DnsServerAddresses Class — netty Architecture

Source Code

resolver-dns/src/main/java/io/netty/resolver/dns/DnsServerAddresses.java lines 30–209

@SuppressWarnings("IteratorNextCanNotThrowNoSuchElementException")
public abstract class DnsServerAddresses {
    /**
     * @deprecated Use {@link DefaultDnsServerAddressStreamProvider#defaultAddressList()}.
     * <p>
     * Returns the list of the system DNS server addresses. If it failed to retrieve the list of the system DNS server
     * addresses from the environment, it will return {@code "8.8.8.8"} and {@code "8.8.4.4"}, the addresses of the
     * Google public DNS servers.
     */
    @Deprecated
    public static List<InetSocketAddress> defaultAddressList() {
        return DefaultDnsServerAddressStreamProvider.defaultAddressList();
    }

    /**
     * @deprecated Use {@link DefaultDnsServerAddressStreamProvider#defaultAddresses()}.
     * <p>
     * Returns the {@link DnsServerAddresses} that yields the system DNS server addresses sequentially. If it failed to
     * retrieve the list of the system DNS server addresses from the environment, it will use {@code "8.8.8.8"} and
     * {@code "8.8.4.4"}, the addresses of the Google public DNS servers.
     * <p>
     * This method has the same effect with the following code:
     * <pre>
     * DnsServerAddresses.sequential(DnsServerAddresses.defaultAddressList());
     * </pre>
     * </p>
     */
    @Deprecated
    public static DnsServerAddresses defaultAddresses() {
        return DefaultDnsServerAddressStreamProvider.defaultAddresses();
    }

    /**
     * Returns the {@link DnsServerAddresses} that yields the specified {@code addresses} sequentially. Once the
     * last address is yielded, it will start again from the first address.
     */
    public static DnsServerAddresses sequential(Iterable<? extends InetSocketAddress> addresses) {
        return sequential0(sanitize(addresses));
    }

    /**
     * Returns the {@link DnsServerAddresses} that yields the specified {@code addresses} sequentially. Once the
     * last address is yielded, it will start again from the first address.
     */
    public static DnsServerAddresses sequential(InetSocketAddress... addresses) {
        return sequential0(sanitize(addresses));
    }

    private static DnsServerAddresses sequential0(final List<InetSocketAddress> addresses) {
        if (addresses.size() == 1) {
            return singleton(addresses.get(0));
        }

        return new DefaultDnsServerAddresses("sequential", addresses) {
            @Override
            public DnsServerAddressStream stream() {
                return new SequentialDnsServerAddressStream(addresses, 0);
            }
        };
    }

    /**
     * Returns the {@link DnsServerAddresses} that yields the specified {@code address} in a shuffled order. Once all
     * addresses are yielded, the addresses are shuffled again.
     */
    public static DnsServerAddresses shuffled(Iterable<? extends InetSocketAddress> addresses) {
        return shuffled0(sanitize(addresses));
    }

    /**
     * Returns the {@link DnsServerAddresses} that yields the specified {@code addresses} in a shuffled order. Once all
     * addresses are yielded, the addresses are shuffled again.
     */
    public static DnsServerAddresses shuffled(InetSocketAddress... addresses) {
        return shuffled0(sanitize(addresses));
    }

    private static DnsServerAddresses shuffled0(List<InetSocketAddress> addresses) {
        if (addresses.size() == 1) {
            return singleton(addresses.get(0));
        }