0.8.1-rc1/catalog/src/main/java/org/apache/oodt/cas/catalog/query/QueryExpression.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.oodt.cas.catalog.query;

//JDK imports
import java.util.HashSet;
import java.util.Set;

/**
 * @author bfoster
 * @version $Revision$
 *
 * <p>
 * A Expression for querying against a CatalogServices Metadata
 * <p>
 */
public abstract class QueryExpression implements Cloneable {
    
    protected Set<String> bucketNames;
    
    public QueryExpression() {}
    
    public QueryExpression(Set<String> bucketNames) { 
    	this.bucketNames = new HashSet<String>(bucketNames);
    }
    
	public Set<String> getBucketNames() {
		return (this.bucketNames != null) ? new HashSet<String>(this.bucketNames) : null;
	}

	public void setBucketNames(Set<String> bucketNames) {
		this.bucketNames = bucketNames;
	}

	public abstract String toString();

    public abstract QueryExpression clone();
    
}