Class AbstractDnsClient

java.lang.Object

org.minidns.AbstractDnsClient

Direct Known Subclasses:

DnsClient, IterativeDnsClient, ReliableDnsClient

public abstract class AbstractDnsClient
extends Object

A minimal DNS client for SRV/A/AAAA/NS and CNAME lookups, with IDN support. This circumvents the missing javax.naming package on android.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	AbstractDnsClient.IpVersionSetting

Field Summary

Fields

Modifier and Type	Field	Description
protected final DnsCache	cache	The internal DNS cache.
protected DnsDataSource	dataSource
protected static final LruCache	DEFAULT_CACHE
protected static AbstractDnsClient.IpVersionSetting	DEFAULT_IP_VERSION_SETTING
protected final Random	insecureRandom
protected AbstractDnsClient.IpVersionSetting	ipVersionSetting
protected static final Logger	LOGGER
protected final Random	random	The internal random class for sequence generation.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractDnsClient()	Create a new DNS client using the global default cache.
protected	AbstractDnsClient(DnsCache cache)	Create a new DNS client with the given DNS cache.

Method Summary

Modifier and Type	Method	Description
DnsCache	getCache()	Get the cache used by this DNS client.
Set<A>	getCachedIPv4AddressesFor(DnsName dnsName)
Set<A>	getCachedIPv4NameserverAddressesFor(DnsName dnsName)
Set<AAAA>	getCachedIPv6AddressesFor(DnsName dnsName)
Set<AAAA>	getCachedIPv6NameserverAddressesFor(DnsName dnsName)
Set<NS>	getCachedNameserverRecordsFor(DnsName dnsName)
DnsDataSource	getDataSource()	Returns the currently used DnsDataSource.
AbstractDnsClient.IpVersionSetting	getPreferedIpVersion()
protected DnsMessage	getQueryFor(Question q)
protected boolean	isResponseCacheable(Question q, DnsQueryResult result)	Whether a response from the DNS system should be cached or not.
protected abstract DnsMessage.Builder	newQuestion(DnsMessage.Builder questionMessage)
final DnsQueryResult	query(CharSequence name, Record.TYPE type)	Query the system nameservers for a single entry of the class IN (which is used for MX, SRV, A, AAAA and most other RRs).
DnsQueryResult	query(String name, Record.TYPE type, InetAddress address)	Query a nameserver for a single entry of class IN.
final DnsQueryResult	query(String name, Record.TYPE type, Record.CLASS clazz)	Query the system nameservers for a single entry of any class.
DnsQueryResult	query(String name, Record.TYPE type, Record.CLASS clazz, InetAddress address)	Query a nameserver for a single entry.
DnsQueryResult	query(String name, Record.TYPE type, Record.CLASS clazz, InetAddress address, int port)	Query a nameserver for a single entry.
protected abstract DnsQueryResult	query(DnsMessage.Builder query)	Send a query request to the DNS system.
final DnsQueryResult	query(DnsMessage query, InetAddress host)
final DnsQueryResult	query(DnsMessage requestMessage, InetAddress address, int port)
DnsQueryResult	query(Question q)
DnsQueryResult	query(Question q, InetAddress address)	Query a specific server for one entry.
final DnsQueryResult	query(Question q, InetAddress server, int port)
final DnsQueryResult	query(DnsName name, Record.TYPE type)	Query the system nameservers for a single entry of the class IN (which is used for MX, SRV, A, AAAA and most other RRs).
final MiniDnsFuture<DnsQueryResult, IOException>	queryAsync(CharSequence name, Record.TYPE type)
protected MiniDnsFuture<DnsQueryResult, IOException>	queryAsync(DnsMessage.Builder query)	Default implementation of an asynchronous DNS query which just wraps the synchronous case.
final MiniDnsFuture<DnsQueryResult, IOException>	queryAsync(DnsMessage query, InetAddress dnsServer)
final MiniDnsFuture<DnsQueryResult, IOException>	queryAsync(DnsMessage requestMessage, InetAddress address, int port)
final MiniDnsFuture<DnsQueryResult, IOException>	queryAsync(Question q)
void	setDataSource(DnsDataSource dataSource)	Set a DnsDataSource to be used by the DnsClient.
static void	setDefaultIpVersion(AbstractDnsClient.IpVersionSetting preferedIpVersion)
void	setPreferedIpVersion(AbstractDnsClient.IpVersionSetting preferedIpVersion)

Methods inherited from class Object

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

Field Details

DEFAULT_CACHE

protected static final LruCache DEFAULT_CACHE

LOGGER

protected static final Logger LOGGER

random

protected final Random random

The internal random class for sequence generation.

insecureRandom

protected final Random insecureRandom

cache

protected final DnsCache cache

The internal DNS cache.

dataSource

protected DnsDataSource dataSource

DEFAULT_IP_VERSION_SETTING

protected static AbstractDnsClient.IpVersionSetting DEFAULT_IP_VERSION_SETTING

ipVersionSetting

protected AbstractDnsClient.IpVersionSetting ipVersionSetting

Constructor Details

AbstractDnsClient

protected AbstractDnsClient(DnsCache cache)

Create a new DNS client with the given DNS cache.

Parameters:

cache - The backend DNS cache.

AbstractDnsClient

protected AbstractDnsClient()

Create a new DNS client using the global default cache.

Method Details

setDefaultIpVersion

public static void setDefaultIpVersion(AbstractDnsClient.IpVersionSetting preferedIpVersion)

setPreferedIpVersion

public void setPreferedIpVersion(AbstractDnsClient.IpVersionSetting preferedIpVersion)

getPreferedIpVersion

public AbstractDnsClient.IpVersionSetting getPreferedIpVersion()

query

public final DnsQueryResult query(String name,
 Record.TYPE type,
 Record.CLASS clazz)
                           throws IOException

Query the system nameservers for a single entry of any class. This can be used to determine the name server version, if name is version.bind, type is TYPE.TXT and clazz is CLASS.CH.

Parameters:

name - The DNS name to request.

type - The DNS type to request (SRV, A, AAAA, ...).

clazz - The class of the request (usually IN for Internet).

Returns:

The response (or null on timeout/error).

Throws:

IOException - if an IO error occurs.

query

public final DnsQueryResult query(DnsName name,
 Record.TYPE type)
                           throws IOException

Query the system nameservers for a single entry of the class IN (which is used for MX, SRV, A, AAAA and most other RRs).

Parameters:

name - The DNS name to request.

type - The DNS type to request (SRV, A, AAAA, ...).

Returns:

The response (or null on timeout/error).

Throws:

IOException - if an IO error occurs.

query

public final DnsQueryResult query(CharSequence name,
 Record.TYPE type)
                           throws IOException

Query the system nameservers for a single entry of the class IN (which is used for MX, SRV, A, AAAA and most other RRs).

Parameters:

name - The DNS name to request.

type - The DNS type to request (SRV, A, AAAA, ...).

Returns:

The response (or null on timeout/error).

Throws:

IOException - if an IO error occurs.

query

public DnsQueryResult query(Question q)
                     throws IOException

Throws:

IOException

query

protected abstract DnsQueryResult query(DnsMessage.Builder query)
                                 throws IOException

Send a query request to the DNS system.

Parameters:

query - The query to send to the server.

Returns:

The response (or null).

Throws:

IOException - if an IO error occurs.

queryAsync

public final MiniDnsFuture<DnsQueryResult, IOException> queryAsync(CharSequence name,
 Record.TYPE type)

queryAsync

public final MiniDnsFuture<DnsQueryResult, IOException> queryAsync(Question q)

queryAsync

protected MiniDnsFuture<DnsQueryResult, IOException> queryAsync(DnsMessage.Builder query)

Default implementation of an asynchronous DNS query which just wraps the synchronous case.

Subclasses override this method to support true asynchronous queries.

Parameters:

query - the query.

Returns:

a future for this query.

query

public final DnsQueryResult query(Question q,
 InetAddress server,
 int port)
                           throws IOException

Throws:

IOException

query

public final DnsQueryResult query(DnsMessage requestMessage,
 InetAddress address,
 int port)
                           throws IOException

Throws:

IOException

queryAsync

public final MiniDnsFuture<DnsQueryResult, IOException> queryAsync(DnsMessage requestMessage,
 InetAddress address,
 int port)

isResponseCacheable

protected boolean isResponseCacheable(Question q,
 DnsQueryResult result)

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

Parameters:

q - The question the response message should answer.

result - The DNS query result.

Returns:

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

newQuestion

protected abstract DnsMessage.Builder newQuestion(DnsMessage.Builder questionMessage)

query

public DnsQueryResult query(String name,
 Record.TYPE type,
 Record.CLASS clazz,
 InetAddress address,
 int port)
                     throws IOException

Query a nameserver for a single entry.

Parameters:

name - The DNS name to request.

type - The DNS type to request (SRV, A, AAAA, ...).

clazz - The class of the request (usually IN for Internet).

address - The DNS server address.

port - The DNS server port.

Returns:

The response (or null on timeout / failure).

Throws:

IOException - On IO Errors.

query

public DnsQueryResult query(String name,
 Record.TYPE type,
 Record.CLASS clazz,
 InetAddress address)
                     throws IOException

Query a nameserver for a single entry.

Parameters:

name - The DNS name to request.

type - The DNS type to request (SRV, A, AAAA, ...).

clazz - The class of the request (usually IN for Internet).

address - The DNS server host.

Returns:

The response (or null on timeout / failure).

Throws:

IOException - On IO Errors.

query

public DnsQueryResult query(String name,
 Record.TYPE type,
 InetAddress address)
                     throws IOException

Query a nameserver for a single entry of class IN.

Parameters:

name - The DNS name to request.

type - The DNS type to request (SRV, A, AAAA, ...).

address - The DNS server host.

Returns:

The response (or null on timeout / failure).

Throws:

IOException - On IO Errors.

query

public final DnsQueryResult query(DnsMessage query,
 InetAddress host)
                           throws IOException

Throws:

IOException

query

public DnsQueryResult query(Question q,
 InetAddress address)
                     throws IOException

Query a specific server for one entry.

Parameters:

q - The question section of the DNS query.

address - The dns server address.

Returns:

The a DNS query result.

Throws:

IOException - On IOErrors.

queryAsync

public final MiniDnsFuture<DnsQueryResult, IOException> queryAsync(DnsMessage query,
 InetAddress dnsServer)

getDataSource

public DnsDataSource getDataSource()

Returns the currently used DnsDataSource. See setDataSource(DnsDataSource) for details.

Returns:

The currently used DnsDataSource

setDataSource

public void setDataSource(DnsDataSource dataSource)

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.

Parameters:

dataSource - An implementation of DNSDataSource that shall be used.

getCache

public DnsCache getCache()

Get the cache used by this DNS client.

Returns:

the cached used by this DNS client or null.

getQueryFor

protected DnsMessage getQueryFor(Question q)

getCachedNameserverRecordsFor

public Set<NS> getCachedNameserverRecordsFor(DnsName dnsName)

getCachedIPv4AddressesFor

public Set<A> getCachedIPv4AddressesFor(DnsName dnsName)

getCachedIPv6AddressesFor

public Set<AAAA> getCachedIPv6AddressesFor(DnsName dnsName)

getCachedIPv4NameserverAddressesFor

public Set<A> getCachedIPv4NameserverAddressesFor(DnsName dnsName)

getCachedIPv6NameserverAddressesFor

public Set<AAAA> getCachedIPv6NameserverAddressesFor(DnsName dnsName)