Examples with LDPathSelect org.apache.stanbol.entityhub.ldpath.query.LDPathSelect used on opensource projects

Example 1 with LDPathSelect

use of org.apache.stanbol.entityhub.ldpath.query.LDPathSelect in project stanbol by apache.

the class SiteManagerRootResource method executeLDPathQuery.

/**
     * Execute a Query that uses LDPath to process results.
     * @param query the query
     * @param mediaType the mediaType for the response
     * @param headers the http headers of the request
     * @return the response
     */
private Response executeLDPathQuery(SiteManager manager, FieldQuery query, String ldpathProgramString, MediaType mediaType, HttpHeaders headers) {
    QueryResultList<Representation> result;
    ValueFactory vf = new RdfValueFactory(new IndexedGraph());
    SiteManagerBackend backend = new SiteManagerBackend(manager);
    EntityhubLDPath ldPath = new EntityhubLDPath(backend, vf);
    //copy the selected fields, because we might need to delete some during
    //the preparation phase
    Set<String> selectedFields = new HashSet<String>(query.getSelectedFields());
    //first prepare (only execute the query if the parameters are valid)
    Program<Object> program;
    try {
        program = prepareQueryLDPathProgram(ldpathProgramString, selectedFields, backend, ldPath);
    } catch (LDPathParseException e) {
        log.warn("Unable to parse LDPath program used as select for a Query to the '/sites' endpoint:");
        log.warn("FieldQuery: \n {}", query);
        log.warn("LDPath: \n {}", ((LDPathSelect) query).getLDPathSelect());
        log.warn("Exception:", e);
        return Response.status(Status.BAD_REQUEST).entity(("Unable to parse LDPath program (Messages: " + getLDPathParseExceptionMessage(e) + ")!\n")).header(HttpHeaders.ACCEPT, mediaType).build();
    } catch (IllegalStateException e) {
        log.warn("parsed LDPath program is not compatible with the Query " + "parsed to the '/sites' endpoint!", e);
        return Response.status(Status.BAD_REQUEST).entity(e.getMessage()).header(HttpHeaders.ACCEPT, mediaType).build();
    }
    //2. execute the query
    // we need to adapt from Entity to Representation
    //TODO: should we add the metadata to the result?
    Iterator<Representation> resultIt = new AdaptingIterator<Entity, Representation>(manager.findEntities(query).iterator(), new AdaptingIterator.Adapter<Entity, Representation>() {

        @Override
        public Representation adapt(Entity value, Class<Representation> type) {
            return value.getRepresentation();
        }
    }, Representation.class);
    //process the results
    Collection<Representation> transformedResults = transformQueryResults(resultIt, program, selectedFields, ldPath, backend, vf);
    result = new QueryResultListImpl<Representation>(query, transformedResults, Representation.class);
    ResponseBuilder rb = Response.ok(result);
    rb.header(HttpHeaders.CONTENT_TYPE, mediaType + "; charset=utf-8");
    //addCORSOrigin(servletContext, rb, headers);
    return rb.build();
}

Example 2 with LDPathSelect

use of org.apache.stanbol.entityhub.ldpath.query.LDPathSelect in project stanbol by apache.

the class ReferencedSiteRootResource method executeLDPathQuery.

/**
     * Execute a Query that uses LDPath to process results.
     * @param query the query
     * @param mediaType the mediaType for the response
     * @param headers the http headers of the request
     * @return the response
     */
private Response executeLDPathQuery(Site site, FieldQuery query, String ldpathProgramString, MediaType mediaType, HttpHeaders headers) {
    QueryResultList<Representation> result;
    ValueFactory vf = new RdfValueFactory(new IndexedGraph());
    SiteBackend backend = new SiteBackend(site, vf);
    EntityhubLDPath ldPath = new EntityhubLDPath(backend, vf);
    //copy the selected fields, because we might need to delete some during
    //the preparation phase
    Set<String> selectedFields = new HashSet<String>(query.getSelectedFields());
    //first prepare (only execute the query if the parameters are valid)
    Program<Object> program;
    try {
        program = prepareQueryLDPathProgram(ldpathProgramString, selectedFields, backend, ldPath);
    } catch (LDPathParseException e) {
        log.warn("Unable to parse LDPath program used as select for Query:");
        log.warn("FieldQuery: \n {}", query);
        log.warn("LDPath: \n {}", ((LDPathSelect) query).getLDPathSelect());
        log.warn("Exception:", e);
        return Response.status(Status.BAD_REQUEST).entity(("Unable to parse LDPath program (Messages: " + getLDPathParseExceptionMessage(e) + ")!\n")).header(HttpHeaders.ACCEPT, mediaType).build();
    } catch (IllegalStateException e) {
        log.warn("parsed LDPath program is not compatible with parsed Query!", e);
        return Response.status(Status.BAD_REQUEST).entity(e.getMessage()).header(HttpHeaders.ACCEPT, mediaType).build();
    }
    //2. execute the query
    Iterator<Representation> resultIt;
    try {
        // we need to adapt from Entity to Representation
        resultIt = new AdaptingIterator<Entity, Representation>(site.findEntities(query).iterator(), new AdaptingIterator.Adapter<Entity, Representation>() {

            @Override
            public Representation adapt(Entity value, Class<Representation> type) {
                return value.getRepresentation();
            }
        }, Representation.class);
    } catch (SiteException e) {
        String message = String.format("Unable to Query Site '%s' (message: %s)", site.getId(), e.getMessage());
        log.error(message, e);
        return Response.status(Status.INTERNAL_SERVER_ERROR).entity(message).header(HttpHeaders.ACCEPT, mediaType).build();
    }
    //process the results
    Collection<Representation> transformedResults = transformQueryResults(resultIt, program, selectedFields, ldPath, backend, vf);
    result = new QueryResultListImpl<Representation>(query, transformedResults, Representation.class);
    ResponseBuilder rb = Response.ok(result);
    rb.header(HttpHeaders.CONTENT_TYPE, mediaType + "; charset=utf-8");
    //addCORSOrigin(servletContext, rb, headers);
    return rb.build();
}

Example 3 with LDPathSelect

use of org.apache.stanbol.entityhub.ldpath.query.LDPathSelect in project stanbol by apache.

the class SiteManagerRootResource method executeQuery.

/**
     * Executes the query parsed by {@link #queryEntities(String, File, HttpHeaders)} or created based
     * {@link #findEntity(String, String, String, int, int, HttpHeaders)}
     * 
     * @param manager The {@link SiteManager}
     * @param query
     *            The query to execute
     * @param headers the request headers
     * @return the response (results of error)
     */
private Response executeQuery(SiteManager manager, FieldQuery query, MediaType mediaType, HttpHeaders headers) throws WebApplicationException {
    if (query instanceof LDPathSelect && ((LDPathSelect) query).getLDPathSelect() != null) {
        //use the LDPath variant to process this query
        return executeLDPathQuery(manager, query, ((LDPathSelect) query).getLDPathSelect(), mediaType, headers);
    } else {
        //use the default query execution
        QueryResultList<Representation> result = manager.find(query);
        ResponseBuilder rb = Response.ok(result);
        rb.header(HttpHeaders.CONTENT_TYPE, mediaType + "; charset=utf-8");
        //addCORSOrigin(servletContext, rb, headers);
        return rb.build();
    }
}

Example 4 with LDPathSelect

use of org.apache.stanbol.entityhub.ldpath.query.LDPathSelect in project stanbol by apache.

the class EntityhubRootResource method executeQuery.

/**
     * Executes the query parsed by {@link #queryEntities(String, File, HttpHeaders)}
     * or created based {@link #findEntity(String, String, String, String, HttpHeaders)
     * @param query The query to execute
     * @param headers The headers used to determine the media types
     * @return the response (results of error)
     */
private Response executeQuery(FieldQuery query, HttpHeaders headers, MediaType acceptedMediaType) throws WebApplicationException {
    //Entityhub entityhub = ContextHelper.getServiceFromContext(Entityhub.class, servletContext);
    if (query instanceof LDPathSelect && ((LDPathSelect) query).getLDPathSelect() != null) {
        //use the LDPath variant to process this query
        return executeLDPathQuery(entityhub, query, ((LDPathSelect) query).getLDPathSelect(), acceptedMediaType, headers);
    } else {
        //use the default query execution
        QueryResultList<Representation> result;
        try {
            result = entityhub.find(query);
        } catch (EntityhubException e) {
            String message = String.format("Exception while performing the " + "FieldQuery on the EntityHub (message: %s)", e.getMessage());
            log.error(message, e);
            return Response.status(Status.INTERNAL_SERVER_ERROR).entity(message).header(HttpHeaders.ACCEPT, acceptedMediaType).build();
        }
        ResponseBuilder rb = Response.ok(result);
        rb.header(HttpHeaders.CONTENT_TYPE, acceptedMediaType + "; charset=utf-8");
        //addCORSOrigin(servletContext, rb, headers);
        return rb.build();
    }
}

Example 5 with LDPathSelect

use of org.apache.stanbol.entityhub.ldpath.query.LDPathSelect in project stanbol by apache.

the class EntityhubRootResource method executeLDPathQuery.

/**
     * Execute a Query that uses LDPath to process results.
     * @param query the query
     * @param mediaType the mediaType for the response
     * @param headers the http headers of the request
     * @return the response
     */
private Response executeLDPathQuery(Entityhub entityhub, FieldQuery query, String ldpathProgramString, MediaType mediaType, HttpHeaders headers) {
    QueryResultList<Representation> result;
    ValueFactory vf = new RdfValueFactory(new IndexedGraph());
    EntityhubBackend backend = new EntityhubBackend(entityhub);
    EntityhubLDPath ldPath = new EntityhubLDPath(backend, vf);
    //copy the selected fields, because we might need to delete some during
    //the preparation phase
    Set<String> selectedFields = new HashSet<String>(query.getSelectedFields());
    //first prepare (only execute the query if the parameters are valid)
    Program<Object> program;
    try {
        program = prepareQueryLDPathProgram(ldpathProgramString, selectedFields, backend, ldPath);
    } catch (LDPathParseException e) {
        log.warn("Unable to parse LDPath program used as select for Query:");
        log.warn("FieldQuery: \n {}", query);
        log.warn("LDPath: \n {}", ((LDPathSelect) query).getLDPathSelect());
        log.warn("Exception:", e);
        return Response.status(Status.BAD_REQUEST).entity(("Unable to parse LDPath program (Messages: " + getLDPathParseExceptionMessage(e) + ")!\n")).header(HttpHeaders.ACCEPT, mediaType).build();
    } catch (IllegalStateException e) {
        log.warn("parsed LDPath program is not compatible with parsed Query!", e);
        return Response.status(Status.BAD_REQUEST).entity(e.getMessage()).header(HttpHeaders.ACCEPT, mediaType).build();
    }
    //2. execute the query
    Iterator<Representation> resultIt;
    try {
        // go directly to the yard and query there for Representations
        resultIt = entityhub.getYard().findRepresentation(query).iterator();
    } catch (EntityhubException e) {
        String message = String.format("Exception while performing the " + "FieldQuery on the EntityHub (message: %s)", e.getMessage());
        log.error(message, e);
        return Response.status(Status.INTERNAL_SERVER_ERROR).entity(message).header(HttpHeaders.ACCEPT, mediaType).build();
    }
    //process the results
    Collection<Representation> transformedResults = transformQueryResults(resultIt, program, selectedFields, ldPath, backend, vf);
    result = new QueryResultListImpl<Representation>(query, transformedResults, Representation.class);
    ResponseBuilder rb = Response.ok(result);
    rb.header(HttpHeaders.CONTENT_TYPE, mediaType + "; charset=utf-8");
    //addCORSOrigin(servletContext, rb, headers);
    return rb.build();
}