Package org.apache.hadoop.ipc

Class RefreshRegistry

java.lang.Object

org.apache.hadoop.ipc.RefreshRegistry

@Unstable
public class RefreshRegistry
extends Object

Used to registry custom methods to refresh at runtime. Each identifier maps to one or more RefreshHandlers.

Field Summary

Fields

Modifier and Type	Field	Description
static final org.slf4j.Logger	LOG

Constructor Summary

Constructors

Constructor	Description
RefreshRegistry()

Method Summary

Modifier and Type	Method	Description
static RefreshRegistry	defaultRegistry()
Collection<RefreshResponse>	dispatch(String identifier, String[] args)	Lookup the responsible handler and return its result.
void	register(String identifier, RefreshHandler handler)	Registers an object as a handler for a given identity.
boolean	unregister(String identifier, RefreshHandler handler)	Remove the registered object for a given identity.
void	unregisterAll(String identifier)

Methods inherited from class java.lang.Object

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

Field Details

LOG

public static final org.slf4j.Logger LOG

Constructor Details

RefreshRegistry

public RefreshRegistry()

Method Details

defaultRegistry

public static RefreshRegistry defaultRegistry()

register

public void register(String identifier,
 RefreshHandler handler)

Registers an object as a handler for a given identity. Note: will prevent handler from being GC'd, object should unregister itself when done

Parameters:

identifier - a unique identifier for this resource, such as org.apache.hadoop.blacklist

handler - the object to register

unregister

public boolean unregister(String identifier,
 RefreshHandler handler)

Remove the registered object for a given identity.

Parameters:

identifier - the resource to unregister

handler - input handler.

Returns:

the true if removed

unregisterAll

public void unregisterAll(String identifier)

dispatch

public Collection<RefreshResponse> dispatch(String identifier,
 String[] args)

Lookup the responsible handler and return its result. This should be called by the RPC server when it gets a refresh request.

Parameters:

identifier - the resource to refresh

args - the arguments to pass on, not including the program name

Returns:

the response from the appropriate handler

Throws:

IllegalArgumentException - on invalid identifier