indexer-core/src/main/java/org/apache/maven/index/expr/StringSearchExpression.java

package org.apache.maven.index.expr;

/*
 * 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.
 */

/**
 * A simple string based implementation of SearchExpression that is immutable.
 * 
 * @author cstamas
 */
public class StringSearchExpression
    implements SearchExpression
{
    private final String expression;

    public StringSearchExpression( final String expression )
    {
        if ( expression == null || expression.trim().length() == 0 )
        {
            throw new IllegalArgumentException( "The expression's string cannot be empty!" );
        }

        this.expression = expression;
    }

    public String getStringValue()
    {
        return expression;
    }
}