In order to run these examples, make sure that the default corpus is populated as described in the Installation guide.
When you search documents by using filters, you need to apply at least one restriction.
Document-level features are defined by the user. You should add them to the documents and fill in their values. In short, a restriction filter is converted into a query "WHERE" clause. The document IDs returned by the getDocIds() method correspond to this clause. You can also sort the results by giving the method a second parameter that corresponds to an "ORDER BY" clause (this is not shown in the example).
Keyword search uses a Lucene implemented search. By default, Lucene supports only the "body" feature that corresponds to the document content. But you can also define custom features for the documents at Lucene store-level. You can index and use them for searching as shown below. For each document, the getDocsIds() method checks if the requested features contain certain words and word sequences.
The only difference between this example and the example above is that the getDocuments() method is given an entity collection. This collection is the result of an entity search by semantic query (see Searching for Entities ).