org.xbill.DNS.Cache Java Examples

@Override
protected List<String> fetch() {

  try {
    Resolver resolver = new SimpleResolver();
    // dns resolvers may take a long time to return a response.
    resolver.setTimeout(timeout);
    Lookup l =
        new Lookup(StringUtils.endsWith(hostname, ".") ? hostname : hostname + ".", Type.TXT);
    // always make sure the cache is empty
    l.setCache(new Cache());
    l.setResolver(resolver);
    Record[] records = l.run();
    if (records != null && records.length > 0) {
      return parse(records[0]);
    }
  } catch (Exception e) {
    log.error("Problem while adding Google resolvers, continue without", e);
  }

  log.error("No Google resolver addresses found");
  return Collections.emptyList();
}
 

@Before
public void setUp() throws Exception {
    dnsServer = new TestableDNSServer();

    dnsServer.configure(FileConfigurationProvider.getConfig(new ByteArrayInputStream(DNS_SERVER_CONFIG)));
    dnsServer.init();

    defaultCache = Lookup.getDefaultCache(DClass.IN);
    defaultResolver = Lookup.getDefaultResolver();
    defaultSearchPaths = Lookup.getDefaultSearchPath();
    Lookup.setDefaultCache(null, DClass.IN);
    Lookup.setDefaultResolver(null);
    Lookup.setDefaultSearchPath(new Name[]{});

    dnsServer.setResolver(null);
    mockedCache = mock(Cache.class);
}
 

public <T extends Record> RRset findExactMatch(Name name, int type, int dclass, boolean glue) {
  Zone zone = findBestZone(name);
  if (zone != null) {
    return zone.findExactMatch(name, type);
  } else {
    List<RRset> rrsets;
    Cache cache = getCache(dclass);
    if (glue) {
      rrsets = cache.findAnyRecords(name, type);
    } else {
      rrsets = cache.findRecords(name, type);
    }
    if (rrsets == null) {
      return null;
    } else {
      return rrsets.get(0); /* not quite right */
    }
  }
}
 

private void addCacheNS(Message response, Cache cache, Name name) {
  SetResponse sr = cache.lookupRecords(name, Type.NS, Credibility.HINT);
  if (!sr.isDelegation()) {
    return;
  }
  RRset nsRecords = sr.getNS();
  for (Record r : nsRecords.rrs()) {
    response.addRecord(r, Section.AUTHORITY);
  }
}
 

@PostConstruct
public void init() throws Exception {
    LOGGER.debug("DNSService init...");

    // If no DNS servers were configured, default to local host
    if (dnsServers.isEmpty()) {
        try {
            dnsServers.add(InetAddress.getLocalHost().getHostName());
        } catch (UnknownHostException ue) {
            dnsServers.add("127.0.0.1");
        }
    }

    // Create the extended resolver...
    final String[] serversArray = dnsServers.toArray(String[]::new);

    if (LOGGER.isInfoEnabled()) {
        for (String aServersArray : serversArray) {
            LOGGER.info("DNS Server is: " + aServersArray);
        }
    }

    try {
        resolver = new ExtendedResolver(serversArray);
    } catch (UnknownHostException uhe) {
        LOGGER.error("DNS service could not be initialized.  The DNS servers specified are not recognized hosts.", uhe);
        throw uhe;
    }

    cache = new Cache(DClass.IN);
    cache.setMaxEntries(maxCacheSize);
    cache.setMaxNCache(negativeCacheTTL);

    if (setAsDNSJavaDefault) {
        Lookup.setDefaultResolver(resolver);
        Lookup.setDefaultCache(cache, DClass.IN);
        Lookup.setDefaultSearchPath(searchPaths);
        LOGGER.info("Registered cache, resolver and search paths as DNSJava defaults");
    }

    // Cache the local hostname and local address. This is needed because
    // the following issues:
    // JAMES-787
    // JAMES-302
    InetAddress addr = getLocalHost();
    localCanonicalHostName = addr.getCanonicalHostName();
    localHostName = addr.getHostName();
    localAddress = addr.getHostAddress();

    LOGGER.debug("DNSService ...init end");
}
 

public void setCache(Cache c) {
    cache = c;
}