I am working on app (android) that is supposed to visit website & retrieve some data from there. I was thinking it would be nice to use tor so I would not leave so much info about myself.
I've completed scraping part and everything works. Problem is, i can not make proxy accessing internet. I wanted to use Orbot as proxy. I always get 405 error and text:
"this is an http connect tunnel, not a full http proxy it appears you have configured your browser to use this tor port as an http proxy this is not correct: this port is configured as connect tunnel, not an http proxy. please configure your client accordingly. you can also use https; then the client should automatically use http connect"
Code:
UserAgent agent = new UserAgent();
agent.setProxyHost("127.0.0.1");
agent.setProxyPort(8118);
agent.visit("http://stackoverflow.com");
I've tried
System.setProperty("http.proxyHost", "127.0.0.1");
System.setProperty("http.proxyPort", "8118");
instead of the two middle lines from previous code as well plus few other probably not smart things (: and nothing has helped.
From error text about connect tunnel and proxy I figured problem is somewhere in networking but although I searched about it, I couldn't fix it. Perhaps something in Orbot's settings?
My question is, what am I missing please? :)
I'm writing an application in Scala that is using the java HttpClient to try to connect to a url, however I keep on getting the error ERROR Catching java.net.UnknownHostException: my.address.com. The tests are being run using sbt in the terminal on Ubuntu, and when I ping the host from the same location it is able to resolve the ip.
Does anyone have a suggestion of why pinging the host works but my application can't find it?
I have implemented simple proxy server using Java NIO channels, but have a problem, some sites works perfectly, but other give an error about unknown path or redirect on technical page of its hoster with message the resource doesn't exist. Is it my fault or may be some sites don`t allow proxy?
ProxyServer works as this: I enter 'localhost' and in browser I recive site that was set in code. And request from browser I simply resend on target site at such way:
private void connect(SelectionKey key) throws IOException {
SocketChannel channel = ((SocketChannel) key.channel());
Attachment attachment = (Attachment) key.attachment();
channel.write(attachment.buffer);
}
So 'key' - is SelectionKey of target site and in attachment.buffer I store request that was send to proxy server.
So, something worng with my code or its just closed opportunity to proxy by sites?
Update 1. I suppose, I found a problem. Cause I redirect request from localhost to remote server AS IS so in request in field HOST I have 'localhost'. It seems like some sites ignore this fields, other try to use and redirect to 404 page, cause can't find 'localhost' I`m asking for. So question is how to change field 'Host' in request on destination server name?
The target server doesn't know anything about your NIO code, or whether you are a proxy or a real client.
If you got an error page, the proxy is working, and it is the resource being proxied that is the problem: it doesn't exist, you don't have access, etc. Nothing you can do about that in your code and no reason why you should worry. Just send the error page to the client, same as you would send anything else.
Why is that method called connect() when it doesn't connect and does do something else?
I found a problem. filed HOST after proxy contains 'localhost', so some sites accept it, other not. Replace value of this fields with real host fix the problem.
I have configured a proxy in my java source code as:
systemSettings.put("http.proxyHost", "www.proxyserver.com");
systemSettings.put("http.proxyPort", "8080");
systemSettings.put("http.nonProxyHosts", "10.x.y.z");
Here 10.x.y.z is the actual IP of my weblogic server.
But whenever code tried to connect to weblogic server, I receive error as:
Caused by: java.net.ConnectException: t3://10.x.y.z:7001: Destination
unreachable; nested exception is: java.net.ProtocolException:
unrecognized response from proxy: 'HTTP/1.0 403 Forbidden'; No
available router to destination at
weblogic.rjvm.RJVMFinder.findOrCreateInternal(RJVMFinder.java:216) at
weblogic.rjvm.RJVMFinder.findOrCreate(RJVMFinder.java:170) at
weblogic.rjvm.ServerURL.findOrCreateRJVM(ServerURL.java:153) at
weblogic.jndi.WLInitialContextFactoryDelegate$1.run(WLInitialContextFactoryDelegate.java:345)
at
weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:363)
at
weblogic.security.service.SecurityManager.runAs(SecurityManager.java:146)
at
weblogic.jndi.WLInitialContextFactoryDelegate.getInitialContext(WLInitialContextFactoryDelegate.java:340)
It seems that setting http.nonProxyHosts is not working as expected. I tried to find solution over the Internet, but most of them says remove proxy settings. I can not remove proxy, as my code tries to connect to some of the Internet URLs. Also note that, weblogic server is on remote machine.
Can you please give me a hint, what must be the issue here?
Have a look at this OTN thread.
From 3rd comment :
You are setting nonProxyHosts, which doesn't exist as a system property, via System.setProperties().
I haven't read all so far, but it seems the system.properties is not the convenient way to set
nonProxyHosts.
Did you tried to set it from command line ?
-Dhttp.nonProxyHosts="*.foo.com|localhost".
I resolved the issue. I had setup the proxy initially when connection with weblogic was setup. So due to some network restrictions I believe it didnt work. In modified code, I used the same 3 lines to setup proxy:
System.setProperty("java.net.useSystemProxies", "false");
System.setProperty("http.proxyHost", "www.proxyserver.com");
System.setProperty("http.proxyPort", "8080");
The only difference is, I did it at exact place where I needed. So for initial connection setup with weblogic proxy wont be used. I also did not have to bypass, weblogic server URL to not to use proxy.
#Arcadien: I appreciate your efforts to help me. Thanks.
What are the steps I should take to solve the error:
java.net.UnknownHostException: Invalid hostname for server: local
I added the new virtual host name at Android emulator but the result returns to
java.net.UnknownHostException virtualhostname at
java.net.InetAddress.lookUpHostByName(InetAddress.java:506)
When I type my virtualhost URL on my PC, it works on display. Then again, when I ran on Emulator and check on Logcat, I couldn't be able to read or check the HTTP status if 200, 202, or an error code number. It simply returned to UnknownHostException
I was having the same issue on my mac. I found the issue when I pinged my $HOSTNAME from terminal and it returned ping: cannot resolve myHostName: Unknown host.
To resolve:
Do echo $HOSTNAME on your terminal.
Whatever hostname it shows (lets say myHostName), try to ping it : ping myHostName. If it returns ping: cannot resolve myHostName: Unknown host then add an entry into your /etc/hosts file.
For that edit /etc/hosts file and add following:
127.0.0.1 myHostName
What the exception is really saying is that there is no known server with the name "local". My guess is that you're trying to connect to your local computer. Try with the hostname "localhost" instead, or perhaps 127.0.0.1 or ::1 (the last one is IPv6).
From the javadocs:
Thrown to indicate that the IP address
of a host could not be determined.
127.0.0.1or ::1 or "localhost" should always be the loopback interface, so if that doesn't work I'd be really surprised.
If there really is a server called "local" on your network - examine your DNS settings or add it to your hosts file.
java.net.UnknownHostException: Host is unresolved:
Thrown to indicate that the IP address of a host could not be determined.
This exception is also raised when you are connected to a valid wifi but router does not receive the internet. Its very easy to reproduce this:
Connect to a valid wifi
Now remove the cable from the router while router is pluged-in
You will observe this error!!
You can't really solve this, You can only notify the user gracefully. (something like - "Unable to make a connection")
This is not specific to the question, but this question showed up when I was Googling for the mentioned UnknownHostException, and the fix is not found anywhere else so I thought I'd add an answer here.
The exception that was continuously received was:
java.net.UnknownHostException: google.com
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:184)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at java.net.Socket.connect(Socket.java:538)
at java.net.Socket.<init>(Socket.java:434)
at java.net.Socket.<init>(Socket.java:211)
...
No matter how I tried to connect to any valid host, printing it in the terminal would not help either. Everything was right.
The Solution
Not calling trim() for the host string which contained whitespace. In writing a proxy server the host was obtained from HTTP headers with the use of split(":") by semicolons for the HOST header. This left whitespace, and causes the UnknownHostException as a host with whitespace is not a valid host. Doing a host = host.trim() on the String host solved the ambiguous issue.
Your hostname is missing. JBoss uses this environment variable ($HOSTNAME) when it connects to the server.
[root#xyz ~]# echo $HOSTNAME
xyz
[root#xyz ~]# ping $HOSTNAME
ping: unknown host xyz
[root#xyz ~]# hostname -f
hostname: Unknown host
There are dozens of things that can cause this. Please comment if you discover a new reason.
For a hack until you can permanently resolve this issue on your server, you can add a line to the end of your /etc/hosts file:
127.0.0.1 xyz.xxx.xxx.edu xyz
This might happen due to various reasons
1) Check if you have VPN connected, you might get this error sometimes if yes
"Your hostname, localhost resolves to a loopback address: 127.0.0.1; using 10.xxx.1.193 instead (on interface cscotun0)"
2) Check your $HOSTNAME
3) try to ping $HOSTNAME on commandline and if it doesnt work, tweak the system settings to make your local host respond to pings
Try the following :
String url = "http://www.google.com/search?q=java";
URL urlObj = (URL)new URL(url.trim());
HttpURLConnection httpConn =
(HttpURLConnection)urlObj.openConnection();
httpConn.setRequestMethod("GET");
Integer rescode = httpConn.getResponseCode();
System.out.println(rescode);
Trim() the URL
Trying to connect to your local computer.try with the hostname "localhost" instead or perhaps ::/ - the last one is ipv6
Please try to set SPARK_LOCAL_IP environment variable to the ip address(can be localhost i.e. your own ip address) you want to connect. E.g.
$ export SPARK_LOCAL_IP=182.95.208.152
This way you will not be required to alter existing linux settings.
Worked for me, hope helps you too.
Connect your mobile with different wifi connection with different service provider.
I don't know the exact issue but i could not connect to server with a specific service provider but it work when i connected to other service provider. So try it!
I had this issue in my android app when grabbing an xml file the format of my link was not valid, I reformatted with the full url and it worked.
If you are here because your emulator gives you that Exception, Go to Tools > AVD Manager in your android emulator and Cold boot your Emulator.
I had the same issue.
Restart docker was the fix for me. For some reason it needed a restart, I don´t know why, but it worked.
If your /etc/localhosts file has entry as below:
Add hostname entry as below:
127.0.0.1 local host (add your hostname here)
::1 (add hostname here) (the last one is IPv6).
This should resolve the issue.