org.carrot2.source.xml

Class RemoteXmlSimpleSearchEngineBase

java.lang.Object

org.carrot2.core.ProcessingComponentBase

org.carrot2.source.SearchEngineBase

org.carrot2.source.SimpleSearchEngine

org.carrot2.source.xml.RemoteXmlSimpleSearchEngineBase

All Implemented Interfaces:

IDocumentSource, IProcessingComponent

Direct Known Subclasses:

EToolsDocumentSource, SolrDocumentSource

@Bindable
public abstract class RemoteXmlSimpleSearchEngineBase
extends SimpleSearchEngine

A base class for implementing data sources based on XML/XSLT. The XSLT stylesheet will be loaded once during component initialization and cached for all further requests.

Field Summary

Fields

Modifier and Type	Field and Description
HttpRedirectStrategy	redirectStrategy HTTP redirect response strategy (follow or throw an error).
XmlDocumentSourceHelper	xmlDocumentSourceHelper A helper class that groups common functionality for XML/XSLT based data sources.

Fields inherited from class org.carrot2.source.SearchEngineBase

compressed, documents, POSTPROCESSING, query, results, resultsTotal, SERVICE, start, statistics

Constructor Summary

Constructors

Constructor and Description
RemoteXmlSimpleSearchEngineBase()

Method Summary

Modifier and Type	Method and Description
protected void	afterFetch(SearchEngineResponse response, ProcessingResult processingResult) Invoked after the response has been partially parsed and ProcessingResult deserialized.
void	beforeProcessing() Invoked after the attributes marked with Processing and Input annotations have been bound, but before a call to IProcessingComponent.process().
protected abstract String	buildServiceUrl() Builds the URL from which XML stream will be fetched.
protected SearchEngineResponse	fetchSearchResponse() Requests and returns results from the underlying search engine.
protected String	getPassword() Returns the password to use for HTTP Basic Authentication.
protected String	getUser() Returns the user name to use for HTTP Basic Authentication.
protected Map<String,String>	getXsltParameters() Returns parameters to be passed to the XSLT transformer.
protected abstract IResource	getXsltResource() Returns the XSLT stylesheet that transforms the custom XML into Carrot2 compliant XML.
void	init(IControllerContext context) Invoked after component's attributes marked with Init and Input annotations have been bound, but before calls to any other methods of this component.
protected ProcessingResult	loadProcessingResult(String url, Templates stylesheet, Map<String,String> xsltParameters, Map<String,Object> metadata, String user, String password, HttpRedirectStrategy redirectStrategy) Loads a ProcessingResult from the provided remote URL, applying XSLT transform if specified.

Methods inherited from class org.carrot2.source.SimpleSearchEngine

process

Methods inherited from class org.carrot2.source.SearchEngineBase

afterFetch, clean, urlEncode

Methods inherited from class org.carrot2.core.ProcessingComponentBase

afterProcessing, dispose, getContext, getSharedExecutor

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.carrot2.core.IProcessingComponent

afterProcessing, dispose

Field Detail

xmlDocumentSourceHelper

public final XmlDocumentSourceHelper xmlDocumentSourceHelper

A helper class that groups common functionality for XML/XSLT based data sources.

redirectStrategy

@Input
 @Processing
 @Attribute
 @Label(value="HTTP redirect strategy")
 @Level(value=MEDIUM)
 @Group(value="Service")
 @Internal
public HttpRedirectStrategy redirectStrategy

HTTP redirect response strategy (follow or throw an error).

Constructor Detail

RemoteXmlSimpleSearchEngineBase

public RemoteXmlSimpleSearchEngineBase()

Method Detail

init

public void init(IControllerContext context)

Description copied from interface: IProcessingComponent

Invoked after component's attributes marked with Init and Input annotations have been bound, but before calls to any other methods of this component. After a call to this method completes without an exception, attributes marked with Init Output will be collected. In this method, components should perform initializations based on the initialization-time attributes. This method is called once in the life time of a processing component instance.

Specified by:

init in interface IProcessingComponent

Overrides:

init in class ProcessingComponentBase

Parameters:

context - An instance of IControllerContext of the controller to which this component instance will be bound.

beforeProcessing

public void beforeProcessing()
                      throws ProcessingException

Description copied from interface: IProcessingComponent

Invoked after the attributes marked with Processing and Input annotations have been bound, but before a call to IProcessingComponent.process(). In this method, the processing component should perform any initializations based on the runtime attributes. This method is called once per request.

Specified by:

beforeProcessing in interface IProcessingComponent

Overrides:

beforeProcessing in class ProcessingComponentBase

Throws:

ProcessingException - when processing cannot start, e.g. because some attributes were not bound. If thrown, the IProcessingComponent.process() method will not be called. Instead, IProcessingComponent.afterProcessing() will be called immediately to allow clean-up actions, and the component will be ready to accept further requests or to be disposed of. Finally, the exception will be rethrown from the controller method that caused the component to perform processing.

fetchSearchResponse

protected SearchEngineResponse fetchSearchResponse()
                                            throws Exception

Description copied from class: SimpleSearchEngine

Requests and returns results from the underlying search engine.

Specified by:

fetchSearchResponse in class SimpleSearchEngine

Throws:

Exception - in case of problems with the underlying search engine

afterFetch

protected void afterFetch(SearchEngineResponse response,
                          ProcessingResult processingResult)

Invoked after the response has been partially parsed and ProcessingResult deserialized.

getXsltResource

protected abstract IResource getXsltResource()

Returns the XSLT stylesheet that transforms the custom XML into Carrot2 compliant XML. This method will be called once during component initialization. Initialization time attributes will have been bound before the call to this method.

getXsltParameters

protected Map<String,String> getXsltParameters()

Returns parameters to be passed to the XSLT transformer. This method will be called once per processing cycle. Processing-time attributes will have been bound before this method the call to this method. The default implementation returns null.

buildServiceUrl

protected abstract String buildServiceUrl()

Builds the URL from which XML stream will be fetched. This method will be called once per request processing cycle. Processing-time attributes will have been bound before this method the call to this method.

getUser

protected String getUser()

Returns the user name to use for HTTP Basic Authentication.

getPassword

protected String getPassword()

Returns the password to use for HTTP Basic Authentication.

loadProcessingResult

protected ProcessingResult loadProcessingResult(String url,
                                                Templates stylesheet,
                                                Map<String,String> xsltParameters,
                                                Map<String,Object> metadata,
                                                String user,
                                                String password,
                                                HttpRedirectStrategy redirectStrategy)
                                         throws Exception

Loads a ProcessingResult from the provided remote URL, applying XSLT transform if specified. This method can handle gzip-compressed streams if supported by the data source.

Parameters:

metadata - if a non-null map is provided, request metadata will be put into the map.

user - if not null, the user name to use for HTTP Basic Authentication

password - if not null, the password to use for HTTP Basic Authentication

Throws:

Exception