https://github.com/javaee/jpa-spec: Java(TM) Persistence API 
Copyright (c) 2008 - 2013 Oracle Corporation. All rights reserved.
This program and the accompanying materials are made available under the
terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
which accompanies this distribution.
The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
and the Eclipse Distribution License is available at
http://www.eclipse.org/org/documents/edl-v10.php.
Contributors:
    Linda DeMichiel - Java Persistence 2.1
    Linda DeMichiel - Java Persistence 2.0

/*******************************************************************************
 * Copyright (c) 2008 - 2013 Oracle Corporation. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Linda DeMichiel - Java Persistence 2.1
 *     Linda DeMichiel - Java Persistence 2.0
 *
 ******************************************************************************/ 
package javax.persistence.criteria;

import java.util.Map;
import javax.persistence.metamodel.MapAttribute;


The MapJoin interface is the type of the result of
joining to a collection over an association or element 
collection that has been specified as a java.util.Map.

Type parameters:
  • <Z> – the source type of the join
  • <K> – the type of the target Map key
  • <V> – the type of the target Map value
Since:Java Persistence 2.0
/**
 * The <code>MapJoin</code> interface is the type of the result of
 * joining to a collection over an association or element 
 * collection that has been specified as a <code>java.util.Map</code>.
 *
 * @param <Z> the source type of the join
 * @param <K> the type of the target Map key
 * @param <V> the type of the target Map value
 *
 * @since Java Persistence 2.0
 */
public interface MapJoin<Z, K, V> 
		extends PluralJoin<Z, Map<K, V>, V> {

    
 Modify the join to restrict the result according to the
 specified ON condition and return the join object.  
 Replaces the previous ON condition, if any.
 @param restriction  a simple or compound boolean expression
 @return the modified join object
 @since Java Persistence 2.1

/**
     *  Modify the join to restrict the result according to the
     *  specified ON condition and return the join object.  
     *  Replaces the previous ON condition, if any.
     *  @param restriction  a simple or compound boolean expression
     *  @return the modified join object
     *  @since Java Persistence 2.1
     */
    MapJoin<Z, K, V> on(Expression<Boolean> restriction);

    
 Modify the join to restrict the result according to the
 specified ON condition and return the join object.  
 Replaces the previous ON condition, if any.
 @param restrictions  zero or more restriction predicates
 @return the modified join object
 @since Java Persistence 2.1

/**
     *  Modify the join to restrict the result according to the
     *  specified ON condition and return the join object.  
     *  Replaces the previous ON condition, if any.
     *  @param restrictions  zero or more restriction predicates
     *  @return the modified join object
     *  @since Java Persistence 2.1
     */
    MapJoin<Z, K, V> on(Predicate... restrictions);

    
Return the metamodel representation for the map attribute.

Returns:metamodel type representing the Map that is
        the target of the join
/**
     * Return the metamodel representation for the map attribute.
     * @return metamodel type representing the <code>Map</code> that is
     *         the target of the join
     */
    MapAttribute<? super Z, K, V> getModel();
    
    
Create a path expression that corresponds to the map key.

Returns:path corresponding to map key
/**
     * Create a path expression that corresponds to the map key.
     * @return path corresponding to map key
     */
    Path<K> key();
    
    
Create a path expression that corresponds to the map value.
This method is for stylistic use only: it just returns this.

Returns:path corresponding to the map value
/**
     * Create a path expression that corresponds to the map value.
     * This method is for stylistic use only: it just returns this.
     * @return path corresponding to the map value
     */
    Path<V> value(); 
    
    
Create an expression that corresponds to the map entry.

Returns:expression corresponding to the map entry
/**
     * Create an expression that corresponds to the map entry.
     * @return expression corresponding to the map entry
     */
    Expression<Map.Entry<K, V>> entry();
}