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1   /**
2    * Copyright 2005-2014 The Kuali Foundation
3    *
4    * Licensed under the Educational Community License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    * http://www.opensource.org/licenses/ecl2.php
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package org.kuali.rice.krms.framework.engine.expression;
17  
18  import org.kuali.rice.krms.api.engine.ExecutionEnvironment;
19  
20  /**
21   * Binary Operator implementation of Expression<Boolean>
22   *
23   * @author Kuali Rice Team (rice.collab@kuali.org)
24   *
25   */
26  public final class BinaryOperatorExpression implements Expression<Boolean> {
27  
28  	private final ComparisonOperator operator;
29  	private final Expression<? extends Object> lhs;
30  	private final Expression<? extends Object> rhs;
31  
32      /**
33       * Create a BinaryOperatorExpression with the given values
34       * @param operator {@link ComparisonOperator}
35       * @param lhs left hand side Expression
36       * @param rhs right hand side Expression
37       */
38  	public BinaryOperatorExpression(ComparisonOperator operator, Expression<? extends Object> lhs, Expression<? extends Object> rhs) {
39  		this.operator = operator;
40  		this.lhs = lhs;
41  		this.rhs = rhs;
42  	}
43  
44      @Override
45  	public Boolean invoke(ExecutionEnvironment environment) {
46  		Object lhsValue = lhs.invoke(environment);
47  		Object rhsValue = rhs.invoke(environment);
48  		return operator.compare(lhsValue, rhsValue);
49  	}
50  	
51  }