I'm having some issues for creating a simple socket, I'm new to this kind of stuff sorry for a simple question thanks. I tried to follow some tutorial for creating Sockets in java and tried this so far
try {
Socket chatSocket = new Socket("127.0.0.1", 4242);
System.out.println("connection established");
}
catch (IOException e) {
e.printStackTrace();
}
I'm getting this kind of error
java.net.ConnectException: Connection refused: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at application.main.main(main.java:15)
and when I try to access my localhost from my browser I see this error
The connection to '127.0.0.1' failed.
Error: ConnectionRefused (0x274d).
System.Net.Sockets.SocketException No connection could be made because the
target machine actively refused it 127.0.0.1:4242
I have no idea what is happening because, just followed what the tutorial does. I think the issue is on my local machine but I have no idea what is making the connection refuse
Related
I am trying to execute a crawler program from my office. A very basic one which is available in internet and which works fine in my home PC. However while I am trying to run the same program in my office PC i am getting connect timed out error. I thought it was proxy problem and tried accessing some site from eclipse internal browser and it worked fine also.
Document doc = Jsoup.connect("http://flipkart.com/").timeout(0).get();
Please find below my stack trace
Exception in thread "main" java.net.ConnectException: Connection timed out: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at sun.net.NetworkClient.doConnect(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.<init>(Unknown Source)
at sun.net.www.http.HttpClient.New(Unknown Source)
at sun.net.www.http.HttpClient.New(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.connect(Unknown Source)
at org.jsoup.helper.HttpConnection$Response.execute(HttpConnection.java:449)
at org.jsoup.helper.HttpConnection$Response.execute(HttpConnection.java:434)
at org.jsoup.helper.HttpConnection.execute(HttpConnection.java:181)
at org.jsoup.helper.HttpConnection.get(HttpConnection.java:170)
at org.syntel.crawler.Crawler.processPage(Crawler.java:44)
at org.syntel.crawler.Crawler.main(Crawler.java:20)
How can I fix this problem?
#alkis made the suggestion:
Try setting a user agent. ff you are using a proxy check this other question:
How to add proxy support to Jsoup (HTML parser)?
Try using:
System.out.println("Testing JSOUP\n--------------");
Proxy proxy = new Proxy( //
Proxy.Type.HTTP, //
InetSocketAddress.createUnresolved("www.yourPROXY.com", 80) //
);
Document doc = Jsoup.connect("http://en.wikipedia.org/").proxy(proxy).get();
Elements newsHeadlines = doc.select("#mp-itn b a");
System.out.println(newsHeadlines.html());
So i have read up on similar questions but i haven't found anything that i fully understand yet.
http://www.coderanch.com/t/487650/java/java/java-rmi-ConnectException-Connection-refused
http://protegewiki.stanford.edu/wiki/Troubleshooting_Client_Server_Connections
what is RMI registry
http://docs.oracle.com/javase/7/docs/technotes/guides/rmi/faq.html#domain
I have a server which is crashing every few days and I am trying to work out where the problem lies. The software is running in an environment supplied by the customer and i need to know if we are the problem or windows/the network.
My question is... RMI registry, Is that something that java creates or is it something that exists in windows anyway? Why would a connection to localhost suddenly become unavailable or refused? Is there anything that i can do to troubleshoot immediately?
The RMI configuration is here:
<RMIService>
<class>com.s.i.system.RMIService</class>
<server name="Server">
<host>localhost</host>
<timeout>0</timeout>
</server>
</RMIService>
Here is the error that is created in the logs.
2015-04-02 16:52:10,057 ERROR [main] com...........gui.initialise.ClientInitialise - java.rmi.ConnectException: Connection refused to host: localhost; nested exception is:
java.net.ConnectException: Connection refused: connect
at sun.rmi.transport.tcp.TCPEndpoint.newSocket(Unknown Source)
at sun.rmi.transport.tcp.TCPChannel.createConnection(Unknown Source)
at sun.rmi.transport.tcp.TCPChannel.newConnection(Unknown Source)
at sun.rmi.server.UnicastRef.newCall(Unknown Source)
at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
at java.rmi.Naming.lookup(Unknown Source)
at com.s.i.system.RMIService.lookup(RMIService.java:570)
at com.s.i.system.RMIService.lookupServer(RMIService.java:377)
at com.s.i.process.RemoteRequestHandler$Dispatcher.run(RemoteRequestHandler.java:282)
at com.s.i.process.RemoteRequestHandler$Dispatcher.start(RemoteRequestHandler.java:269)
at com.s.i.process.RemoteRequestHandler.handle(RemoteRequestHandler.java:96)
at com.s.i.process.RequestDispatcher.dispatch(RequestDispatcher.java:136)
at com.s.i.client.ClientInitialiser.initialiseEnvironment(ClientInitialiser.java:498)
at com.s.i.client.ClientInitialiser.performEnvironmentInit(ClientInitialiser.java:145)
at com.s.i.client.ClientInitialiser.initialise(ClientInitialiser.java:128)
at com.s.i.client.ClientInitialiser.initialise(ClientInitialiser.java:106)
at com.s.i.gui.initialise.ClientInitialise.createInitialiser(ClientInitialise.java:136)
at com.s.i.gui.initialise.ClientInitialise.<init>(ClientInitialise.java:155)
at com.s.i.client.Client.initialise(Client.java:118)
at com.s.i.client.Client.main(Client.java:147)
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(Unknown Source)
at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at sun.rmi.transport.proxy.RMIDirectSocketFactory.createSocket(Unknown Source)
at sun.rmi.transport.proxy.RMIMasterSocketFactory.createSocket(Unknown Source)
... 20 more
The RMI Registry is a component of the JRE, not of Windows. Clearly it is crashing, or far more probably it is being closed down incorrectly for some reason. I've never seen an RMI Registry crash in 18 years.
I have created a service that opens a lots of remote resources; for a lot, i mean over 200k / day, but i think that less than 1000 connections are opened at the same time. After i connect to the remote resource, i open an input stream to get the file content.
Sometimes i get the following exception
java.net.BindException: Address already in use: connect
at java.net.TwoStacksPlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at sun.net.NetworkClient.doConnect(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.<init>(Unknown Source)
at sun.net.www.http.HttpClient.New(Unknown Source)
at sun.net.www.http.HttpClient.New(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.connect(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.followRedirect(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
at java.net.HttpURLConnection.getResponseCode(Unknown Source)
at sitodove.varie.ExternalLinksChecker.getWebPage(ExternalLinksChecker.java:121)
at sitodove.varie.ExternalLinksChecker.run(ExternalLinksChecker.java:37)
This service starts correctly, opening just a few ports for limited needs because it needs to offer some services. While it is running, i get the above exception, what may be the cause?
A port is already being used and you try to bind it again. Check in your application if your are not trying to use a port twice.
Probably, you're trying to open a port that is already open.
open the terminal an type telnet to see if that port is already open. ie.
telnet localhost 9889
Trying ::1...
telnet: connect to address ::1: Connection refused
if this command returns Connection refused, that means the port is free.
Getting java.net.SocketException: Malformed reply from SOCKS server exception for the following socket creation.I am not using any SOCKS Server & and it is just a stand alone program, this the starting line & getting exception here only.I am using reflection API also.
public static String tcpSend(String ip, int port, int timeout, String content)
{
try
{
clientSocket = new Socket(ip, port);
.....
}
.....
}
Calling from other method like the following:
SendReceiveCanMessage.tcpSend("localhost", 8000, 5000,"start");
The folling is the complete stacktrace.
java.net.SocketException: Malformed reply from SOCKS server
at java.net.SocksSocketImpl.readSocksReply(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.(Unknown Source)
at java.net.Socket.(Unknown Source)
at com.cognizant.vehiclespy.SendReceiveCanMessage.tcpSend(SendReceiveCanMessage.java:19)
at Executer.executeTest3_12(Executer.java:672)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.cognizant.controller.SupervisoryControl.execute(SupervisoryControl.java:111)
at supervisorycontrol.SupervisoryControlView$ExecuteThread.run(SupervisoryControlView.java:466)
Somewhere you have the system property 'socksProxyHost' set. Find it and nuke it.
I have a problem with access the gmail from my working area. This is my code. It works in my home when network settings are default. The main problem is, in the working area there is more security on computers and network like firewalls etc..
I have to find a solution for run this script behind the firewall. Closing the firewall is not a permanent solution.
Also I added the error message to the below. Any help is appreciated.
`com.sun.mail.util.MailConnectException: Couldn't connect to host, port: imap.gmail.com, 993; timeout -1;
nested exception is:
java.net.ConnectException: Connection timed out: connect
at com.sun.mail.imap.IMAPStore.protocolConnect(IMAPStore.java:672)
at javax.mail.Service.connect(Service.java:345)
at javax.mail.Service.connect(Service.java:226)
at unreadmails.MailReader.<init>(MailReader.java:23)
at unreadmails.MailReader.main(MailReader.java:12)
Caused by: java.net.ConnectException: Connection timed out: connect
at java.net.TwoStacksPlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:297)
at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:229)
at com.sun.mail.iap.Protocol.<init>(Protocol.java:116)
at com.sun.mail.imap.protocol.IMAPProtocol.<init>(IMAPProtocol.java:115)
at com.sun.mail.imap.IMAPStore.newIMAPProtocol(IMAPStore.java:689)
at com.sun.mail.imap.IMAPStore.protocolConnect(IMAPStore.java:638)
... 4 more`