io.netty.resolver.dns

Class DnsNameResolverBuilder<T extends DnsNameResolverBuilder<T>>

java.lang.Object

io.netty.resolver.dns.DnsNameResolverBuilder<T>

Direct Known Subclasses:

DefaultDnsNameResolverBuilder

public abstract class DnsNameResolverBuilder<T extends DnsNameResolverBuilder<T>>
extends Object

A DnsNameResolver builder.

Field Summary

Fields

Modifier and Type	Field and Description
protected io.netty.bootstrap.ChannelFactory<? extends io.netty.channel.socket.DatagramChannel>	channelFactory
protected io.netty.channel.EventLoop	eventLoop
protected HostsFileEntriesResolver	hostsFileEntriesResolver
protected InetSocketAddress	localAddress
protected int	maxPayloadSize
protected int	maxQueriesPerResolve
protected Integer	maxTtl
protected Integer	minTtl
protected DnsServerAddresses	nameServerAddresses
protected Integer	negativeTtl
protected boolean	optResourceEnabled
protected long	queryTimeoutMillis
protected boolean	recursionDesired
protected DnsCache	resolveCache
protected io.netty.channel.socket.InternetProtocolFamily[]	resolvedAddressTypes
protected boolean	traceEnabled

Constructor Summary

Constructors

Constructor and Description
DnsNameResolverBuilder(io.netty.channel.EventLoop eventLoop) Creates a new builder.

Method Summary

Modifier and Type	Method and Description
DnsNameResolver	build() Returns a new DnsNameResolver instance.
protected abstract DnsNameResolver	build0(DnsCache cache)
T	channelFactory(io.netty.bootstrap.ChannelFactory<? extends io.netty.channel.socket.DatagramChannel> channelFactory) Sets the ChannelFactory that will create a DatagramChannel.
T	channelType(Class<? extends io.netty.channel.socket.DatagramChannel> channelType) Sets the ChannelFactory as a ReflectiveChannelFactory of this type.
T	hostsFileEntriesResolver(HostsFileEntriesResolver hostsFileEntriesResolver)
T	localAddress(InetSocketAddress localAddress) Sets the local address of the DatagramChannel
T	maxPayloadSize(int maxPayloadSize) Sets the capacity of the datagram packet buffer (in bytes).
T	maxQueriesPerResolve(int maxQueriesPerResolve) Sets the maximum allowed number of DNS queries to send when resolving a host name.
T	nameServerAddresses(DnsServerAddresses nameServerAddresses) Sets the addresses of the DNS server.
T	negativeTtl(int negativeTtl) Sets the TTL of the cache for the failed DNS queries (in seconds).
T	optResourceEnabled(boolean optResourceEnabled) Enable the automatic inclusion of a optional records that tries to give the remote DNS server a hint about how much data the resolver can read per response.
T	queryTimeoutMillis(long queryTimeoutMillis) Sets the timeout of each DNS query performed by this resolver (in milliseconds).
T	recursionDesired(boolean recursionDesired) Sets if this resolver has to send a DNS query with the RD (recursion desired) flag set.
T	resolveCache(DnsCache resolveCache) Sets the cache for resolution results.
T	resolvedAddressTypes(io.netty.channel.socket.InternetProtocolFamily... resolvedAddressTypes) Sets the list of the protocol families of the address resolved.
T	resolvedAddressTypes(Iterable<io.netty.channel.socket.InternetProtocolFamily> resolvedAddressTypes) Sets the list of the protocol families of the address resolved.
T	traceEnabled(boolean traceEnabled) Sets if this resolver should generate the detailed trace information in an exception message so that it is easier to understand the cause of resolution failure.
T	ttl(int minTtl, int maxTtl) Sets the minimum and maximum TTL of the cached DNS resource records (in seconds).

Methods inherited from class java.lang.Object

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

Field Detail

eventLoop

protected final io.netty.channel.EventLoop eventLoop

channelFactory

protected io.netty.bootstrap.ChannelFactory<? extends io.netty.channel.socket.DatagramChannel> channelFactory

localAddress

protected InetSocketAddress localAddress

nameServerAddresses

protected DnsServerAddresses nameServerAddresses

resolveCache

protected DnsCache resolveCache

minTtl

protected Integer minTtl

maxTtl

protected Integer maxTtl

negativeTtl

protected Integer negativeTtl

queryTimeoutMillis

protected long queryTimeoutMillis

resolvedAddressTypes

protected io.netty.channel.socket.InternetProtocolFamily[] resolvedAddressTypes

recursionDesired

protected boolean recursionDesired

maxQueriesPerResolve

protected int maxQueriesPerResolve

traceEnabled

protected boolean traceEnabled

maxPayloadSize

protected int maxPayloadSize

optResourceEnabled

protected boolean optResourceEnabled

hostsFileEntriesResolver

protected HostsFileEntriesResolver hostsFileEntriesResolver

Constructor Detail

DnsNameResolverBuilder

public DnsNameResolverBuilder(io.netty.channel.EventLoop eventLoop)

Creates a new builder.

Parameters:

eventLoop - the EventLoop the EventLoop which will perform the communication with the DNS servers.

Method Detail

channelFactory

public T channelFactory(io.netty.bootstrap.ChannelFactory<? extends io.netty.channel.socket.DatagramChannel> channelFactory)

Sets the ChannelFactory that will create a DatagramChannel.

Parameters:

channelFactory - the ChannelFactory

Returns:

this

channelType

public T channelType(Class<? extends io.netty.channel.socket.DatagramChannel> channelType)

Sets the ChannelFactory as a ReflectiveChannelFactory of this type. Use as an alternative to channelFactory(ChannelFactory).

Parameters:

channelType -

Returns:

this

localAddress

public T localAddress(InetSocketAddress localAddress)

Sets the local address of the DatagramChannel

Parameters:

localAddress - the local address

Returns:

this

nameServerAddresses

public T nameServerAddresses(DnsServerAddresses nameServerAddresses)

Sets the addresses of the DNS server.

Parameters:

nameServerAddresses - the DNS server addresses

Returns:

this

resolveCache

public T resolveCache(DnsCache resolveCache)

Sets the cache for resolution results.

Parameters:

resolveCache - the DNS resolution results cache

Returns:

this

ttl

public T ttl(int minTtl,
             int maxTtl)

Sets the minimum and maximum TTL of the cached DNS resource records (in seconds). If the TTL of the DNS resource record returned by the DNS server is less than the minimum TTL or greater than the maximum TTL, this resolver will ignore the TTL from the DNS server and use the minimum TTL or the maximum TTL instead respectively. The default value is 0 and Integer.MAX_VALUE, which practically tells this resolver to respect the TTL from the DNS server.

Parameters:

minTtl - the minimum TTL

maxTtl - the maximum TTL

Returns:

this

negativeTtl

public T negativeTtl(int negativeTtl)

Sets the TTL of the cache for the failed DNS queries (in seconds).

Parameters:

negativeTtl - the TTL for failed cached queries

Returns:

this

queryTimeoutMillis

public T queryTimeoutMillis(long queryTimeoutMillis)

Sets the timeout of each DNS query performed by this resolver (in milliseconds).

Parameters:

queryTimeoutMillis - the query timeout

Returns:

this

resolvedAddressTypes

public T resolvedAddressTypes(io.netty.channel.socket.InternetProtocolFamily... resolvedAddressTypes)

Sets the list of the protocol families of the address resolved. Usually, both InternetProtocolFamily.IPv4 and InternetProtocolFamily.IPv6 are specified in the order of preference. To enforce the resolve to retrieve the address of a specific protocol family, specify only a single InternetProtocolFamily.

Parameters:

resolvedAddressTypes - the address types

Returns:

this

resolvedAddressTypes

public T resolvedAddressTypes(Iterable<io.netty.channel.socket.InternetProtocolFamily> resolvedAddressTypes)

Sets the list of the protocol families of the address resolved. Usually, both InternetProtocolFamily.IPv4 and InternetProtocolFamily.IPv6 are specified in the order of preference. To enforce the resolve to retrieve the address of a specific protocol family, specify only a single InternetProtocolFamily.

Parameters:

resolvedAddressTypes - the address types

Returns:

this

recursionDesired

public T recursionDesired(boolean recursionDesired)

Sets if this resolver has to send a DNS query with the RD (recursion desired) flag set.

Parameters:

recursionDesired - true if recursion is desired

Returns:

this

maxQueriesPerResolve

public T maxQueriesPerResolve(int maxQueriesPerResolve)

Sets the maximum allowed number of DNS queries to send when resolving a host name.

Parameters:

maxQueriesPerResolve - the max number of queries

Returns:

this

traceEnabled

public T traceEnabled(boolean traceEnabled)

Sets if this resolver should generate the detailed trace information in an exception message so that it is easier to understand the cause of resolution failure.

Parameters:

traceEnabled - true if trace is enabled

Returns:

this

maxPayloadSize

public T maxPayloadSize(int maxPayloadSize)

Sets the capacity of the datagram packet buffer (in bytes). The default value is 4096 bytes.

Parameters:

maxPayloadSize - the capacity of the datagram packet buffer

Returns:

this

optResourceEnabled

public T optResourceEnabled(boolean optResourceEnabled)

Enable the automatic inclusion of a optional records that tries to give the remote DNS server a hint about how much data the resolver can read per response. Some DNSServer may not support this and so fail to answer queries. If you find problems you may want to disable this.

Parameters:

optResourceEnabled - if optional records inclusion is enabled

Returns:

this

hostsFileEntriesResolver

public T hostsFileEntriesResolver(HostsFileEntriesResolver hostsFileEntriesResolver)

Parameters:

hostsFileEntriesResolver - the HostsFileEntriesResolver used to first check if the hostname is locally aliased.

Returns:

this

build

public DnsNameResolver build()

Returns a new DnsNameResolver instance.

Returns:

a DnsNameResolver

build0

protected abstract DnsNameResolver build0(DnsCache cache)