Hot wo specify a custom DNS Resolver

[carter-ya]

Describe what you would like to know or do
I want to specify a custome DNS resolver, like apache http client

/**
 * Users may implement this interface to override the normal DNS lookup offered
 * by the OS.
 *
 * @since 4.2
 */
public interface DnsResolver {

    /**
     * Returns the IP address for the specified host name, or null if the given
     * host is not recognized or the associated IP address cannot be used to
     * build an InetAddress instance.
     *
     * @see InetAddress
     *
     * @param host
     *            The host name to be resolved by this resolver.
     * @return The IP address associated to the given host name, or null if the
     *         host name is not known by the implementation class.
     */
    InetAddress[] resolve(String host) throws UnknownHostException;

}

[marci4]

Hello @liukefeng2008,

could you please describe your usecase and what you are trying to achieve?

Best regards,
Marcel

[carter-ya]

Hello, I want to access some websocket resources, eg: (wss://api.fcoin.com/v2/ws).
In some countries,The default dns parsing behavior will resolve the wrong ip address, So I want to specify a custom dns resolver.

1. how-to-configure-hostname-resolution-to-use-a-custom-dns-server-in-java
2. how-to-override-dns-in-http-connections-in-java

I want to use the second way, but this library(Java-WebSocket) does not support this method. Is it possible to add a custom dns resolver?

[marci4]

Hello @liukefeng2008

Thank you for a feedback.
Do I understand you correctly, you just need an API to set a InetAddress instead of an URL?

Best regards,
Marcel

[carter-ya]

I can't set the IP directly. Because the server only respond by the host.
If url wss://api.fcoin.com/v2/ws, it's work for me.
If url wss://x.x.x.x/v2/ws, it's not work.

@marci4 look forward to your reply

[marci4]

I am not really sure if there are reallife usecases for this.

If someone has the time, feel free to implement a solution and we discuss it on the PR.

Best regards,
Marcel