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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.maven.plugin;
20  
21  import java.io.File;
22  import java.nio.file.Path;
23  import java.nio.file.Paths;
24  import java.util.HashMap;
25  import java.util.Map;
26  
27  import org.apache.maven.api.MojoExecution;
28  import org.apache.maven.api.Project;
29  import org.apache.maven.api.Session;
30  import org.apache.maven.internal.impl.model.reflection.ReflectionValueExtractor;
31  import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;
32  import org.codehaus.plexus.component.configurator.expression.TypeAwareExpressionEvaluator;
33  
34  /**
35   * Evaluator for plugin parameters expressions. Content surrounded by <code>${</code> and <code>}</code> is evaluated.
36   * Recognized values are:
37   * <table border="1">
38   * <caption>Expression matrix</caption>
39   * <tr><th>expression</th>                     <th></th>               <th>evaluation result</th></tr>
40   * <tr><td><code>session.*</code></td>         <td></td>               <td></td></tr>
41   * <tr><td><code>project.*</code></td>         <td></td>               <td></td></tr>
42   * <tr><td><code>settings.*</code></td>        <td></td>               <td></td></tr>
43   * <tr><td><code>mojo.*</code></td>            <td></td>               <td>the actual {@link MojoExecution}</td></tr>
44   * <tr><td><code>*</code></td>                 <td></td>               <td>user properties</td></tr>
45   * <tr><td><code>*</code></td>                 <td></td>               <td>system properties</td></tr>
46   * <tr><td><code>*</code></td>                 <td></td>               <td>project properties</td></tr>
47   * </table>
48   *
49   * @see Session
50   * @see Project
51   * @see org.apache.maven.api.settings.Settings
52   * @see MojoExecution
53   */
54  public class PluginParameterExpressionEvaluatorV4 implements TypeAwareExpressionEvaluator {
55      private final Session session;
56  
57      private final MojoExecution mojoExecution;
58  
59      private final Project project;
60  
61      private final Path basedir;
62  
63      private final Map<String, String> properties;
64  
65      public PluginParameterExpressionEvaluatorV4(Session session, Project project) {
66          this(session, project, null);
67      }
68  
69      public PluginParameterExpressionEvaluatorV4(Session session, Project project, MojoExecution mojoExecution) {
70          this.session = session;
71          this.mojoExecution = mojoExecution;
72          this.properties = session.getEffectiveProperties(project);
73          this.project = project;
74  
75          Path basedir = null;
76  
77          if (project != null) {
78              Path projectFile = project.getBasedir();
79              basedir = projectFile.toAbsolutePath();
80          }
81  
82          if (basedir == null) {
83              basedir = session.getTopDirectory();
84          }
85  
86          if (basedir == null) {
87              basedir = Paths.get(System.getProperty("user.dir"));
88          }
89  
90          this.basedir = basedir;
91      }
92  
93      @Override
94      public Object evaluate(String expr) throws ExpressionEvaluationException {
95          return evaluate(expr, null);
96      }
97  
98      @Override
99      @SuppressWarnings("checkstyle:methodlength")
100     public Object evaluate(String expr, Class<?> type) throws ExpressionEvaluationException {
101         Object value = null;
102 
103         if (expr == null) {
104             return null;
105         }
106 
107         String expression = stripTokens(expr);
108         if (expression.equals(expr)) {
109             int index = expr.indexOf("${");
110             if (index >= 0) {
111                 int lastIndex = expr.indexOf('}', index);
112                 if (lastIndex >= 0) {
113                     String retVal = expr.substring(0, index);
114 
115                     if ((index > 0) && (expr.charAt(index - 1) == '$')) {
116                         retVal += expr.substring(index + 1, lastIndex + 1);
117                     } else {
118                         Object subResult = evaluate(expr.substring(index, lastIndex + 1));
119 
120                         if (subResult != null) {
121                             retVal += subResult;
122                         } else {
123                             retVal += "$" + expr.substring(index + 1, lastIndex + 1);
124                         }
125                     }
126 
127                     retVal += evaluate(expr.substring(lastIndex + 1));
128                     return retVal;
129                 }
130             }
131 
132             // Was not an expression
133             return expression.replace("$$", "$");
134         }
135 
136         Map<String, Object> objects = new HashMap<>();
137         objects.put("session.", session);
138         objects.put("project.", project);
139         objects.put("mojo.", mojoExecution);
140         objects.put("settings.", session.getSettings());
141         for (Map.Entry<String, Object> ctx : objects.entrySet()) {
142             if (expression.startsWith(ctx.getKey())) {
143                 try {
144                     int pathSeparator = expression.indexOf('/');
145                     if (pathSeparator > 0) {
146                         String pathExpression = expression.substring(0, pathSeparator);
147                         value = ReflectionValueExtractor.evaluate(pathExpression, ctx.getValue());
148                         if (pathSeparator < expression.length() - 1) {
149                             if (value instanceof Path) {
150                                 value = ((Path) value).resolve(expression.substring(pathSeparator + 1));
151                             } else {
152                                 value = value + expression.substring(pathSeparator);
153                             }
154                         }
155                     } else {
156                         value = ReflectionValueExtractor.evaluate(expression, ctx.getValue());
157                     }
158                     break;
159                 } catch (Exception e) {
160                     // TODO don't catch exception
161                     throw new ExpressionEvaluationException(
162                             "Error evaluating plugin parameter expression: " + expression, e);
163                 }
164             }
165         }
166 
167         /*
168          * MNG-4312: We neither have reserved all of the above magic expressions nor is their set fixed/well-known (it
169          * gets occasionally extended by newer Maven versions). This imposes the risk for existing plugins to
170          * unintentionally use such a magic expression for an ordinary property. So here we check whether we
171          * ended up with a magic value that is not compatible with the type of the configured mojo parameter (a string
172          * could still be converted by the configurator so we leave those alone). If so, back off to evaluating the
173          * expression from properties only.
174          */
175         if (value != null && type != null && !(value instanceof String) && !isTypeCompatible(type, value)) {
176             value = null;
177         }
178 
179         if (value == null) {
180             // The CLI should win for defining properties
181 
182             if (properties != null) {
183                 // We will attempt to get nab a property as a way to specify a parameter
184                 // to a plugin. My particular case here is allowing the surefire plugin
185                 // to run a single test so I want to specify that class on the cli as
186                 // a parameter.
187 
188                 value = properties.get(expression);
189             }
190         }
191 
192         if (value instanceof String) {
193             // TODO without #, this could just be an evaluate call...
194 
195             String val = (String) value;
196 
197             int exprStartDelimiter = val.indexOf("${");
198 
199             if (exprStartDelimiter >= 0) {
200                 if (exprStartDelimiter > 0) {
201                     value = val.substring(0, exprStartDelimiter) + evaluate(val.substring(exprStartDelimiter));
202                 } else {
203                     value = evaluate(val.substring(exprStartDelimiter));
204                 }
205             }
206         }
207 
208         return value;
209     }
210 
211     private static boolean isTypeCompatible(Class<?> type, Object value) {
212         if (type.isInstance(value)) {
213             return true;
214         }
215         // likely Boolean -> boolean, Short -> int etc. conversions, it's not the problem case we try to avoid
216         return ((type.isPrimitive() || type.getName().startsWith("java.lang."))
217                 && value.getClass().getName().startsWith("java.lang."));
218     }
219 
220     private String stripTokens(String expr) {
221         if (expr.startsWith("${") && (expr.indexOf('}') == expr.length() - 1)) {
222             expr = expr.substring(2, expr.length() - 1);
223         }
224         return expr;
225     }
226 
227     @Override
228     public File alignToBaseDirectory(File file) {
229         // TODO Copied from the DefaultInterpolator. We likely want to resurrect the PathTranslator or at least a
230         // similar component for re-usage
231         if (file != null) {
232             if (file.isAbsolute()) {
233                 // path was already absolute, just normalize file separator and we're done
234             } else if (file.getPath().startsWith(File.separator)) {
235                 // drive-relative Windows path, don't align with project directory but with drive root
236                 file = file.getAbsoluteFile();
237             } else {
238                 // an ordinary relative path, align with project directory
239                 file = basedir.resolve(file.getPath())
240                         .normalize()
241                         .toAbsolutePath()
242                         .toFile();
243             }
244         }
245         return file;
246     }
247 }