URLConnection

[IveCal]

Hello... I have a very big prob here. I have 2 IPs. I dunno what
happened but when I executed the same progs in the 2 IPs: in the 1st
IP, the prog was working but in the 2nd IP, it threw an
java.net.UnknownHostException . . . Here is the code:

import java.io.*;
import java.net.*;
import java.util.*;


public class UCDemo
{
public static void main(String[] args)
{
try
{
String inputLine = "";
String resultString = "";
URL url = new URL("http://www.internic.net");
URLConnection uc = url.openConnection();

if (!(uc instanceof HttpURLConnection))
{
System.err.println ("Wrong connection type");
}

BufferedReader in = new BufferedReader(new
InputStreamReader(uc.getInputStream()));

while ((inputLine = in.readLine()) != null)
resultString+=inputLine;
in.close();

System.out.println(resultString);

}catch(Exception e)
{
e.printStackTrace();
}
}
}


And here is the exception:

java.net.UnknownHostException: www.internic.net
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:177)
at java.net.Socket.connect(Socket.java:507)
at java.net.Socket.connect(Socket.java:457)
at sun.net.NetworkClient.doConnect(NetworkClient.java:157)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:365)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:477)
at sun.net.www.http.HttpClient.<init>(HttpClient.java:214)
at sun.net.www.http.HttpClient.New(HttpClient.java:287)
at sun.net.www.http.HttpClient.New(HttpClient.java:299)
at
sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:792)
at
sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:744)
at
sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:669)
at
sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:913)
at UCDemo.main(UCDemo.java:22)

What went wrong?!? Please help... Thanks a lot.

 

[IveCal]

Hello . . . I have something to add . . . The requested URLs can be
access through IE and Firefox . . .

 

[Gordon Beaton]

Hello... I have a very big prob here. I have 2 IPs. I dunno what
happened but when I executed the same progs in the 2 IPs: in the 1st
IP, the prog was working but in the 2nd IP, it threw an
java.net.UnknownHostException . . . Here is the code:

Behind a firewall? Check your proxy settings.

/gordon

 

[IveCal]

Behind a firewall? Check your proxy settings.

Sorry,sir but I'm not using any firewall or proxy as of the moment . . .

 

[Oliver Wong]

Hello... I have a very big prob here. I have 2 IPs. I dunno what
happened but when I executed the same progs in the 2 IPs: in the 1st
IP, the prog was working but in the 2nd IP, it threw an
java.net.UnknownHostException . . . Here is the code:
[most of the code snipped]
URL url = new URL("http://www.internic.net");

Could it be that one of the two IPs (the failing one) is not connected
to the Internet, but only to your local LAN which doesn't have a DNS or DHCP
server?

- Oliver

 

[IveCal]

Could it be that one of the two IPs (the failing one) is not connected
to the Internet, but only to your local LAN which doesn't have a DNS or DHCP
server?

- Oliver

The requested URLs can be accessed through IE and Firefox . . .
The requested URLs do not work in my Java Applications . . .

 

[Oliver Wong]

The requested URLs can be accessed through IE and Firefox . . .
The requested URLs do not work in my Java Applications . . .

Could it be that your browsers (e.g. IE and Firefox) are intelligent
enough know to use the IP which *IS* connected to the internet?

For example, on my home machine, I have two NICs, and so I have 2 IP
addresses. One of them is connected to the Internet and it's IP is something
like 216.58.97.17, and the other one is connected to my local LAN, and is
something like 192.168.0.1.

There's no DNS server on the 192.168.*.* network, so if I try to resolve
"ww.google.com", I'll fail.

- Oliver