o Fixing a NullPointerException in the value extractor if the specified getter

didn't exists. The value extractor will now return null if the getter doesn't
  exists.
o Properly implemented the method caching in the value exctrator.
o Changed the RegexBasedModelInterpolator so it would properly handle null
  values. It used to convert null to "null" and then insert that, now it will
  leave the expression as is.


git-svn-id: https://svn.apache.org/repos/asf/maven/components/trunk@163696 13f79535-47bb-0310-9956-ffa450edef68

maven-core/src/main/java/org/apache/maven/project/interpolation/RegexBasedModelInterpolator.java

@@ -1,20 +1,19 @@
 package org.apache.maven.project.interpolation;
 
-/* ====================================================================
+/*
- *   Copyright 2001-2004 The Apache Software Foundation.
+ * Copyright 2001-2005 The Apache Software Foundation.
  *
- *   Licensed under the Apache License, Version 2.0 (the "License");
+ * Licensed under the Apache License, Version 2.0 (the "License");
- *   you may not use this file except in compliance with the License.
+ * you may not use this file except in compliance with the License.
- *   You may obtain a copy of the License at
+ * You may obtain a copy of the License at
  *
- *       http://www.apache.org/licenses/LICENSE-2.0
+ *      http://www.apache.org/licenses/LICENSE-2.0
  *
- *   Unless required by applicable law or agreed to in writing, software
+ * Unless required by applicable law or agreed to in writing, software
- *   distributed under the License is distributed on an "AS IS" BASIS,
+ * distributed under the License is distributed on an "AS IS" BASIS,
- *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *   See the License for the specific language governing permissions and
+ * See the License for the specific language governing permissions and
- *   limitations under the License.
+ * limitations under the License.
- * ====================================================================
  */
 
 import org.apache.maven.model.Model;
@@ -32,12 +31,12 @@ import java.util.regex.Pattern;
 
 /**
  * @author jdcasey Created on Feb 3, 2005
+ * @version $Id$
  */
 public class RegexBasedModelInterpolator
     extends AbstractLogEnabled
     implements ModelInterpolator
 {
-
     private static final Pattern EXPRESSION_PATTERN = Pattern.compile( "\\$\\{(pom|project\\.)?([^}]+)\\}" );
 
     /**
@@ -89,10 +88,11 @@ public class RegexBasedModelInterpolator
             String wholeExpr = matcher.group( 0 );
             String realExpr = matcher.group( 2 );
 
-            String value = null;
+            Object value = null;
+
             try
             {
-                value = String.valueOf( ReflectionValueExtractor.evaluate( realExpr, model ) );
+                value = ReflectionValueExtractor.evaluate( realExpr, model );
             }
             catch ( Exception e )
             {
@@ -105,15 +105,14 @@ public class RegexBasedModelInterpolator
 
             if ( value != null )
             {
-                result = StringUtils.replace( result, wholeExpr, value );
+                result = StringUtils.replace( result, wholeExpr, String.valueOf( value ) );
                 // could use:
-                // result = matcher.replaceFirst( value );
+                // result = matcher.replaceFirst( stringValue );
-                // but this could result in multiple lookups of value, and replaceAll is not correct behaviour 
+                // but this could result in multiple lookups of stringValue, and replaceAll is not correct behaviour
                 matcher.reset( result );
             }
         }
 
         return result;
     }
-
 }

maven-core/src/main/java/org/apache/maven/util/introspection/ReflectionValueExtractor.java

@@ -1,43 +1,41 @@
 package org.apache.maven.util.introspection;
 
-/* ====================================================================
+/*
- *   Copyright 2001-2004 The Apache Software Foundation.
+ * Copyright 2001-2005 The Apache Software Foundation.
  *
- *   Licensed under the Apache License, Version 2.0 (the "License");
+ * Licensed under the Apache License, Version 2.0 (the "License");
- *   you may not use this file except in compliance with the License.
+ * you may not use this file except in compliance with the License.
- *   You may obtain a copy of the License at
+ * You may obtain a copy of the License at
  *
- *       http://www.apache.org/licenses/LICENSE-2.0
+ *      http://www.apache.org/licenses/LICENSE-2.0
  *
- *   Unless required by applicable law or agreed to in writing, software
+ * Unless required by applicable law or agreed to in writing, software
- *   distributed under the License is distributed on an "AS IS" BASIS,
+ * distributed under the License is distributed on an "AS IS" BASIS,
- *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *   See the License for the specific language governing permissions and
+ * See the License for the specific language governing permissions and
- *   limitations under the License.
+ * limitations under the License.
- * ====================================================================
  */
 
-import org.codehaus.plexus.util.StringUtils;
-
 import java.lang.reflect.Method;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.StringTokenizer;
 
+import org.codehaus.plexus.util.StringUtils;
+
 /**
  * Using simple dotted expressions extract the values from a MavenProject
  * instance, For example we might want to extract a value like:
  * project.build.sourceDirectory
- * 
+ *
  * @author <a href="mailto:jason@maven.org">Jason van Zyl </a>
- * @version $Id: ReflectionValueExtractor.java,v 1.2 2005/03/01 07:05:33 brett
+ * @version $Id$
- *          Exp $
  */
 public class ReflectionValueExtractor
 {
-    private static Class[] args = new Class[0];
+    private static Class[] args = new Class[ 0 ];
 
-    private static Object[] params = new Object[0];
+    private static Object[] params = new Object[ 0 ];
 
     private static ClassMap classMap;
 
@@ -48,7 +46,8 @@ public class ReflectionValueExtractor
     }
 
     // TODO: don't throw Exception
-    public static Object evaluate( String expression, Object root ) throws Exception
+    public static Object evaluate( String expression, Object root )
+        throws Exception
     {
         // ----------------------------------------------------------------------
         // Remove the leading "project" token
@@ -75,6 +74,11 @@ public class ReflectionValueExtractor
 
             Method method = classMap.findMethod( methodName, args );
 
+            if ( method == null )
+            {
+                return null;
+            }
+
             value = method.invoke( value, params );
         }
 
@@ -88,8 +92,10 @@ public class ReflectionValueExtractor
         if ( classMap == null )
         {
             classMap = new ClassMap( clazz );
+
+            classMaps.put( clazz, classMap );
         }
 
         return classMap;
     }
-}
+}

maven-core/src/test/java/org/apache/maven/project/interpolation/RegexBasedModelInterpolatorTest.java

@@ -16,17 +16,18 @@ package org.apache.maven.project.interpolation;
  * limitations under the License.
  */
 
-import junit.framework.TestCase;
 import org.apache.maven.model.Dependency;
 import org.apache.maven.model.Model;
 
+import junit.framework.TestCase;
+
 /**
  * @author jdcasey
+ * @version $Id$
  */
 public class RegexBasedModelInterpolatorTest
     extends TestCase
 {
-
     public void testShouldInterpolateDependencyVersionToSetSameAsProjectVersion()
         throws ModelInterpolationException
     {
@@ -75,5 +76,4 @@ public class RegexBasedModelInterpolatorTest
 
         assertEquals( "foo-3.8.1", ( (Dependency) out.getDependencies().get( 0 ) ).getVersion() );
     }
-
+}
-}

maven-core/src/test/java/org/apache/maven/util/introspection/ReflectionValueExtractorTest.java

@@ -33,15 +33,11 @@ public class ReflectionValueExtractorTest
 {
     private MavenProject project;
 
-    private MavenProjectBuilder builder;
-
     protected void setUp()
         throws Exception
     {
         super.setUp();
 
-        builder = (MavenProjectBuilder) lookup( MavenProjectBuilder.ROLE );
-
         File f = getFileForClasspathResource( "pom.xml" );
 
         project = getProject( f );
@@ -88,4 +84,10 @@ public class ReflectionValueExtractorTest
 
         assertNotNull( build );
     }
+
+    public void testValueExtractorWithAInvalidExpression()
+        throws Exception
+    {
+        assertNull( ReflectionValueExtractor.evaluate( "project.foo", project ) );
+    }
 }