 0.0.0.0 (all my addresses)?" on the Cassandra FAQ.
It seems that this is a problem with pelops, which is a library on top of cassandra's thrift client. It has some problems for connection to Cassandra working on linux and client on a windows machine.
I've got the same exception connecting with "any" client to cassandra remotely:
ConnectException: Connection refused
Looking through SO I couldn't find a quick solution for that, just reading carefully through cassandra docs and comments within cassandra.yaml - they are very handy!
So for me worked following:
change rpc_address value to the hostname or ipaddress you are using to connect to the cassandra instance with the client