AbstractDnsRecord Class — netty Architecture

Source Code

codec-dns/src/main/java/io/netty/handler/codec/dns/AbstractDnsRecord.java lines 29–163

public abstract class AbstractDnsRecord implements DnsRecord {

    private final String name;
    private final DnsRecordType type;
    private final short dnsClass;
    private final long timeToLive;
    private int hashCode;

    /**
     * Creates a new {@link #CLASS_IN IN-class} record.
     *
     * @param name the domain name
     * @param type the type of the record
     * @param timeToLive the TTL value of the record
     */
    protected AbstractDnsRecord(String name, DnsRecordType type, long timeToLive) {
        this(name, type, CLASS_IN, timeToLive);
    }

    /**
     * Creates a new record.
     *
     * @param name the domain name
     * @param type the type of the record
     * @param dnsClass the class of the record, usually one of the following:
     *                 <ul>
     *                     <li>{@link #CLASS_IN}</li>
     *                     <li>{@link #CLASS_CSNET}</li>
     *                     <li>{@link #CLASS_CHAOS}</li>
     *                     <li>{@link #CLASS_HESIOD}</li>
     *                     <li>{@link #CLASS_NONE}</li>
     *                     <li>{@link #CLASS_ANY}</li>
     *                 </ul>
     * @param timeToLive the TTL value of the record
     */
    protected AbstractDnsRecord(String name, DnsRecordType type, int dnsClass, long timeToLive) {
        checkPositiveOrZero(timeToLive, "timeToLive");
        // Convert to ASCII which will also check that the length is not too big.
        // See:
        //   - https://github.com/netty/netty/issues/4937
        //   - https://github.com/netty/netty/issues/4935
        this.name = appendTrailingDot(IDNtoASCII(name));
        this.type = checkNotNull(type, "type");
        this.dnsClass = (short) dnsClass;
        this.timeToLive = timeToLive;
    }

    private static String IDNtoASCII(String name) {
        checkNotNull(name, "name");
        if (PlatformDependent.isAndroid() && DefaultDnsRecordDecoder.ROOT.equals(name)) {
            // Prior Android 10 there was a bug that did not correctly parse ".".
            //
            // See https://github.com/netty/netty/issues/10034
            return name;
        }
        return IDN.toASCII(name);
    }

    private static String appendTrailingDot(String name) {
        if (name.length() > 0 && name.charAt(name.length() - 1) != '.') {
            return name + '.';
        }
        return name;
    }

    @Override
    public String name() {
        return name;
    }

    @Override
    public DnsRecordType type() {
        return type;
    }

    @Override
    public int dnsClass() {
        return dnsClass & 0xFFFF;
    }

    @Override