import com.sun.istack.Nullable; //导入依赖的package包/类
/**
 * Returns the default (first) host name associated by the provided
 * nameserver with the address bound to the specified network interface
 * 
 * @param strInterface
 *            The name of the network interface to query (e.g. eth0)
 * @param nameserver
 *            The DNS host name
 * @return The default host names associated with IPs bound to the network
 *         interface
 * @throws UnknownHostException
 *             If one is encountered while querying the default interface
 */
public static String getDefaultHost(@Nullable String strInterface,
                                    @Nullable String nameserver,
                                    boolean tryfallbackResolution)
  throws UnknownHostException {
  if (strInterface == null || "default".equals(strInterface)) {
    return cachedHostname;
  }

  if (nameserver != null && "default".equals(nameserver)) {
    nameserver = null;
  }

  String[] hosts = getHosts(strInterface, nameserver, tryfallbackResolution);
  return hosts[0];
}
 

import com.sun.istack.Nullable; //导入依赖的package包/类
/**
     * Prints the usage screen and exits the process.
     *
     * @param opts
     *      If the parsing of options have started, set a partly populated
     *      {@link Options} object.
     */
    public static void usage( @Nullable Options opts, boolean privateUsage ) {
        if( privateUsage ) {
            System.out.println(Messages.format(Messages.DRIVER_PRIVATE_USAGE));
        } else {
            System.out.println(Messages.format(Messages.DRIVER_PUBLIC_USAGE));
        }
        
        // do not show plugin usage
//        if( opts!=null && opts.getAllPlugins().size()!=0 ) {
//            System.out.println(Messages.format(Messages.ADDON_USAGE));
//            for (Plugin p : opts.getAllPlugins()) {
//                System.out.println(p.getUsage());
//            }
//        }
    }
 

import com.sun.istack.Nullable; //导入依赖的package包/类
/**
 * Returns the hostname associated with the specified IP address by the
 * provided nameserver.
 *
 * Loopback addresses 
 * @param hostIp The address to reverse lookup
 * @param ns The host name of a reachable DNS server
 * @return The host name associated with the provided IP
 * @throws NamingException If a NamingException is encountered
 */
public static String reverseDns(InetAddress hostIp, @Nullable String ns)
  throws NamingException {
  //
  // Builds the reverse IP lookup form
  // This is formed by reversing the IP numbers and appending in-addr.arpa
  //
  String[] parts = hostIp.getHostAddress().split("\\.");
  String reverseIP = parts[3] + "." + parts[2] + "." + parts[1] + "."
    + parts[0] + ".in-addr.arpa";

  DirContext ictx = new InitialDirContext();
  Attributes attribute;
  try {
    attribute = ictx.getAttributes("dns://"               // Use "dns:///" if the default
                       + ((ns == null) ? "" : ns) +
                       // nameserver is to be used
                       "/" + reverseIP, new String[] { "PTR" });
  } finally {
    ictx.close();
  }

  String hostname = attribute.get("PTR").get().toString();
  int hostnameLength = hostname.length();
  if (hostname.charAt(hostnameLength - 1) == '.') {
    hostname = hostname.substring(0, hostnameLength - 1);
  }
  return hostname;
}
 

import com.sun.istack.Nullable; //导入依赖的package包/类
@Override
public boolean giveUpTask(String taskId, @Nullable String reason) throws TException {
    boolean res = worker.discardTask(taskId);
    /*TODO*/
    Optional.ofNullable(reason).ifPresent(System.out::println);
    return res;
}
 

import com.sun.istack.Nullable; //导入依赖的package包/类
@Override public boolean contains(@Nullable Object obj) {
    if (obj instanceof List<?>) {
        List<?> list = (List<?>) obj;
        return isPermutation(inputList, list);
    }
    return false;
}
 

import com.sun.istack.Nullable; //导入依赖的package包/类
private List<AtlasClassification> getClassifications(AtlasVertex instanceVertex, @Nullable String classificationNameFilter) throws AtlasBaseException {
    List<AtlasClassification> classifications = new ArrayList<>();
    List<String> classificationNames = GraphHelper.getTraitNames(instanceVertex);

    if (CollectionUtils.isNotEmpty(classificationNames)) {
        for (String classificationName : classificationNames) {
            AtlasClassification classification;
            if (StringUtils.isNotEmpty(classificationNameFilter)) {
                if (classificationName.equals(classificationNameFilter)) {
                    classification = getClassification(instanceVertex, classificationName);
                    classifications.add(classification);
                    return classifications;
                }
            } else {
                classification = getClassification(instanceVertex, classificationName);
                classifications.add(classification);
            }
        }


        if (StringUtils.isNotEmpty(classificationNameFilter)) {
            //Should not reach here if classification present
            throw new AtlasBaseException(AtlasErrorCode.CLASSIFICATION_NOT_FOUND, classificationNameFilter);
        }
    }
    return classifications;
}