QBE: Flexible JPA entity querying using example objects.

How does it work

QBE inspects the supplied example object and builds JPA Criteria based on the example objects field contents.

Dependencies:

hibernate-entitymanager

Get it:

To get started using QBE, just clone and build the project:

git clone git://github.com/kenglxn/QueryByExample.git
cd QueryByExample/
mvn clean install

and then add QBE as a dependency in your project

<dependency>
<groupId>net.glxn</groupId>
<artifactId>qbe</artifactId>
<version>1.2</version>
</dependency>

If you don't want to clone and build yourself, simply grab the jars from here: https://github.com/kenglxn/QueryByExample/tree/master/dist

Then just run maven to install them into your local repo:

mvn install:install-file -Dfile=qbe-1.2.jar -DgroupId=net.glxn -DartifactId=qbe -Dversion=1.2 -Dpackaging=jar -DgeneratePom=true

Usage:

// get a list of entities using an arbitrary pojo as example inputList<Entity> resultList = QBE.using(entityManager)
.query(Entity.class)
.by(newPojo("foo"))
.list();
// get a single result using an arbitrary pojo as example inputEntityitem =
QBE.using(entityManager)
.query(Entity.class)
.by(newPojo("foo"))
.item();
// get and work with the underlying TypedQuery object (useful e.g. for paging)TypedQuery<Entity> query =
QBE.using(entityManager)
.query(Entity.class)
.by(newPojo("foo"))
.getQuery();
List<Entity> resultList =
query
.setFirstResult(0)
.setMaxResults(10)
.getResultList();
// override the Matching logic (defaults to EXACT)QBE.using(entityManager)
.query(Entity.class)
.by(newPojo("foo"))
.use(Matching.EXACT);
QBE.using(entityManager)
.query(Entity.class)
.by(newPojo("foo"))
.use(Matching.START);
QBE.using(entityManager)
.query(Entity.class)
.by(newPojo("foo"))
.use(Matching.MIDDLE);
QBE.using(entityManager)
.query(Entity.class)]
.by(newPojo("foo"))
.use(Matching.END);
// set the Case Sensitivity for the query (defaults to SENSITIVE) // if the example has a property with string 'house', using this feature// it will search e.g for 'HOUSE', 'hOUse'...QBE.using(entityManager)
.query(Entity.class)]
.by(example)
.use(Case.INSENSITIVE);
// override the Junction for multiple fields (defaults to UNION)List<Entity> resultList =
QBE.using(entityManager)
.query(Entity.class)
.by(example)
.use(Junction.INTERSECTION)
.list();
// define the ordering of the resultList<Entity> resultList =
QBE.using(entityManager)
.query(Entity.class)
.by(newPojo("foo"))
.use(Matching.START)
.orderBy(fieldToOrderBy, Order.ASCENDING)
.list();
// define multiple fields for ordering semanticsList<Entity> resultList =
QBE.using(entityManager)
.query(Entity.class)
.by(newPojo("foo"))
.use(Matching.START)
.orderBy("firstName", Order.DESCENDING)
.orderBy("lastName", Order.ASCENDING)
.list();

API Documentation

Javadocs are located here: http://kenglxn.github.io/QueryByExample/apidocs/index.html

License:

http://www.apache.org/licenses/LICENSE-2.0.html