//$Id: Example.java,v 1.19 2005/02/21 02:46:40 oneovthafew Exp $package org.hibernate.criterion;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.TypedValue;import org.hibernate.persister.entity.EntityPersister;import org.hibernate.type.AbstractComponentType;import org.hibernate.type.Type;import org.hibernate.util.StringHelper;/** * Support for query by example. * <pre> * List results = session.createCriteria(Parent.class) *     .add( Example.create(parent).ignoreCase() ) *     .createCriteria("child") *         .add( Example.create( parent.getChild() ) ) *     .list(); * </pre> * "Examples" may be mixed and matched with "Expressions" in the same <tt>Criteria</tt>. * @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 boolean isIgnoreCaseEnabled;	private MatchMode matchMode;	/**	 * A strategy for choosing property values for inclusion in the query	 * criteria	 */	public static interface PropertySelector {		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;		}	}	static final class NotNullPropertySelector implements PropertySelector {		public boolean include(Object object, String propertyName, Type type) {			return object!=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			);		}	}	/**	 * 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 <tt>Example</tt>	 */	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 {		StringBuffer buf = new StringBuffer().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, getEntityMode(criteria, criteriaQuery) );		for (int i=0; i<propertyNames.length; i++) {			Object propertyValue = propertyValues[i];			String propertyName = propertyNames[i];			boolean isPropertyIncluded = i!=meta.getVersionProperty() &&				isPropertyIncluded( propertyValue, propertyName, propertyTypes[i] );			if (isPropertyIncluded) {				if ( propertyTypes[i].isComponentType() ) {					appendComponentCondition(						propertyName,						propertyValue,						(AbstractComponentType) propertyTypes[i],						criteria,						criteriaQuery,						buf					);				}				else {					appendPropertyCondition(						propertyName,						propertyValue,						criteria,						criteriaQuery,						buf					);				}			}		}		if ( buf.length()==1 ) buf.append("1=1"); //yuck!		return buf.append(')').toString();	}	private static final Object[] TYPED_VALUES = new TypedValue[0];	public TypedValue[] getTypedValues(Criteria criteria, CriteriaQuery criteriaQuery)	throws HibernateException {		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[] values = meta.getPropertyValues( entity, getEntityMode(criteria, criteriaQuery) );		List list = new ArrayList();		for (int i=0; i<propertyNames.length; i++) {			Object value = values[i];			Type type = propertyTypes[i];			String name = propertyNames[i];			boolean isPropertyIncluded = i!=meta.getVersionProperty() &&				isPropertyIncluded(value, name, type);			if (isPropertyIncluded) {				if ( propertyTypes[i].isComponentType() ) {					addComponentTypedValues(name, value, (AbstractComponentType) type, list, criteria, criteriaQuery);				}				else {					addPropertyTypedValue(value, type, list);				}			}		}		return (TypedValue[]) list.toArray(TYPED_VALUES);	}		private EntityMode getEntityMode(Criteria criteria, CriteriaQuery criteriaQuery) {		EntityPersister meta = criteriaQuery.getFactory()				.getEntityPersister( criteriaQuery.getEntityName(criteria) );		EntityMode result = meta.guessEntityMode(entity);		if (result==null) {			throw new ClassCastException( entity.getClass().getName() );		}		return result;	}	protected void addPropertyTypedValue(Object value, Type type, List list) {		if ( value!=null ) {			if ( value instanceof String ) {				String string = (String) value;				if (isIgnoreCaseEnabled) string = string.toLowerCase();				if (isLikeEnabled) string = matchMode.toMatchString(string);				value = string;			}			list.add( new TypedValue(type, value, null) );		}	}	protected void addComponentTypedValues(			String path, 			Object component, 			AbstractComponentType type, 			List list, 			Criteria criteria, 			CriteriaQuery criteriaQuery)	throws HibernateException {		if (component!=null) {			String[] propertyNames = type.getPropertyNames();			Type[] subtypes = type.getSubtypes();			Object[] values = type.getPropertyValues( component, getEntityMode(criteria, criteriaQuery) );			for (int i=0; i<propertyNames.length; i++) {				Object value = values[i];				Type subtype = subtypes[i];				String subpath = StringHelper.qualify( path, propertyNames[i] );				if ( isPropertyIncluded(value, subpath, subtype) ) {					if ( subtype.isComponentType() ) {						addComponentTypedValues(subpath, value, (AbstractComponentType) subtype, list, criteria, criteriaQuery);					}					else {						addPropertyTypedValue(value, subtype, list);					}				}			}		}	}	protected void appendPropertyCondition(		String propertyName,		Object propertyValue,		Criteria criteria,		CriteriaQuery cq,		StringBuffer buf)	throws HibernateException {		Criterion crit;		if ( propertyValue!=null ) {			boolean isString = propertyValue instanceof String;			String op = isLikeEnabled && isString ? " like " : "=";			crit = new SimpleExpression( propertyName, propertyValue, op, isIgnoreCaseEnabled && isString );		}		else {			crit = new NullExpression(propertyName);		}		String critCondition = crit.toSqlString(criteria, cq);		if ( buf.length()>1 && critCondition.trim().length()>0 ) buf.append(" and ");		buf.append(critCondition);	}	protected void appendComponentCondition(		String path,		Object component,		AbstractComponentType type,		Criteria criteria,		CriteriaQuery criteriaQuery,		StringBuffer buf)	throws HibernateException {		if (component!=null) {			String[] propertyNames = type.getPropertyNames();			Object[] values = type.getPropertyValues( component, getEntityMode(criteria, criteriaQuery) );			Type[] subtypes = type.getSubtypes();			for (int i=0; i<propertyNames.length; i++) {				String subpath = StringHelper.qualify( path, propertyNames[i] );				Object value = values[i];				if ( isPropertyIncluded( value, subpath, subtypes[i] ) ) {					Type subtype = subtypes[i];					if ( subtype.isComponentType() ) {						appendComponentCondition(							subpath,							value,							(AbstractComponentType) subtype,							criteria,							criteriaQuery,							buf						);					}					else {						appendPropertyCondition(							subpath,							value,							criteria,							criteriaQuery,							buf						);					}				}			}		}	}}