Package io.grpc.internal

Class DnsNameResolverProvider

java.lang.Object

io.grpc.NameResolver.Factory

io.grpc.NameResolverProvider

io.grpc.internal.DnsNameResolverProvider

public final class DnsNameResolverProvider
extends NameResolverProvider

A provider for DnsNameResolver.

It resolves a target URI whose scheme is "dns". The (optional) authority of the target URI is reserved for the address of alternative DNS server (not implemented yet). The path of the target URI, excluding the leading slash '/', is treated as the host name and the optional port to be resolved by DNS. Example target URIs:

• "dns:///foo.googleapis.com:8080" (using default DNS)
• "dns://8.8.8.8/foo.googleapis.com:8080" (using alternative DNS (not implemented yet))
• "dns:///foo.googleapis.com" (without port)

Constructor Summary

Constructors

Constructor	Description
DnsNameResolverProvider()

Method Summary

Modifier and Type	Method	Description
String	getDefaultScheme()	Returns the default scheme, which will be used to construct a URI when ManagedChannelBuilder.forTarget(String) is given an authority string instead of a compliant URI.
Collection<Class<? extends SocketAddress>>	getProducedSocketAddressTypes()	Returns the SocketAddress types this provider's name-resolver is capable of producing.
protected boolean	isAvailable()	Whether this provider is available for use, taking the current environment into consideration.
NameResolver	newNameResolver(URI targetUri, NameResolver.Args args)	Creates a NameResolver for the given target URI, or null if the given URI cannot be resolved by this factory.
int	priority()	A priority, from 0 to 10 that this provider should be used, taking the current environment into consideration.

Methods inherited from class io.grpc.NameResolverProvider

getScheme

Methods inherited from class java.lang.Object

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

Constructor Details

DnsNameResolverProvider

public DnsNameResolverProvider()

Method Details

newNameResolver

public NameResolver newNameResolver(URI targetUri,
 NameResolver.Args args)

Description copied from class: NameResolver.Factory

Creates a NameResolver for the given target URI, or null if the given URI cannot be resolved by this factory. The decision should be solely based on the scheme of the URI.

Specified by:

newNameResolver in class NameResolver.Factory

Parameters:

targetUri - the target URI to be resolved, whose scheme must not be null

args - other information that may be useful

getDefaultScheme

public String getDefaultScheme()

Description copied from class: NameResolver.Factory

Returns the default scheme, which will be used to construct a URI when ManagedChannelBuilder.forTarget(String) is given an authority string instead of a compliant URI.

Specified by:

getDefaultScheme in class NameResolver.Factory

isAvailable

protected boolean isAvailable()

Description copied from class: NameResolverProvider

Whether this provider is available for use, taking the current environment into consideration. If false, no other methods are safe to be called.

Specified by:

isAvailable in class NameResolverProvider

priority

public int priority()

Description copied from class: NameResolverProvider

A priority, from 0 to 10 that this provider should be used, taking the current environment into consideration. 5 should be considered the default, and then tweaked based on environment detection. A priority of 0 does not imply that the provider wouldn't work; just that it should be last in line.

Specified by:

priority in class NameResolverProvider

getProducedSocketAddressTypes

public Collection<Class<? extends SocketAddress>> getProducedSocketAddressTypes()

Description copied from class: NameResolverProvider

Returns the SocketAddress types this provider's name-resolver is capable of producing. This enables selection of the appropriate ManagedChannelProvider for a channel.

Overrides:

getProducedSocketAddressTypes in class NameResolverProvider

Returns:

the SocketAddress types this provider's name-resolver is capable of producing.