ddf.catalog.plugin

Interface PreFederatedQueryPlugin

All Known Subinterfaces:

QueryMonitorPlugin

All Known Implementing Classes:

QueryMonitorPluginImpl, SecurityLoggingPlugin, SourceMetricsImpl, TagsFilterQueryPlugin

public interface PreFederatedQueryPlugin

A PreFederatedQueryPlugin is used to execute functionality before a federated query has been executed. For example if a query needed to be altered, a PreFederatedQueryPlugin could be implemented to alter the query prior to execution.

Author:

rodgersh

Method Summary

Modifier and Type	Method and Description
QueryRequest	process(Source source, QueryRequest input) Processes a QueryRequest prior to execution of the Federated Query.

Method Detail

process

QueryRequest process(Source source,
                     QueryRequest input)
              throws PluginExecutionException,
                     StopProcessingException

Processes a QueryRequest prior to execution of the Federated Query.

Parameters:

source - the Source the query will be sent to

input - the QueryRequest to process

Returns:

the value of the processed QueryRequest to pass to the next PreFederatedQueryPlugin, or if this is the last PreFederatedQueryPlugin to be called

Throws:

PluginExecutionException - thrown when an error occurs while processing the QueryRequest

StopProcessingException - thrown to halt processing when a critical issue occurs during processing. This is intended to prevent other plugins from processing as well.