openjpa-persistence/src/main/java/org/apache/openjpa/persistence/query/VarArgsExpression.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.openjpa.persistence.query;

/**
 * A expression that holds an array of Expressions. Used as operand for
 * CONCAT(e1,e2,e3,...), for example. Different than {@link ArrayExpression}
 * which represents a single expression with array of values.
 *
 * @author Pinaki Poddar
 *
 */
public class VarArgsExpression extends ExpressionImpl {
	
    private static final long serialVersionUID = 1L;
    private final Expression[] _values;

	public VarArgsExpression(Expression[] values) {
		_values = values;
	}

	@Override
	public String asExpression(AliasContext ctx) {
		StringBuilder tmp = new StringBuilder();
		for (int i = 0; i < _values.length; i++) {
			Visitable v = (Visitable)_values[i];
			tmp.append(v.asExpression(ctx))
			   .append(i == _values.length-1 ? "" : ", ");
		}
		return tmp.toString();
	}

	@Override
	public String asProjection(AliasContext ctx) {
		return asExpression(ctx);
	}

}