Package org.xbill.DNS.lookup

Class LookupSession

java.lang.Object

org.xbill.DNS.lookup.LookupSession

public class LookupSession
extends Object

LookupSession provides facilities to make DNS Queries. A LookupSession is intended to be long lived, and it's behaviour can be configured using the properties of the LookupSession.LookupSessionBuilder instance returned by builder().

Since:

3.4

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	LookupSession.LookupSessionBuilder	A builder for LookupSession instances.

Field Summary

Fields

Modifier and Type	Field	Description
private final Map<Integer,Cache>	caches
private final boolean	cycleResults
static final int	DEFAULT_MAX_ITERATIONS
static final int	DEFAULT_NDOTS
private final Executor	executor
private final HostsFileParser	hostsFileParser
private final IrrelevantRecordMode	irrelevantRecordMode
private final int	maxRedirects
private final int	ndots
private final Resolver	resolver
private final List<Name>	searchPath

Constructor Summary

Constructors

Modifier	Constructor	Description
private	LookupSession(@NonNull Resolver resolver, int maxRedirects, int ndots, List<Name> searchPath, boolean cycleResults, List<Cache> caches, HostsFileParser hostsFileParser, Executor executor, IrrelevantRecordMode irrelevantRecordMode)

Method Summary

Modifier and Type	Method	Description
static LookupSession.LookupSessionBuilder	builder()	Returns an empty LookupSession.LookupSessionBuilder instance.
private static LookupResult	buildResult(Message answer, List<Name> aliases, Record query)	Returns a LookupResult if this response was a non-exceptional empty result, throws otherwise.
private <T extends Throwable, R> CompletionStage<R>	completeExceptionally(T failure)
static LookupSession.LookupSessionBuilder	defaultBuilder()	Returns a LookupSession.LookupSessionBuilder instance initialized with defaults.
(package private) List<Name>	expandName(Name name)	Generate a stream of names according to the search path application semantics.
(package private) Cache	getCache(int dclass)
CompletionStage<LookupResult>	lookupAsync(Name name, int type)	Make an asynchronous lookup of the provided name using the default DClass.IN.
CompletionStage<LookupResult>	lookupAsync(Name name, int type, int dclass)	Make an asynchronous lookup of the provided name.
CompletionStage<LookupResult>	lookupAsync(Record question)	Make an asynchronous lookup with the provided Record.
private CompletionStage<LookupResult>	lookupUntilSuccess(Iterator<Name> names, int type, int dclass)
private CompletionStage<LookupResult>	lookupWithCache(Record queryRecord, List<Name> aliases)
private LookupResult	lookupWithHosts(List<Name> names, int type)
private CompletionStage<LookupResult>	lookupWithResolver(Record queryRecord, List<Name> aliases)
private Message	maybeAddToCache(Message message)
private CompletionStage<LookupResult>	maybeFollowRedirect(LookupResult response, Record query, int redirectCount)
private CompletionStage<LookupResult>	maybeFollowRedirectsInAnswer(LookupResult response, Record query, int redirectCount)
private CompletionStage<LookupResult>	resolveRedirects(LookupResult response, Record query)
private static Name	safeConcat(Name name, Name suffix)
private CompletionStage<LookupResult>	setResponseToMessageFuture(SetResponse setResponse, Record queryRecord, List<Name> aliases)

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT_MAX_ITERATIONS

public static final int DEFAULT_MAX_ITERATIONS

See Also:

• Constant Field Values

DEFAULT_NDOTS

public static final int DEFAULT_NDOTS

See Also:

• Constant Field Values

resolver

private final Resolver resolver

maxRedirects

private final int maxRedirects

ndots

private final int ndots

searchPath

private final List<Name> searchPath

cycleResults

private final boolean cycleResults

caches

private final Map<Integer,Cache> caches

hostsFileParser

private final HostsFileParser hostsFileParser

executor

private final Executor executor

irrelevantRecordMode

private final IrrelevantRecordMode irrelevantRecordMode

Constructor Details

LookupSession

private LookupSession(@NonNull
 @NonNull Resolver resolver,
 int maxRedirects,
 int ndots,
 List<Name> searchPath,
 boolean cycleResults,
 List<Cache> caches,
 HostsFileParser hostsFileParser,
 Executor executor,
 IrrelevantRecordMode irrelevantRecordMode)

Method Details

builder

public static LookupSession.LookupSessionBuilder builder()

Returns an empty LookupSession.LookupSessionBuilder instance. See defaultBuilder() for a builder initialized with defaults.

defaultBuilder

public static LookupSession.LookupSessionBuilder defaultBuilder()

Returns a LookupSession.LookupSessionBuilder instance initialized with defaults.

• Resolver: an ExtendedResolver initialized with the system's default DNS servers as determined by ResolverConfig.
• ndots: as determined by ResolverConfig.
• Cache: A cache for the IN class is installed.
• Hosts: The local host database file is used.

getCache

Cache getCache(int dclass)

lookupAsync

public CompletionStage<LookupResult> lookupAsync(Record question)

Make an asynchronous lookup with the provided Record.

Parameters:

question - the name, type and DClass to look up.

Returns:

A CompletionStage what will yield the eventual lookup result.

Since:

3.6

lookupAsync

public CompletionStage<LookupResult> lookupAsync(Name name,
 int type)

Make an asynchronous lookup of the provided name using the default DClass.IN.

Parameters:

name - the name to look up.

type - the type to look up, values should correspond to constants in Type.

Returns:

A CompletionStage what will yield the eventual lookup result.

lookupAsync

public CompletionStage<LookupResult> lookupAsync(Name name,
 int type,
 int dclass)

Make an asynchronous lookup of the provided name.

Parameters:

name - the name to look up.

type - the type to look up, values should correspond to constants in Type.

dclass - the class to look up, values should correspond to constants in DClass.

Returns:

A CompletionStage what will yield the eventual lookup result.

expandName

List<Name> expandName(Name name)

Generate a stream of names according to the search path application semantics. The semantics of this is a bit odd, but they are inherited from Lookup. Note that the stream returned is never empty, as it will at the very least always contain name.

safeConcat

private static Name safeConcat(Name name,
 Name suffix)

lookupWithHosts

private LookupResult lookupWithHosts(List<Name> names,
 int type)

lookupUntilSuccess

private CompletionStage<LookupResult> lookupUntilSuccess(Iterator<Name> names,
 int type,
 int dclass)

lookupWithCache

private CompletionStage<LookupResult> lookupWithCache(Record queryRecord,
 List<Name> aliases)

lookupWithResolver

private CompletionStage<LookupResult> lookupWithResolver(Record queryRecord,
 List<Name> aliases)

maybeAddToCache

private Message maybeAddToCache(Message message)

setResponseToMessageFuture

private CompletionStage<LookupResult> setResponseToMessageFuture(SetResponse setResponse,
 Record queryRecord,
 List<Name> aliases)

completeExceptionally

private <T extends Throwable,
R> CompletionStage<R> completeExceptionally(T failure)

resolveRedirects

private CompletionStage<LookupResult> resolveRedirects(LookupResult response,
 Record query)

maybeFollowRedirect

private CompletionStage<LookupResult> maybeFollowRedirect(LookupResult response,
 Record query,
 int redirectCount)

maybeFollowRedirectsInAnswer

private CompletionStage<LookupResult> maybeFollowRedirectsInAnswer(LookupResult response,
 Record query,
 int redirectCount)

buildResult

private static LookupResult buildResult(Message answer,
 List<Name> aliases,
 Record query)

Returns a LookupResult if this response was a non-exceptional empty result, throws otherwise.