org.hawkular.agent.monitor.protocol

Interface Driver<L>

Type Parameters:

L - the type of the protocol specific location, typically a subclass of NodeLocation

All Known Implementing Classes:

DMRDriver, JMXDriver, PlatformDriver

public interface Driver<L>

An interface to encapsulate a protocol specific access to resources.

Author:

Peter Palaga

Method Summary

Modifier and Type	Method and Description
boolean	attributeExists(AttributeLocation<L> attributeLocation) Returns true if the given attributeLocation exists on a MonitoredEndpoint or false otherwise.
Object	fetchAttribute(AttributeLocation<L> attributeLocation) Fetches the attribute value specified by the given attributeLocation from a MonitoredEndpoint and returns it.
Map<L,Object>	fetchAttributeAsMap(AttributeLocation<L> attributeLocation) Fetches the attribute value specified by the given attributeLocation from a MonitoredEndpoint and returns it as the values in the given map.
<N> Map<L,N>	fetchNodes(L query) Fetches nodes that match the given query from a MonitoredEndpoint and returns them as an immutable Map.

Method Detail

fetchNodes

<N> Map<L,N> fetchNodes(L query)
                 throws ProtocolException

Fetches nodes that match the given query from a MonitoredEndpoint and returns them as an immutable Map. In a given entry in the returned map, the key is the location of the protocol specific node object that is stored in the value of the entry.

Parameters:

query - a pattern location to query for native resource nodes

Returns:

an immutable Map from locations to native resource nodes

Throws:

ProtocolException - on any problems related to the retrieval

fetchAttribute

Object fetchAttribute(AttributeLocation<L> attributeLocation)
               throws ProtocolException

Fetches the attribute value specified by the given attributeLocation from a MonitoredEndpoint and returns it. If AttributeLocation.getLocation() is a path pattern containing wildcards, then this method MAY return a List of objects that contains the attribute values of matching attributes.

Parameters:

attributeLocation - the attribute to retrieve

Returns:

the attribute value or null if there is no such attribute or if the attribute is unset.

Throws:

ProtocolException - on any problems related to the retrieval

fetchAttributeAsMap

Map<L,Object> fetchAttributeAsMap(AttributeLocation<L> attributeLocation)
                           throws ProtocolException

Fetches the attribute value specified by the given attributeLocation from a MonitoredEndpoint and returns it as the values in the given map. Assumes the AttributeLocation.getLocation() is a multi-target path (e.g. it contains wildcards) and returns a map of all attribute values keyed on the resource location. If attributeLocation is not multi-targeted the map will just contain a single entry. Use this method (as opposed to fetchAttribute(AttributeLocation)) if you need to know which resource locations returned which attribute values. The values returned are the same in both methods, this just allows you to correlate which location returned which value.

Parameters:

attributeLocation - the attribute to retrieve

Returns:

the attribute value or null if there is no such attribute or if the attribute is unset.

Throws:

ProtocolException - on any problems related to the retrieval

attributeExists

boolean attributeExists(AttributeLocation<L> attributeLocation)
                 throws ProtocolException

Returns true if the given attributeLocation exists on a MonitoredEndpoint or false otherwise. This method should return true for attributes that exist but are unset.

Parameters:

attributeLocation - the AttributeLocation to check

Returns:

true or false

Throws:

ProtocolException - on any problems related to the retrieval