Package org.ldaptive

Class DnsSrvConnectionStrategy

java.lang.Object

org.ldaptive.AbstractFreezable

org.ldaptive.AbstractConnectionStrategy

org.ldaptive.DnsSrvConnectionStrategy

All Implemented Interfaces:

Iterable<LdapURL>, ConnectionStrategy, Freezable

public class DnsSrvConnectionStrategy
extends AbstractConnectionStrategy

DNS SRV connection strategy. Queries a DNS server for SRV records and uses those records to construct a list of URLs. A time to live can be set to control how often the DNS server is consulted. See http://www.ietf.org/rfc/rfc2782.txt.

Nested Class Summary

Nested classes/interfaces inherited from class org.ldaptive.AbstractConnectionStrategy

AbstractConnectionStrategy.DefaultLdapURLIterator

Field Summary

Fields

Modifier and Type	Field	Description
protected static Duration	DEFAULT_TTL	Default time to live for DNS results.
private DNSContextFactory	dnsContextFactory	DNS context factory to override initialization parameters.
private Map<SRVDNSResolver,String>	dnsResolvers	Resolver(s) for SRV DNS records.
private Instant	expirationTime	SRV records expiration time.
private String	ldapUrls	LDAP URL string used to initialize this strategy.
private Duration	srvTtl	Time to live for SRV records.
private boolean	useSSL	Connect to LDAP using LDAPS.

Fields inherited from class org.ldaptive.AbstractConnectionStrategy

ldapURLSet, logger

Constructor Summary

Constructors

Constructor	Description
DnsSrvConnectionStrategy()	Default constructor.
DnsSrvConnectionStrategy(Duration ttl)	Creates a new DNS SRV connection strategy.
DnsSrvConnectionStrategy(DNSContextFactory factory)	Creates a new DNS SRV connection strategy.
DnsSrvConnectionStrategy(DNSContextFactory factory, Duration ttl)	Creates a new DNS SRV connection strategy.
DnsSrvConnectionStrategy(DNSContextFactory factory, Duration ttl, boolean ssl)	Creates a new DNS SRV connection strategy.

Method Summary

Modifier and Type	Method	Description
Iterator<LdapURL>	iterator()	Returns a list of URLs retrieved from DNS SRV records.
DnsSrvConnectionStrategy	newInstance()	Create a deep copy of this strategy.
protected String[]	parseDnsUrl(String url)	Parses a DNS URL of the form dns://hostname/domain?
protected String[]	parseUrl(String url)	Parses the supplied URL.
void	populate(String urls, LdapURLSet urlSet)	Populates a LdapURLSet from the URL string provided at configuration time.
protected Set<SRVRecord>	readSrvRecords(String urls)	Parses the supplied DNS URL string and reads SRV records from DNS.
protected Set<SRVRecord>	retrieveDNSRecords()	Invoke DNSResolver.resolve(String) for each resolver until results are found.

Methods inherited from class org.ldaptive.AbstractConnectionStrategy

failure, getActivateCondition, getRetryCondition, initialize, isInitialized, setRetryCondition, success, toString

Methods inherited from class org.ldaptive.AbstractFreezable

assertMutable, freeze, freeze, freeze, isFrozen

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

DEFAULT_TTL

protected static final Duration DEFAULT_TTL

Default time to live for DNS results.

dnsContextFactory

private final DNSContextFactory dnsContextFactory

DNS context factory to override initialization parameters.

srvTtl

private final Duration srvTtl

Time to live for SRV records.

useSSL

private final boolean useSSL

Connect to LDAP using LDAPS.

ldapUrls

private String ldapUrls

LDAP URL string used to initialize this strategy.

dnsResolvers

private Map<SRVDNSResolver,String> dnsResolvers

Resolver(s) for SRV DNS records.

expirationTime

private Instant expirationTime

SRV records expiration time.

Constructor Detail

DnsSrvConnectionStrategy

public DnsSrvConnectionStrategy()

Default constructor.

DnsSrvConnectionStrategy

public DnsSrvConnectionStrategy(Duration ttl)

Creates a new DNS SRV connection strategy.

Parameters:

ttl - time to live for SRV records

DnsSrvConnectionStrategy

public DnsSrvConnectionStrategy(DNSContextFactory factory)

Creates a new DNS SRV connection strategy.

Parameters:

factory - DNS context factory

DnsSrvConnectionStrategy

public DnsSrvConnectionStrategy(DNSContextFactory factory,
                                Duration ttl)

Creates a new DNS SRV connection strategy.

Parameters:

factory - DNS context factory

ttl - time to live for SRV records

DnsSrvConnectionStrategy

public DnsSrvConnectionStrategy(DNSContextFactory factory,
                                Duration ttl,
                                boolean ssl)

Creates a new DNS SRV connection strategy.

Parameters:

factory - DNS context factory

ttl - time to live for SRV records

ssl - whether SRV records should produce LDAPS URLs

Method Detail

populate

public void populate(String urls,
                     LdapURLSet urlSet)

Description copied from interface: ConnectionStrategy

Populates a LdapURLSet from the URL string provided at configuration time.

Specified by:

populate in interface ConnectionStrategy

Overrides:

populate in class AbstractConnectionStrategy

Parameters:

urls - Space-delimited string of URLs describing the LDAP hosts to connect to. The URLs in the string are commonly ldap:// or ldaps:// URLs that directly describe the hosts to connect to, but may also describe a resource from which to obtain LDAP connection URLs as is the case for DnsSrvConnectionStrategy that use URLs with the scheme dns:.

urlSet - LDAP URL set to populate.

readSrvRecords

protected Set<SRVRecord> readSrvRecords(String urls)

Parses the supplied DNS URL string and reads SRV records from DNS.

Parameters:

urls - to parse

Returns:

Set of DNS SRV records ordered first by priority and then by weight.

parseUrl

protected String[] parseUrl(String url)

Parses the supplied URL. If the URL has an ldap scheme, it is inspected for a baseDN which will be used as the domain. Otherwise, the URL is assumed to have a dns scheme.

Parameters:

url - to parse

Returns:

array containing the DNS URL and the record name in that order

parseDnsUrl

protected String[] parseDnsUrl(String url)

Parses a DNS URL of the form dns://hostname/domain?record. Where record is the DNS record to retrieve.

Parameters:

url - to parse

Returns:

array containing the DNS URL and the record name in that order

iterator

public Iterator<LdapURL> iterator()

Returns a list of URLs retrieved from DNS SRV records.

Returns:

list of URLs to attempt connections to

retrieveDNSRecords

protected Set<SRVRecord> retrieveDNSRecords()

Invoke DNSResolver.resolve(String) for each resolver until results are found.

Returns:

set of LDAP URLs

newInstance

public DnsSrvConnectionStrategy newInstance()

Description copied from interface: ConnectionStrategy

Create a deep copy of this strategy.

Returns:

new instance of this connection strategy