org.apache.james.dnsserver
Class DNSServer

java.lang.Object
  org.apache.avalon.framework.logger.AbstractLogEnabled
      org.apache.james.dnsserver.DNSServer

All Implemented Interfaces:

org.apache.avalon.framework.activity.Initializable, org.apache.avalon.framework.configuration.Configurable, org.apache.avalon.framework.logger.LogEnabled, DNSService, DNSServerMBean

public class DNSServer
extends org.apache.avalon.framework.logger.AbstractLogEnabled
implements org.apache.avalon.framework.configuration.Configurable, org.apache.avalon.framework.activity.Initializable, DNSService, DNSServerMBean

Provides DNS client functionality to services running inside James

Field Summary

protected org.xbill.DNS.Cache	cache A TTL cache of results received from the DNS server.
protected org.xbill.DNS.Resolver	resolver A resolver instance used to retrieve DNS records.

Fields inherited from interface org.apache.james.api.dnsservice.DNSService

ROLE

Constructor Summary

DNSServer()

Method Summary

void	configure(org.apache.avalon.framework.configuration.Configuration configuration)
java.util.Collection	findMXRecords(java.lang.String hostname) Return a prioritized unmodifiable list of host handling mail for the domain.
java.util.Collection	findTXTRecords(java.lang.String hostname) Get a collection of DNS TXT Records
java.net.InetAddress[]	getAllByName(java.lang.String host)
java.net.InetAddress	getByName(java.lang.String host)
java.lang.String[]	getDNSServers() Return the list of DNS servers in use by this service
java.lang.String	getHostName(java.net.InetAddress addr)
java.net.InetAddress	getLocalHost()
org.xbill.DNS.Name[]	getSearchPaths() Return the list of DNS servers in use by this service
java.util.Iterator	getSMTPHostAddresses(java.lang.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.
void	initialize()
protected org.xbill.DNS.Record[]	lookup(java.lang.String namestr, int type, java.lang.String typeDesc) Looks up DNS records of the specified type for the specified name.
protected org.xbill.DNS.Record[]	lookupNoException(java.lang.String namestr, int type, java.lang.String typeDesc)

Methods inherited from class org.apache.avalon.framework.logger.AbstractLogEnabled

enableLogging, getLogger, setupLogger, setupLogger, setupLogger

Methods inherited from class java.lang.Object

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

Field Detail

resolver

protected org.xbill.DNS.Resolver resolver

A resolver instance used to retrieve DNS records. This is a reference to a third party library object.

cache

protected org.xbill.DNS.Cache cache

A TTL cache of results received from the DNS server. This is a reference to a third party library object.

Constructor Detail

DNSServer

public DNSServer()

Method Detail

configure

public void configure(org.apache.avalon.framework.configuration.Configuration configuration)
               throws org.apache.avalon.framework.configuration.ConfigurationException

Specified by:

configure in interface org.apache.avalon.framework.configuration.Configurable

Throws:

org.apache.avalon.framework.configuration.ConfigurationException

See Also:

Configurable.configure(Configuration)

initialize

public void initialize()
                throws java.lang.Exception

Specified by:

initialize in interface org.apache.avalon.framework.activity.Initializable

Throws:

java.lang.Exception

See Also:

Initializable.initialize()

getDNSServers

public java.lang.String[] getDNSServers()

Return the list of DNS servers in use by this service

Specified by:

getDNSServers in interface DNSServerMBean

Returns:

an array of DNS server names

getSearchPaths

public org.xbill.DNS.Name[] getSearchPaths()

Return the list of DNS servers in use by this service

Returns:

an array of DNS server names

findMXRecords

public java.util.Collection findMXRecords(java.lang.String hostname)
                                   throws TemporaryResolutionException

Description copied from interface: DNSService

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

Specified by:

findMXRecords in interface DNSService

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

See Also:

DNSService.findMXRecords(String)

lookup

protected org.xbill.DNS.Record[] lookup(java.lang.String namestr,
                                        int type,
                                        java.lang.String typeDesc)
                                 throws TemporaryResolutionException

Looks up DNS records of the specified type for the specified name. This method is a public wrapper for the private implementation method

Parameters:

namestr - the name of the host to be looked up

type - the type of record desired

typeDesc - the description of the record type, for debugging purpose

Throws:

TemporaryResolutionException

lookupNoException

protected org.xbill.DNS.Record[] lookupNoException(java.lang.String namestr,
                                                   int type,
                                                   java.lang.String typeDesc)

getSMTPHostAddresses

public java.util.Iterator getSMTPHostAddresses(java.lang.String domainName)
                                        throws TemporaryResolutionException

Description copied from interface: DNSService

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.

Specified by:

getSMTPHostAddresses in interface DNSService

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

See Also:

DNSService.getSMTPHostAddresses(String)

getByName

public java.net.InetAddress getByName(java.lang.String host)
                               throws java.net.UnknownHostException

Specified by:

getByName in interface DNSService

Throws:

java.net.UnknownHostException

See Also:

DNSService.getByName(String)

getAllByName

public java.net.InetAddress[] getAllByName(java.lang.String host)
                                    throws java.net.UnknownHostException

Specified by:

getAllByName in interface DNSService

Throws:

java.net.UnknownHostException

See Also:

DNSService.getAllByName(String)

findTXTRecords

public java.util.Collection findTXTRecords(java.lang.String hostname)

Description copied from interface: DNSService

Get a collection of DNS TXT Records

Specified by:

findTXTRecords in interface DNSService

Parameters:

hostname - The hostname to check

Returns:

collection of strings representing TXT record values

See Also:

DNSService.findTXTRecords(String)

getHostName

public java.lang.String getHostName(java.net.InetAddress addr)

Specified by:

getHostName in interface DNSService

See Also:

DNSService.getHostName(java.net.InetAddress)

getLocalHost

public java.net.InetAddress getLocalHost()
                                  throws java.net.UnknownHostException

Specified by:

getLocalHost in interface DNSService

Throws:

java.net.UnknownHostException

See Also:

DNSService.getLocalHost()