pmd: fix #1027 PMD Ant: java.lang.ClassCastException

pmd/etc/changelog.txt

@@ -11,6 +11,7 @@ Fixed bug  997: Rule NonThreadSafeSingleton gives analysis problem
 Fixed bug  999: Law of Demeter: False positives and negatives
 Fixed bug 1002: False +: FinalFieldCouldBeStatic on inner class
 Fixed bug 1005: False + for ConstructorCallsOverridableMethod - overloaded methods
+Fixed bug 1027: PMD Ant: java.lang.ClassCastException
 Fixed bug 1032: ImmutableField Rule: Private field in inner class gives false positive
 Fixed bug 1064: Exception running PrematureDeclaration
 Fixed bug 1068: CPD fails on broken symbolic links

pmd/src/main/java/net/sourceforge/pmd/ant/PMDTask.java

@@ -289,7 +289,12 @@ public class PMDTask extends Task {
 			log("Using the normal ClassLoader", Project.MSG_VERBOSE);
 		} else {
 			log("Using the AntClassLoader", Project.MSG_VERBOSE);
-			configuration.setClassLoader(new AntClassLoader(getProject(), classpath));
+			// must be true, otherwise you'll get ClassCastExceptions as classes are loaded twice
+			// and exist in multiple class loaders
+			boolean parentFirst = true;
+			configuration.setClassLoader(
+			        new AntClassLoader(Thread.currentThread().getContextClassLoader(), getProject(),
+			                classpath, parentFirst));
 		}
 		try {
 			/*

pmd/src/test/java/net/sourceforge/pmd/ant/PMDTaskTest.java

@@ -110,7 +110,12 @@ public class PMDTaskTest extends BuildFileTest {
         assertOutputContaining("Avoid using global variables");
         assertOutputContaining("Use ===/!== to compare with true/false or Numbers");
     }
-    
+
+    @Test
+    public void testClasspath() {
+        executeTarget("testClasspath");
+    }
+
     public static junit.framework.Test suite() {
         return new junit.framework.JUnit4TestAdapter(PMDTaskTest.class);
     }

pmd/src/test/resources/net/sourceforge/pmd/ant/classpathtest/ruleset.xml

@@ -0,0 +1,86 @@
+<?xml version="1.0"?>
+
+<ruleset name="Basic"
+    xmlns="http://pmd.sourceforge.net/ruleset/2.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://pmd.sourceforge.net/ruleset/2.0.0 http://pmd.sourceforge.net/ruleset_2_0_0.xsd">
+  <description>
+The Basic ruleset contains a collection of good practices which should be followed.
+  </description>
+
+	<rule name="JumbledIncrementer"
+    	  language="java"
+    	  since="1.0"
+          message="Avoid modifying an outer loop incrementer in an inner loop for update expression"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          externalInfoUrl="${pmd.website.baseurl}/rules/java/basic.html#JumbledIncrementer">
+     <description>
+Avoid jumbled loop incrementers - its usually a mistake, and is confusing even if intentional.
+     </description>
+     <priority>3</priority>
+     <properties>
+         <property name="xpath">
+             <value>
+ <![CDATA[
+//ForStatement
+ [
+  ForUpdate/StatementExpressionList/StatementExpression/PostfixExpression/PrimaryExpression/PrimaryPrefix/Name/@Image
+  =
+  ancestor::ForStatement/ForInit//VariableDeclaratorId/@Image
+ ]
+ ]]>
+             </value>
+         </property>
+     </properties>
+     <example>
+ <![CDATA[
+public class JumbledIncrementerRule1 {
+	public void foo() {
+		for (int i = 0; i < 10; i++) {			// only references 'i'
+			for (int k = 0; k < 20; i++) {		// references both 'i' and 'k'
+				System.out.println("Hello");
+			}
+		}
+	}
+}
+ ]]>
+     </example>
+     </rule>
+
+    <rule name="OverrideBothEqualsAndHashcode"
+          language="java"
+          since="0.4"
+          message="Ensure you override both equals() and hashCode()"
+          class="net.sourceforge.pmd.lang.java.rule.basic.OverrideBothEqualsAndHashcodeRule"
+          externalInfoUrl="${pmd.website.baseurl}/rules/java/basic.html#OverrideBothEqualsAndHashcode">
+      <description>
+Override both public boolean Object.equals(Object other), and public int Object.hashCode(), or override neither.  Even if you are inheriting a hashCode() from a parent class, consider implementing hashCode and explicitly delegating to your superclass.
+      </description>
+      <priority>3</priority>
+      <example>
+  <![CDATA[
+public class Bar {		// poor, missing a hashcode() method
+	public boolean equals(Object o) {
+      // do some comparison
+	}
+}
+
+public class Baz {		// poor, missing an equals() method
+	public int hashCode() {
+      // return some hash value
+	}
+}
+
+public class Foo {		// perfect, both methods provided
+	public boolean equals(Object other) {
+      // do some comparison
+	}
+	public int hashCode() {
+      // return some hash value
+	}
+}
+ ]]>
+      </example>
+    </rule>
+
+</ruleset>

pmd/src/test/resources/net/sourceforge/pmd/ant/xml/pmdtasktest.xml

@@ -127,4 +127,15 @@
 			</fileset>
 		</pmd>
 	</target>
+
+    <target name="testClasspath">
+        <pmd>
+            <ruleset>classpathtest/ruleset.xml</ruleset>
+            <classpath>
+                <pathelement path="${pmd.home}/target/classes"/>
+                <pathelement path="${pmd.home}/target/test-classes"/>
+                <pathelement path="${pmd.home}/target/test-classes/net/sourceforge/pmd/ant"/>
+            </classpath>
+        </pmd>
+    </target>
 </project>