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13.2. Querying Example
The following provides an example of how to set up and run a query in Red Hat JBoss Data Grid.
In this example, the
Person object has been annotated using the following:
Example 13.4. Annotating the Person Object
@Indexed
public class Person implements Serializable {
@Field(store = Store.YES)
private String name;
@Field
private String description;
@Field(store = Store.YES)
private int age;
}
Assuming several of these
Person objects have been stored in JBoss DataGrid, they can be searched using querying. The following code creates a SearchManager and QueryBuilder instance:
Example 13.5. Creating the SearchManager and QueryBuilder
SearchManager manager = Search.getSearchManager(cache);
QueryBuilder builder = manager.buildQueryBuilderForClass(Person.class) .get();
Query luceneQuery = builder.keyword()
.onField("name")
.matching("FirstName")
.createQuery();
The
SearchManager and QueryBuilder are used to construct a Lucene query. The Lucene query is then passed to the SearchManager to obtain a CacheQuery instance:
Example 13.6. Running the Query
CacheQuery query = manager.getQuery(luceneQuery);
List<Object> results = query.list();
for (Object result : results) {
System.out.println("Found " + result);
}
This
CacheQuery instance contains the results of the query, and can be used to produce a list or it can be used for repeat queries.
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