001package org.apache.maven.plugins.enforcer;
002
003/*
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements.  See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership.  The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License.  You may obtain a copy of the License at
011 *
012 *  http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing,
015 * software distributed under the License is distributed on an
016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017 * KIND, either express or implied.  See the License for the
018 * specific language governing permissions and limitations
019 * under the License.
020 */
021
022import org.apache.maven.enforcer.rule.api.EnforcerRuleException;
023import org.apache.maven.enforcer.rule.api.EnforcerRuleHelper;
024import org.apache.maven.plugin.logging.Log;
025import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;
026import org.codehaus.plexus.util.StringUtils;
027
028import bsh.EvalError;
029import bsh.Interpreter;
030
031/**
032 * Rule for Maven Enforcer using Beanshell to evaluate a conditional expression.
033 *
034 * @author hugonnem
035 */
036public class EvaluateBeanshell
037    extends AbstractNonCacheableEnforcerRule
038{
039
040    /** Beanshell interpreter. */
041    private static final Interpreter BSH = new Interpreter();
042
043    /** The condition to be evaluated.
044     *  
045     * @see {@link #setCondition(String)}
046     * @see {@link #getCondition()}
047     * */
048    private String condition;
049
050    public final void setCondition( String condition )
051    {
052        this.condition = condition;
053    }
054    
055    public final String getCondition()
056    {
057        return condition;
058    }
059
060    @Override
061    public void execute( EnforcerRuleHelper helper )
062        throws EnforcerRuleException
063    {
064        Log log = helper.getLog();
065
066        try
067        {
068            log.debug( "Echo condition : " + this.condition );
069            // Evaluate condition within Plexus Container
070            String script = (String) helper.evaluate( this.condition );
071            log.debug( "Echo script : " + script );
072            if ( !evaluateCondition( script, log ) )
073            {
074                String message = getMessage();
075                if ( StringUtils.isEmpty( message ) )
076                {
077                    message = "The expression \"" + condition + "\" is not true.";
078                }
079                throw new EnforcerRuleException( message );
080            }
081        }
082        catch ( ExpressionEvaluationException e )
083        {
084            throw new EnforcerRuleException( "Unable to evaluate an expression '" + condition + "'", e );
085        }
086    }
087
088    /**
089     * Evaluate expression using Beanshell.
090     *
091     * @param script the expression to be evaluated
092     * @param log the logger
093     * @return boolean the evaluation of the expression
094     * @throws EnforcerRuleException if the script could not be evaluated
095     */
096    protected boolean evaluateCondition( String script, Log log )
097        throws EnforcerRuleException
098    {
099        Boolean evaluation = Boolean.FALSE;
100        try
101        {
102            evaluation = (Boolean) BSH.eval( script );
103            log.debug( "Echo evaluating : " + evaluation );
104        }
105        catch ( EvalError ex )
106        {
107            throw new EnforcerRuleException( "Couldn't evaluate condition: " + script, ex );
108        }
109        return evaluation.booleanValue();
110    }
111}