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