org.apache.james.protocols.smtp
Interface DNSService

public interface DNSService

Provides abstraction for DNS resolutions. The interface is Mail specific. It may be a good idea to make the interface more generic or expose commonly needed DNS methods.

Field Summary

static String

ROLE The component role used by components implementing this service

Method Summary

Collection<String>	findMXRecords(String hostname) Return a prioritized unmodifiable list of host handling mail for the domain.
Collection<String>	findTXTRecords(String hostname) Get a collection of DNS TXT Records
InetAddress[]	getAllByName(String host)
InetAddress	getByName(String host)
String	getHostName(InetAddress addr) Determines the hostname for an address
InetAddress	getLocalHost() get the local hosts InetAddress
Iterator<org.apache.mailet.HostAddress>	getSMTPHostAddresses(String domainName) Returns an Iterator over org.apache.mailet.HostAddress, a specialized subclass of javax.mail.URLName, which provides location information for servers that are specified as mail handlers for the given hostname.

Field Detail

ROLE

static final String ROLE

The component role used by components implementing this service

See Also:

Constant Field Values

Method Detail

findMXRecords

Collection<String> findMXRecords(String hostname)
                                 throws TemporaryResolutionException

Return a prioritized unmodifiable list of host handling mail for the domain.

First lookup MX hosts, then MX hosts of the CNAME adress, and if no server is found return the IP of the hostname

Parameters:

hostname - domain name to look up

Returns:

a unmodifiable list of handling servers corresponding to this mail domain name

Throws:

TemporaryResolutionException - get thrown on temporary problems

findTXTRecords

Collection<String> findTXTRecords(String hostname)

Get a collection of DNS TXT Records

Parameters:

hostname - The hostname to check

Returns:

collection of strings representing TXT record values

getSMTPHostAddresses

Iterator<org.apache.mailet.HostAddress> getSMTPHostAddresses(String domainName)
                                                             throws TemporaryResolutionException

Returns an Iterator over org.apache.mailet.HostAddress, a specialized subclass of javax.mail.URLName, which provides location information for servers that are specified as mail handlers for the given hostname. This is done using MX records, and the HostAddress instances are returned sorted by MX priority. If no host is found for domainName, the Iterator returned will be empty and the first call to hasNext() will return false. The Iterator is a nested iterator: the outer iteration is over the results of the MX record lookup, and the inner iteration is over potentially multiple A records for each MX record. DNS lookups are deferred until actually needed.

Parameters:

domainName - - the domain for which to find mail servers

Returns:

an Iterator over HostAddress instances, sorted by priority

Throws:

TemporaryResolutionException - get thrown on temporary problems

Since:

v2.2.0a16-unstable

getAllByName

InetAddress[] getAllByName(String host)
                           throws UnknownHostException

Throws:

UnknownHostException

See Also:

InetAddress.getAllByName(String)

getByName

InetAddress getByName(String host)
                      throws UnknownHostException

Throws:

UnknownHostException

See Also:

InetAddress.getByName(String)

getHostName

String getHostName(InetAddress addr)

Determines the hostname for an address

Parameters:

addr - the address record

Returns:

the hostname defined in the address record

getLocalHost

InetAddress getLocalHost()
                         throws UnknownHostException

get the local hosts InetAddress

Returns:

the localhosts inet address

Throws:

UnknownHostException