org.apache.geode.cache

Interface LoaderHelper<K,V>

public interface LoaderHelper<K,V>

Provides a set of APIs to help the implementation of the CacheLoader load method. An instance of LoaderHelper is only valid within the load method.

Since:

GemFire 2.0

See Also:

load

Method Summary

Modifier and Type	Method and Description
Object	getArgument() Return the argument object for the load method that was passed in from application code.
K	getKey() Returns the key for the value being loaded.
Region<K,V>	getRegion() Returns the region to which the entry belongs.
V	netSearch(boolean doNetLoad) Searches other caches for the value to be loaded.

Method Detail

netSearch

V netSearch(boolean doNetLoad)
     throws CacheLoaderException,
            TimeoutException

Searches other caches for the value to be loaded. If the cache is part of a distributed caching system, netSearch will try to locate the requested value in any other cache within the system. If the search is successful, a reference to a local copy of the value is returned. If there is no value for this entry present in the system, and doNetLoad is true, GemFire looks for and invokes CacheLoaders in other nodes in the system. The net load will invoke one loader at a time until a loader either returns a non-null value or throws an exception. If the object is not found, null is returned.

Parameters:

doNetLoad - if true, and there is no valid value found for this entry in the system, then look for and invoke loaders on other nodes

Returns:

the requested value or null if not found

Throws:

TimeoutException - if the netSearch times out before getting a response from another cache

CacheLoaderException - If netSearch is attempted on a local region.

getKey

K getKey()

Returns the key for the value being loaded.

Returns:

the name Object for the object being loaded

See Also:

load

getRegion

Region<K,V> getRegion()

Returns the region to which the entry belongs.

Returns:

the name of the region for the object being loaded

See Also:

load

getArgument

Object getArgument()

Return the argument object for the load method that was passed in from application code. This object is passed in as aLoaderArgument in get.

Returns:

the argument or null if one was not supplied