org.apache.marmotta.ldclient.services.provider

Class AbstractHttpProvider

java.lang.Object

org.apache.marmotta.ldclient.services.provider.AbstractHttpProvider

All Implemented Interfaces:

DataProvider

Direct Known Subclasses:

AbstractHTMLDataProvider, AbstractXMLDataProvider

public abstract class AbstractHttpProvider
extends Object
implements DataProvider

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Author: Sebastian Schaffert

Field Summary

Fields

Modifier and Type	Field and Description
static int	RETRY_AFTER

Constructor Summary

Constructors

Constructor and Description
AbstractHttpProvider()

Method Summary

Methods

Modifier and Type	Method and Description
protected abstract List<String>	buildRequestUrl(String resourceUri, Endpoint endpoint) Build the URL to use to call the webservice in order to retrieve the data for the resource passed as argument.
protected boolean	isValidContentType(String contentType, Endpoint endpoint) Check whether the content type returned by the server is acceptable to the endpoint and data provider
protected abstract List<String>	parseResponse(String resourceUri, String requestUrl, org.openrdf.model.Model model, InputStream in, String contentType) Parse the HTTP response entity returned by the web service call and return its contents in a Sesame RDF repository also passed as argument.
ClientResponse	retrieveResource(String resource, LDClientService client, Endpoint endpoint) Retrieve the data for a resource using the given http client and endpoint definition.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.marmotta.ldclient.api.provider.DataProvider

getName, listMimeTypes

Field Detail

RETRY_AFTER

public static final int RETRY_AFTER

See Also:

Constant Field Values

Constructor Detail

AbstractHttpProvider

public AbstractHttpProvider()

Method Detail

buildRequestUrl

protected abstract List<String> buildRequestUrl(String resourceUri,
                           Endpoint endpoint)
                                         throws DataRetrievalException

Build the URL to use to call the webservice in order to retrieve the data for the resource passed as argument. In many cases, this will just return the URI of the resource (e.g. Linked Data), but there might be data providers that use different means for accessing the data for a resource, e.g. SPARQL or a Cache.

Parameters:

resourceUri -

endpoint - endpoint configuration for the data provider (optional)

Returns:

Throws:

DataRetrievalException

parseResponse

protected abstract List<String> parseResponse(String resourceUri,
                         String requestUrl,
                         org.openrdf.model.Model model,
                         InputStream in,
                         String contentType)
                                       throws DataRetrievalException

Parse the HTTP response entity returned by the web service call and return its contents in a Sesame RDF repository also passed as argument. The content type returned by the web service is passed as argument to help the implementation decide how to parse the data. The implementation can return a list of additional pages to retrieve for completing the data of the resource

Parameters:

resourceUri -

model - an RDF repository for storing an RDF representation of the dataset located at the remote resource.

in - input stream as returned by the remote webservice

contentType - content type as returned in the HTTP headers of the remote webservice

Returns:

a possibly empty list of URLs of additional resources to retrieve to complete the content

Throws:

IOException - in case an error occurs while reading the input stream

DataRetrievalException

retrieveResource

public ClientResponse retrieveResource(String resource,
                              LDClientService client,
                              Endpoint endpoint)
                                throws DataRetrievalException

Retrieve the data for a resource using the given http client and endpoint definition. The service is supposed to manage the connection handling itself. See AbstractHttpProvider for a generic implementation of this method.

Specified by:

retrieveResource in interface DataProvider

Parameters:

resource - the resource to be retrieved

endpoint - the endpoint definition

Returns:

a completely specified client response, including expiry information and the set of triples

Throws:

DataRetrievalException

isValidContentType

protected boolean isValidContentType(String contentType,
                         Endpoint endpoint)

Check whether the content type returned by the server is acceptable to the endpoint and data provider