org.minidns.iterative

Class ReliableDnsClient

java.lang.Object

org.minidns.AbstractDnsClient

org.minidns.iterative.ReliableDnsClient

Direct Known Subclasses:

DnssecClient

public class ReliableDnsClient
extends AbstractDnsClient

A DNS client using a reliable strategy. First the configured resolver of the system are used, then, in case there is no answer, a fall back to iterative resolving is performed.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ReliableDnsClient.Mode

Nested classes/interfaces inherited from class org.minidns.AbstractDnsClient

AbstractDnsClient.IpVersionSetting

Field Summary

Fields inherited from class org.minidns.AbstractDnsClient

cache, dataSource, DEFAULT_CACHE, DEFAULT_IP_VERSION_SETTING, insecureRandom, ipVersionSetting, LOGGER, random

Constructor Summary

Constructors

Constructor and Description
ReliableDnsClient()
ReliableDnsClient(DnsCache dnsCache)

Method Summary

Modifier and Type	Method and Description
protected String	isResponseAcceptable(DnsMessage response) Check if the response from the system's nameserver is acceptable.
protected boolean	isResponseCacheable(Question q, DnsMessage dnsMessage) Whether a response from the DNS system should be cached or not.
protected DnsMessage.Builder	newQuestion(DnsMessage.Builder questionMessage)
protected DnsMessage	query(DnsMessage.Builder q) Send a query request to the DNS system.
void	setDataSource(DnsDataSource dataSource) Set a DnsDataSource to be used by the DnsClient.
void	setMode(ReliableDnsClient.Mode mode) Set the mode used when resolving queries.

Methods inherited from class org.minidns.AbstractDnsClient

getCache, getCachedIPv4AddressesFor, getCachedIPv4NameserverAddressesFor, getCachedIPv6AddressesFor, getCachedIPv6NameserverAddressesFor, getCachedNameserverRecordsFor, getDataSource, getPreferedIpVersion, getQueryFor, query, query, query, query, query, query, query, query, query, query, query, queryAsync, queryAsync, queryAsync, queryAsync, queryAsync, setDefaultIpVersion, setPreferedIpVersion

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ReliableDnsClient

public ReliableDnsClient(DnsCache dnsCache)

ReliableDnsClient

public ReliableDnsClient()

Method Detail

query

protected DnsMessage query(DnsMessage.Builder q)
                    throws IOException

Description copied from class: AbstractDnsClient

Send a query request to the DNS system.

Specified by:

query in class AbstractDnsClient

Parameters:

q - The query to send to the server.

Returns:

The response (or null).

Throws:

IOException - if an IO error occurs.

newQuestion

protected DnsMessage.Builder newQuestion(DnsMessage.Builder questionMessage)

Specified by:

newQuestion in class AbstractDnsClient

isResponseCacheable

protected boolean isResponseCacheable(Question q,
                                      DnsMessage dnsMessage)

Description copied from class: AbstractDnsClient

Whether a response from the DNS system should be cached or not.

Overrides:

isResponseCacheable in class AbstractDnsClient

Parameters:

q - The question the response message should answer.

dnsMessage - The response message received using the DNS client.

Returns:

True, if the response should be cached, false otherwise.

isResponseAcceptable

protected String isResponseAcceptable(DnsMessage response)

Check if the response from the system's nameserver is acceptable. Must return null if the response is acceptable, or a String describing why it is not acceptable. If the response is not acceptable then ReliableDnsClient will fall back to resolve the query iteratively.

Parameters:

response - the response we got from the system's nameserver.

Returns:

null if the response is acceptable, or a String if not.

setDataSource

public void setDataSource(DnsDataSource dataSource)

Description copied from class: AbstractDnsClient

Set a DnsDataSource to be used by the DnsClient. The default implementation will direct all queries directly to the Internet. This can be used to define a non-default handling for outgoing data. This can be useful to redirect the requests to a proxy or to modify requests after or responses before they are handled by the DnsClient implementation.

Overrides:

setDataSource in class AbstractDnsClient

Parameters:

dataSource - An implementation of DNSDataSource that shall be used.

setMode

public void setMode(ReliableDnsClient.Mode mode)

Set the mode used when resolving queries.

Parameters:

mode - the mode to use.