io.grpc

Class NameResolver

java.lang.Object

io.grpc.NameResolver

@ExperimentalApi(value="https://github.com/grpc/grpc-java/issues/1770")
 @ThreadSafe
public abstract class NameResolver
extends Object

A pluggable component that resolves a target URI and return addresses to the caller.

A NameResolver uses the URI's scheme to determine whether it can resolve it, and uses the components after the scheme for actual resolution.

The addresses and attributes of a target may be changed over time, thus the caller registers a NameResolver.Listener to receive continuous updates.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	NameResolver.Factory
static interface	NameResolver.Listener Receives address updates.

Constructor Summary

Constructors

Constructor and Description
NameResolver()

Method Summary

Modifier and Type	Method and Description
abstract String	getServiceAuthority() Returns the authority used to authenticate connections to servers.
void	refresh() Re-resolve the name.
abstract void	shutdown() Stops the resolution.
abstract void	start(NameResolver.Listener listener) Starts the resolution.

Methods inherited from class java.lang.Object

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

Constructor Detail

NameResolver

public NameResolver()

Method Detail

getServiceAuthority

public abstract String getServiceAuthority()

Returns the authority used to authenticate connections to servers. It must be from a trusted source, because if the authority is tampered with, RPCs may be sent to the attackers which may leak sensitive user data.

An implementation must generate it without blocking, typically in line, and must keep it unchanged. NameResolvers created from the same factory with the same argument must return the same authority.

start

public abstract void start(NameResolver.Listener listener)

Starts the resolution.

Parameters:

listener - used to receive updates on the target

shutdown

public abstract void shutdown()

Stops the resolution. Updates to the Listener will stop.

refresh

public void refresh()

Re-resolve the name.

Can only be called after start(io.grpc.NameResolver.Listener) has been called.

This is only a hint. Implementation takes it as a signal but may not start resolution immediately. It should never throw.

The default implementation is no-op.