001/*
002 *  Copyright 2010 Anyware Services
003 *
004 *  Licensed under the Apache License, Version 2.0 (the "License");
005 *  you may not use this file except in compliance with the License.
006 *  You may obtain a copy of the License at
007 *
008 *      http://www.apache.org/licenses/LICENSE-2.0
009 *
010 *  Unless required by applicable law or agreed to in writing, software
011 *  distributed under the License is distributed on an "AS IS" BASIS,
012 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 *  See the License for the specific language governing permissions and
014 *  limitations under the License.
015 */
016package org.ametys.plugins.repository.query.expression;
017
018import org.apache.commons.lang.StringUtils;
019
020/**
021 * Constructs an {@link Expression} corresponding to the logical "and"
022 * between two others {@link Expression}.
023 */
024public class AndExpression implements Expression
025{
026    private Expression[] _exprs;
027
028    /**
029     * Creates the "and" Expression.
030     * @param exprs the operands
031     */
032    public AndExpression(Expression ... exprs)
033    {
034        _exprs = exprs;
035    }
036
037    public String build()
038    {
039        if (_exprs.length == 1 && _exprs[0] != null)
040        {
041            return _exprs[0].build();
042        }
043        
044        boolean isFirst = true;
045        StringBuilder sb = new StringBuilder("(");
046        
047        for (Expression expr : _exprs)
048        {
049            if (expr != null)
050            {
051                String exprAsString = expr.build();
052                if (StringUtils.isNotBlank(exprAsString))
053                {
054                    if (isFirst)
055                    {
056                        isFirst = false;
057                    }
058                    else
059                    {
060                        sb.append(" and ");
061                    }
062                    sb.append(exprAsString);
063                }
064                
065            }
066        }
067
068        if (isFirst)
069        {
070            return "";
071        }
072        else
073        {
074            return sb.append(")").toString();
075        }
076    }
077}