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16.3. Running Infinispan Query DSL-based Queries
Once Infinispan Query DSL-based queries have been enabled, obtain a
QueryFactory from the Search in order to run a DSL-based query.
Obtain a QueryFactory for a Cache
In Library mode, obtain a QueryFactory as follows:
QueryFactory qf = org.infinispan.query.Search.getQueryFactory(cache)
Example 16.1. Constructing a DSL-based Query
import org.infinispan.query.Search;
import org.infinispan.query.dsl.QueryFactory;
import org.infinispan.query.dsl.Query;
QueryFactory qf = Search.getQueryFactory(cache);
Query q = qf.from(User.class)
.having("name").eq("John")
.toBuilder().build();
List list = q.list();
assertEquals(1, list.size());
assertEquals("John", list.get(0).getName());
assertEquals("Doe", list.get(0).getSurname());
When using Remote Querying in Remote Client-Server mode, the
Search object resides in package org.infinispan.client.hotrod. See the example in Section 17.2, “Performing Remote Queries via the Hot Rod Java Client” for details.
It is also possible to combine multiple conditions with boolean operators, including sub-conditions. For example:
Example 16.2. Combining Multiple Conditions
Query q = qf.from(User.class)
.having("name").eq("John")
.and().having("surname").eq("Doe")
.and().not(qf.having("address.street").like("%Tanzania%")
.or().having("address.postCode").in("TZ13", "TZ22"))
.toBuilder().build();
This query API simplifies the way queries are written by not exposing the user to the low level details of constructing Lucene query objects. It also has the benefit of being available to remote Hot Rod clients.
The following example shows how to write a query for the
Book entity.
Example 16.3. Querying the Book Entity
import org.infinispan.query.Search;
import org.infinispan.query.dsl.*;
// get the DSL query factory, to be used for constructing the Query object:
QueryFactory qf = Search.getQueryFactory(cache);
// create a query for all the books that have a title which contains the word "engine":
Query query = qf.from(Book.class)
.having("title").like("%engine%")
.toBuilder().build();
// get the results
List<Book> list = query.list();