/*
* Copyright (C) 2009 eXo Platform SAS.
*
* This is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License as published by the Free
* Software Foundation; either version 2.1 of the License, or (at your option)
* any later version.
*
* This software 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 software; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA, or see the FSF
* site: http://www.fsf.org.
*/
package org.xcmis.search.model.source.join;
import org.apache.commons.lang.Validate;
import org.apache.commons.lang.builder.EqualsBuilder;
import org.apache.commons.lang.builder.HashCodeBuilder;
import org.xcmis.search.QueryObjectModelVisitor;
import org.xcmis.search.VisitException;
import org.xcmis.search.Visitors;
import org.xcmis.search.model.column.Column;
import org.xcmis.search.model.source.SelectorName;
/**
* A join condition that tests whether a property on a node is equal to a
* property on another node. A node-tuple satisfies the constraint only if:
* <ul>
* <li>the {@code selector1Name} node has a property named {@code property1Name}
* , and</li>
* <li>the {@code selector2Name} node has a property named {@code property2Name}
* , and</li>
* <li>the value of property {@code property1Name} is equal to the value of
* property {@code property2Name}</li>
* </ul>
*
* @author <a href="mailto:Sergey.Kabashnyuk@gmail.com">Sergey Kabashnyuk</a>
* @version $Id: EquiJoinConditionImpl.java 2 2010-02-04 17:21:49Z andrew00x $
*/
public class EquiJoinCondition extends JoinCondition
{
/**
*
*/
private static final long serialVersionUID = 5357188353322766280L;
private final SelectorName selector1Name;
private final String property1Name;
private final SelectorName selector2Name;
private final String property2Name;
private final int hcode;
/**
* Create an equi-join condition, given the columns.
*
* @param column1
* the column for the left-side of the join; never null
* @param column2
* the column for the right-side of the join; never null
*/
public EquiJoinCondition(Column column1, Column column2)
{
this(column1.getSelectorName(), column1.getPropertyName(), column2.getSelectorName(), column2.getPropertyName());
}
/**
* Create an equi-join condition, given the names of the selector and
* property for the left- and right-hand-side of the join.
*
* @param selector1Name
* the selector name appearing on the left-side of the join; never
* null
* @param property1Name
* the property name for the left-side of the join; never null
* @param selector2Name
* the selector name appearing on the right-side of the join; never
* null
* @param property2Name
* the property name for the right-side of the join; never null
*/
public EquiJoinCondition(SelectorName selector1Name, String property1Name, SelectorName selector2Name,
String property2Name)
{
Validate.notNull(selector1Name, "The selector1Name argument may not be null");
Validate.notNull(property1Name, "The property1Name argument may not be null");
Validate.notNull(selector2Name, "The selector2Name argument may not be null");
Validate.notNull(property2Name, "The property2Name argument may not be null");
this.selector1Name = selector1Name;
this.property1Name = property1Name;
this.selector2Name = selector2Name;
this.property2Name = property2Name;
this.hcode = new HashCodeBuilder()
.append(selector1Name)
.append(property1Name)
.append(selector2Name)
.append(property2Name)
.toHashCode();
}
/**
* @see org.xcmis.search.model.QueryElement#accept(org.xcmis.search.QueryObjectModelVisitor)
*/
public void accept(QueryObjectModelVisitor visitor) throws VisitException
{
visitor.visit(this);
}
/**
* {@inheritDoc}
*
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object obj)
{
if (obj == null)
{
return false;
}
if (obj == this)
{
return true;
}
if (obj.getClass() != getClass())
{
return false;
}
EquiJoinCondition rhs = (EquiJoinCondition)obj;
return new EqualsBuilder()
.append(selector1Name, rhs.selector1Name)
.append(property1Name, rhs.property1Name)
.append(selector2Name, rhs.selector2Name)
.append(property2Name, rhs.property2Name)
.isEquals();
}
/**
* Get the name of the property that appears on the left-side of the join.
*
* @return the property name for the left-side of the join; never null
*/
public final String getProperty1Name()
{
return property1Name;
}
/**
* Get the name of the property that appears on the left-side of the join.
*
* @return the property name for the left-side of the join; never null
*/
public final String getProperty2Name()
{
return property2Name;
}
/**
* Get the name of the selector that appears on the left-side of the join.
*
* @return the selector name appearing on the left-side of the join; never
* null
*/
public final SelectorName getSelector1Name()
{
return selector1Name;
}
/**
* Get the name of the selector that appears on the right-side of the join.
*
* @return the selector name appearing on the right-side of the join; never
* null
*/
public final SelectorName getSelector2Name()
{
return selector2Name;
}
/**
* {@inheritDoc}
*
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode()
{
return hcode;
}
/**
* {@inheritDoc}
*
* @see java.lang.Object#toString()
*/
@Override
public String toString()
{
return Visitors.readable(this);
}
}