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1   package org.apache.maven.plugins.enforcer;
2   
3   /*
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *  http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  
22  import org.apache.maven.enforcer.rule.api.EnforcerRuleException;
23  import org.apache.maven.enforcer.rule.api.EnforcerRuleHelper;
24  import org.apache.maven.plugin.logging.Log;
25  import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;
26  import org.codehaus.plexus.util.StringUtils;
27  
28  import bsh.EvalError;
29  import bsh.Interpreter;
30  
31  /**
32   * Rule for Maven Enforcer using Beanshell to evaluate a conditional expression.
33   *
34   * @author hugonnem
35   */
36  public class EvaluateBeanshell
37      extends AbstractNonCacheableEnforcerRule
38  {
39  
40      /** Beanshell interpreter. */
41      private static final Interpreter bsh = new Interpreter();
42  
43      /** The condition to be evaluated. */
44      public String condition;
45  
46      /*
47       * (non-Javadoc)
48       *
49       * @see org.apache.maven.enforcer.rule.api.EnforcerRule#execute(org.apache.maven.enforcer.rule.api.EnforcerRuleHelper)
50       */
51      public void execute( EnforcerRuleHelper helper )
52          throws EnforcerRuleException
53      {
54          Log log = helper.getLog();
55  
56          try
57          {
58              log.debug( "Echo condition : " + this.condition );
59              // Evaluate condition within Plexus Container
60              String script = (String) helper.evaluate( this.condition );
61              log.debug( "Echo script : " + script );
62              if ( !evaluateCondition( script, log ) )
63              {
64                  if ( StringUtils.isEmpty( message ) )
65                  {
66                      message = "The expression \"" + condition + "\" is not true.";
67                  }
68                  throw new EnforcerRuleException( this.message );
69              }
70          }
71          catch ( ExpressionEvaluationException e )
72          {
73              throw new EnforcerRuleException( "Unable to evaluate an expression '" + condition + "'", e );
74          }
75      }
76  
77      /**
78       * Evaluate expression using Beanshell.
79       *
80       * @param script the expression to be evaluated
81       * @param log the logger
82       * @return boolean the evaluation of the expression
83       * @throws EnforcerRuleException if the script could not be evaluated
84       */
85      protected boolean evaluateCondition( String script, Log log )
86          throws EnforcerRuleException
87      {
88          Boolean evaluation = Boolean.FALSE;
89          try
90          {
91              evaluation = (Boolean) bsh.eval( script );
92              log.debug( "Echo evaluating : " + evaluation );
93          }
94          catch ( EvalError ex )
95          {
96              throw new EnforcerRuleException( "Couldn't evaluate condition: " + script, ex );
97          }
98          return evaluation.booleanValue();
99      }
100 }