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.List;


The type of a simple or compound predicate: a conjunction or
disjunction of restrictions.
A simple predicate is considered to be a conjunction with a
single conjunct.

Since:Java Persistence 2.0
/**
 * The type of a simple or compound predicate: a conjunction or
 * disjunction of restrictions.
 * A simple predicate is considered to be a conjunction with a
 * single conjunct.
 *
 * @since Java Persistence 2.0
 */
public interface Predicate extends Expression<Boolean> {

        public static enum BooleanOperator {
              AND, OR
        }
	
    
Return the boolean operator for the predicate.
If the predicate is simple, this is AND.

Returns:boolean operator for the predicate
/**
     * Return the boolean operator for the predicate.
     * If the predicate is simple, this is <code>AND</code>.
     * @return boolean operator for the predicate
     */
    BooleanOperator getOperator();
    
    
Whether the predicate has been created from another
predicate by applying the Predicate.not() method
or the CriteriaBuilder.not() method.

Returns:boolean indicating if the predicate is 
                a negated predicate
/**
     * Whether the predicate has been created from another
     * predicate by applying the <code>Predicate.not()</code> method
     * or the <code>CriteriaBuilder.not()</code> method.
     * @return boolean indicating if the predicate is 
     *                 a negated predicate
     */
    boolean isNegated();

    
Return the top-level conjuncts or disjuncts of the predicate.
Returns empty list if there are no top-level conjuncts or
disjuncts of the predicate.
Modifications to the list do not affect the query.

Returns:list of boolean expressions forming the predicate
/**
     * Return the top-level conjuncts or disjuncts of the predicate.
     * Returns empty list if there are no top-level conjuncts or
     * disjuncts of the predicate.
     * Modifications to the list do not affect the query.
     * @return list of boolean expressions forming the predicate
     */
    List<Expression<Boolean>> getExpressions();

    
Create a negation of the predicate.

Returns:negated predicate
/**
     * Create a negation of the predicate.
     * @return negated predicate 
     */
    Predicate not();

}