59 lines
1.8 KiB
Java
59 lines
1.8 KiB
Java
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package cc.fascinated.common;
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import lombok.NonNull;
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import lombok.SneakyThrows;
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import lombok.experimental.UtilityClass;
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import org.xbill.DNS.Record;
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import org.xbill.DNS.*;
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import java.net.InetAddress;
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import java.net.InetSocketAddress;
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/**
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* @author Braydon
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*/
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@UtilityClass
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public final class DNSUtils {
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private static final String SRV_QUERY_PREFIX = "_minecraft._tcp.%s";
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/**
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* Resolve the hostname to an {@link InetSocketAddress}.
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*
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* @param hostname the hostname to resolve
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* @return the resolved {@link InetSocketAddress}
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*/
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@SneakyThrows
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public static InetSocketAddress resolveSRV(@NonNull String hostname) {
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Record[] records = new Lookup(SRV_QUERY_PREFIX.formatted(hostname), Type.SRV).run(); // Resolve SRV records
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if (records == null) { // No records exist
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return null;
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}
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String host = null;
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int port = -1;
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for (Record record : records) {
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SRVRecord srv = (SRVRecord) record;
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host = srv.getTarget().toString().replaceFirst("\\.$", "");
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port = srv.getPort();
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}
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return host == null ? null : new InetSocketAddress(host, port);
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}
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/**
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* Resolve the hostname to an {@link InetAddress}.
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*
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* @param hostname the hostname to resolve
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* @return the resolved {@link InetAddress}
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*/
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@SneakyThrows
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public static InetAddress resolveA(@NonNull String hostname) {
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Record[] records = new Lookup(hostname, Type.A).run(); // Resolve A records
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if (records == null) { // No records exist
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return null;
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}
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InetAddress address = null;
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for (Record record : records) {
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address = ((ARecord) record).getAddress();
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}
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return address;
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}
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}
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