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I am using windows 8 (64bit) but not able to get access to internet using netbeans. When I am trying to update via Help > Check for Update I am getting

Check your network connection, verify that your proxy settings are configured correctly in the NetBeans IDE, or try again later.

When I am trying to access some url with a program in java I am getting error

connection refused: Address is invalid on local machine

whats going on here????

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3 Answers 3

up vote 1 down vote accepted

I need to force Java to use IPv4, to do so set it by command

setx _JAVA_OPTIONS -Djava.net.preferIPv4Stack=true
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Are you behind a proxy server? Go to Tools > Options > General and try to change the network settings according to your network config. EDIT: It may also be a firewall issue.

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No, I am not behind the firewall. –  coure2011 Feb 28 '13 at 16:58

Are you using a proxy server, because if you are then you will need to use a ProxyAuthenticator java class which will can be called within your Java class. This should allow your class to access the Internet.

However, it may be worth checking your NetBeans Internet settings (Tools -> Options -> General) and checking whether a HTTP Proxy authentication is being used. Even so, a ProxyAuthenticator Java class may still be required (assuming a Proxy server is being used). Please see Authenticated HTTP proxy with Java

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