Develop Reference

Get prefixMap from Fuseki

I have java app that works with jena tdb and it works fine. Now i migrated to Fuseki and when i want to get the Prefixes i am getting empty List.
Model model = ModelFactory.createDefaultModel();
model.setNsPrefixes(resultSet.getResourceModel().getNsPrefixMap());
This is empty:
resultSet.getResourceModel().getNsPrefixMap()
When i add prefixes like this in the code instead of setting the map it works fine:
model.setNsPrefix("Hello", "http://Hello#");
But i want to get all the prefixes and not to specify them in the code. So i found something like this:
String str = "http://localhost:3030/tdb2-database/data";
Model model = FileManager.get().loadModel(str);
Like this i am getting all the prefixes but it build the model in wrong way with adding nested objects and etc.
My question is how to get the prefixes like in local Jena with getNsPrefixMap

Prefixes are for presentation and don't affect the results.
Prefixes are not part of the SPARQL result set.
You can add them locally if you want to for local presentation. One place that is common to take them from is the query used for the result set. The query object has a prologue which has the prefixes in it.

using $addToset with java morphia aggregation

I have mongodb aggregation query and it works perfectly in shell.
How can i rewrite this query to use with morphia ?
org.mongodb.morphia.aggregation.Group.addToSet(String field) accepts only one field name but i need to add object to the set.
Query:
......aggregate([
{$group:
{"_id":"$subjectHash",
"authors":{$addToSet:"$fromAddress.address"},
---->> "messageDataSet":{$addToSet:{"sentDate":"$sentDate","messageId":"$_id"}},
"messageCount":{$sum:1}}},
{$sort:{....}},
{$limit:10},
{$skip:0}
])
Java code:
AggregationPipeline aggregationPipeline = myDatastore.createAggregation(Message.class)
.group("subjectHash",
grouping("authors", addToSet("fromAddress.address")),
--------??????------>> grouping("messageDataSet", ???????),
grouping("messageCount", new Accumulator("$sum", 1))
).sort(...)).limit(...).skip(...);

That's currently not supported but if you'll file an issue I'd be happy to include that in an upcoming release.

Thanks for your answer, I can guess that according to source code. :(
I don't want to use spring-data or java-driver directly (for this project) so I changed my document representation.
Added messageDataSet object which contains sentDate and messageId (and some other nested objects) (these values become duplicated in a document which is a bad design).
Aggregation becomes : "messageDataSet":{$addToSet:"$messageDataSet"},
and Java code is: grouping("messageDataSet", addToSet("messageDataSet")),
This works with moprhia. Thanks.

Save the result set of a query against a view to a table using the java client library

Recently, one of our clients reported not being able to create a table based on a query against a view. That said, they were able to save the result of a query against a table into another table. This issue spawned a more implementation focused question using the Java client libraries. Specifically, is there any way to save the result set of a query against a view to a table using the Java client library? I will be digging and post anything that I find. That said, any early guidance would be appreciated!
To be specific and add more context, I note that the the following process failed when the query was run against a union view.
java -jar BigQueryToCloudExporter.jar ./GAFastAccessKey.p12 '' "
Select date(date_add('2014-08-09',floor(datediff(date(sec_to_timestamp(visitstarttime)),'2014-08-03')/7)*7,"DAY")) WeekEndDate
, hits.eventinfo.eventaction GA_RentalNo
, count(distinct visitID) PDP_PPC
FROM (TABLE_DATE_RANGE([Union_View.GA],
TIMESTAMP('2014-08-30'),
TIMESTAMP('2014-09-13')))
where hits.eventinfo.eventcategory='property attributes'
and brandId=121
--hits.eventinfo.eventcategory='property inquiry'
and trafficsource.medium like '%cpc%'
--and trafficsource.campaign not like '%ppb%'
and trafficsource.campaign like '%mpm%'
group each by WeekEndDate, GA_XXXXXX
order by WeekEndDate, GA_XXXXXX limit 100" StagingQueryTable QueryTable AVRO gs://XXXXXX/QueryTable*.avro
On the other hand, the following process succeeded when the query was made against a BigQuery table (keeping everything else same).
java -jar BigQueryToCloudExporter.jar ./GAFastAccessKey.p12 '' "
Select date(date_add('2014-08-09',floor(datediff(date(sec_to_timestamp(visitstarttime)),'2014-08-03')/7)*7,"DAY")) WeekEndDate
, hits.eventinfo.eventaction GA_XXXXXX
, count(distinct visitID) PDP_PPC
FROM (TABLE_DATE_RANGE([XXXXXX.ga_sessions_],
TIMESTAMP('2014-08-30'),
TIMESTAMP('2014-09-13')))
where hits.eventinfo.eventcategory='property attributes'
and brandId=121
--hits.eventinfo.eventcategory='property inquiry'
and trafficsource.medium like '%cpc%'
--and trafficsource.campaign not like '%ppb%'
and trafficsource.campaign like '%mpm%'
group each by WeekEndDate, GA_RentalNo
order by WeekEndDate, GA_XXXXXX limit 100" StagingQueryTable QueryTable AVRO gs://XXXXXX/QueryTable*.avro

Boost one value of several on field with Spring Data Solr

I have a solr field visibility that has a set of possible values and I would like to perform a search using Spring Data Solr. I'd like to use in() and boost some but not all values if possible.
Here's an example of the search I need,
visibility:(visible^1000 archived)
or
visibility:(visible^1000 draft^500 archived)
Would this be possible in version 1.0.0.RELEASE or later versions? Currently I'm using 1.0.0.RELEASE.
Thanks, /w

I never managed to chain this query properly, but was enlightened by petrikainulainen.net on SimpleStringCriteria().
Criteria criteria = new SimpleStringCriteria("(visibility:(visible^1000) OR visibility:(draft^500) OR visibility:(archived))");

By doing as shown below you will give far higher boost to the docs that has the category as 'webpage'. Then add 'combined' criteria to your existing other criteria
Criteria webpage= new Criteria("category" ).is("webpage" ).boost((float) 1000);
Criteria document= new Criteria("category" ).is("document" ).boost((float) 2);
Criteria combined= webpage.or( document);

ElasticSearch - Using FilterBuilders

I am new to ElasticSearch and Couchbase. I am building a sample Java application to learn more about ElasticSearch and Couchbase.
Reading the ElasticSearch Java API, Filters are better used in cases where sort on score is not necessary and for caching.
I still haven't figured out how to use FilterBuilders and have following questions:
Can FilterBuilders be used alone to search?
Or Do they always have to be used with a Query? ( If true, can someone please list an example? )
Going through a documentation, if I want to perform a search based on field values and want to use FilterBuilders, how can I accomplish that? (using AndFilterBuilder or TermFilterBuilder or InFilterBuilder? I am not clear about the differences between them.)
For the 3rd question, I actually tested it with search using queries and using filters as shown below.
I got empty result (no rows) when I tried search using FilterBuilders. I am not sure what am I doing wrong.
Any examples will be helpful. I have had a tough time going through documentation which I found sparse and even searching led to various unreliable user forums.
private void processQuery() {
SearchRequestBuilder srb = getSearchRequestBuilder(BUCKET);
QueryBuilder qb = QueryBuilders.fieldQuery("doc.address.state", "TX");
srb.setQuery(qb);
SearchResponse resp = srb.execute().actionGet();
System.out.println("response :" + resp);
}
private void searchWithFilters(){
SearchRequestBuilder srb = getSearchRequestBuilder(BUCKET);
srb.setFilter(FilterBuilders.termFilter("doc.address.state", "tx"));
//AndFilterBuilder andFb = FilterBuilders.andFilter();
//andFb.add(FilterBuilders.termFilter("doc.address.state", "TX"));
//srb.setFilter(andFb);
SearchResponse resp = srb.execute().actionGet();
System.out.println("response :" + resp);
}
--UPDATE--
As suggested in the answer, changing to lowercase "tx" works. With this question resolved. I still have following questions:
In what scenario(s), are filters used with query? What purpose will this serve?
Difference between InFilter, TermFilter and MatchAllFilter. Any illustration will help.

Right, you should use filters to exclude documents from being even considered when executing the query. Filters are faster since they don't involve any scoring, and cacheable as well.
That said, it's pretty obvious that you have to use a filter with the search api, which does execute a query and accepts an optional filter. If you only have a filter you can just use the match_all query together with your filter. A filter can be a simple one, or a compund one in order to combine multiple filters together.
Regarding the Java API, the names used are the names of the filters available, no big difference. Have a look at this search example for instance. In your code I don't see where you do setFilter on your SearchRequestBuilder object. You don't seem to need the and filter either, since you are using a single filter. Furthermore, it might be that you are indexing using the default mappings, thus the term "TX" is lowercased. That's why when you search using the term filter you don't find any match. Try searching for "tx" lowercased.
You can either change your mapping if you want to keep the "TX" term as it is while indexing, probably setting the field as not_analyzed if it should only be a single token. Otherwise you can change filter, you might want to have a look at a query that is analyzed, so that your query wil be analyzed the same way the content was indexed.
Have a look at the query DSL documentation for more information regarding queries and filters:
MatchAllFilter: matches all your document, not that useful I'd say
TermFilter: Filters documents that have fields that contain a term (not analyzed)
AndFilter: compound filter used to put in and two or more filters
Don't know what you mean by InFilterBuilder, couldn't find any filter with this name.
The query usually contains what the user types in through the text search box. Filters are more way to refine the search, for example clicking on facet entries. That's why you would still have the query plus one or more filters.

To append to what #javanna said:
A lot of confusion can come from the fact that filters can be defined in several ways:
standalone (with a required query, for instance match_all if all you need is the filters) (http://www.elasticsearch.org/guide/reference/api/search/filter/)
or as part of a filtered query (http://www.elasticsearch.org/guide/reference/query-dsl/filtered-query/)
What's the difference you might ask. And indeed you can construct exactly the same logic in both ways.
The difference is that a query operates on BOTH the resultset as well as any facets you have defined. Whereas, a Filter (when defined standalone) only operates on the resultset and NOT on any facets you may have defined (explained here: http://www.elasticsearch.org/guide/reference/api/search/filter/)

To add to the other answers, InFilter is only used with FilterBuilders. The definition is, InFilter: A filter for a field based on several terms matching on any of them.
The query Java API uses FilterBuilders, which is a factory for filter builders that can dynamically create a query from Java code. We do this using a form and we build our query based on user selections from it with checkboxes, options, and dropdowns.
Here is some Example code for FilterBuilders and there is a snippet from that link that uses InFilter as shown below:
FilterBuilder filterBuilder;
User user = (User) auth.getPrincipal();
if (user.getGroups() != null && !user.getGroups().isEmpty()) {
filterBuilder = FilterBuilders.boolFilter()
.should(FilterBuilders.nestedFilter("userRoles", FilterBuilders.termFilter("userRoles.key", auth.getName())))
.should(FilterBuilders.nestedFilter("groupRoles", FilterBuilders.inFilter("groupRoles.key", user.getGroups().toArray())));
} else {
filterBuilder = FilterBuilders.nestedFilter("userRoles", FilterBuilders.termFilter("userRoles.key", auth.getName()));
}
...