org.hibernate.criterion.Example Maven / Gradle / Ivy
/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2010, Red Hat Inc. or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Inc.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.hibernate.criterion;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import org.hibernate.Criteria;
import org.hibernate.EntityMode;
import org.hibernate.HibernateException;
import org.hibernate.engine.spi.TypedValue;
import org.hibernate.internal.util.StringHelper;
import org.hibernate.persister.entity.EntityPersister;
import org.hibernate.type.CompositeType;
import org.hibernate.type.Type;
/**
* Support for query by example.
*
* List results = session.createCriteria(Parent.class)
* .add( Example.create(parent).ignoreCase() )
* .createCriteria("child")
* .add( Example.create( parent.getChild() ) )
* .list();
*
* "Examples" may be mixed and matched with "Expressions" in the same Criteria.
* @see org.hibernate.Criteria
* @author Gavin King
*/
public class Example implements Criterion {
private final Object entity;
private final Set excludedProperties = new HashSet();
private PropertySelector selector;
private boolean isLikeEnabled;
private Character escapeCharacter;
private boolean isIgnoreCaseEnabled;
private MatchMode matchMode;
/**
* A strategy for choosing property values for inclusion in the query
* criteria
*/
public static interface PropertySelector extends Serializable {
public boolean include(Object propertyValue, String propertyName, Type type);
}
private static final PropertySelector NOT_NULL = new NotNullPropertySelector();
private static final PropertySelector ALL = new AllPropertySelector();
private static final PropertySelector NOT_NULL_OR_ZERO = new NotNullOrZeroPropertySelector();
static final class AllPropertySelector implements PropertySelector {
public boolean include(Object object, String propertyName, Type type) {
return true;
}
private Object readResolve() {
return ALL;
}
}
static final class NotNullPropertySelector implements PropertySelector {
public boolean include(Object object, String propertyName, Type type) {
return object!=null;
}
private Object readResolve() {
return NOT_NULL;
}
}
static final class NotNullOrZeroPropertySelector implements PropertySelector {
public boolean include(Object object, String propertyName, Type type) {
return object!=null && (
!(object instanceof Number) || ( (Number) object ).longValue()!=0
);
}
private Object readResolve() {
return NOT_NULL_OR_ZERO;
}
}
/**
* Set escape character for "like" clause
*/
public Example setEscapeCharacter(Character escapeCharacter) {
this.escapeCharacter = escapeCharacter;
return this;
}
/**
* Set the property selector
*/
public Example setPropertySelector(PropertySelector selector) {
this.selector = selector;
return this;
}
/**
* Exclude zero-valued properties
*/
public Example excludeZeroes() {
setPropertySelector(NOT_NULL_OR_ZERO);
return this;
}
/**
* Don't exclude null or zero-valued properties
*/
public Example excludeNone() {
setPropertySelector(ALL);
return this;
}
/**
* Use the "like" operator for all string-valued properties
*/
public Example enableLike(MatchMode matchMode) {
isLikeEnabled = true;
this.matchMode = matchMode;
return this;
}
/**
* Use the "like" operator for all string-valued properties
*/
public Example enableLike() {
return enableLike(MatchMode.EXACT);
}
/**
* Ignore case for all string-valued properties
*/
public Example ignoreCase() {
isIgnoreCaseEnabled = true;
return this;
}
/**
* Exclude a particular named property
*/
public Example excludeProperty(String name) {
excludedProperties.add(name);
return this;
}
/**
* Create a new instance, which includes all non-null properties
* by default
* @param entity
* @return a new instance of Example
*/
public static Example create(Object entity) {
if (entity==null) throw new NullPointerException("null example");
return new Example(entity, NOT_NULL);
}
protected Example(Object entity, PropertySelector selector) {
this.entity = entity;
this.selector = selector;
}
public String toString() {
return "example (" + entity + ')';
}
private boolean isPropertyIncluded(Object value, String name, Type type) {
return !excludedProperties.contains(name) &&
!type.isAssociationType() &&
selector.include(value, name, type);
}
public String toSqlString(Criteria criteria, CriteriaQuery criteriaQuery)
throws HibernateException {
StringBuilder buf = new StringBuilder().append('(');
EntityPersister meta = criteriaQuery.getFactory().getEntityPersister( criteriaQuery.getEntityName(criteria) );
String[] propertyNames = meta.getPropertyNames();
Type[] propertyTypes = meta.getPropertyTypes();
//TODO: get all properties, not just the fetched ones!
Object[] propertyValues = meta.getPropertyValues( entity );
for (int i=0; i