Ignore PMD violations in generated Thrift source (#325)

All but one violation were in code generated by the Thrift compiler.
Some of them were excluded specifically using PMD exclusion rules, but
the remaining ones refer to inner classes, which don't seem to be
affected by exclusion rules.

Co-authored-by: Andre Caron <[email protected]>

Author: AndreLouisCaron

flume-ng-legacy-sources/flume-thrift-source/exclude-pmd.properties

@@ -0,0 +1,3 @@
+com.cloudera.flume.handlers.thrift.EventStatus=UnnecessaryModifier
+com.cloudera.flume.handlers.thrift.Priority=UnnecessaryModifier
+com.cloudera.flume.handlers.thrift.ThriftFlumeEvent=UnnecessaryFullyQualifiedName,UselessParentheses

flume-ng-legacy-sources/flume-thrift-source/pom.xml

@@ -31,9 +31,14 @@ limitations under the License.
   <name>Flume legacy Thrift Source</name>
 
   <properties>
-    <!-- TODO fix spotbugs/pmd violations -->
-    <spotbugs.maxAllowedViolations>38</spotbugs.maxAllowedViolations>
-    <pmd.maxAllowedViolations>119</pmd.maxAllowedViolations>
+    <!-- TODO fix spotbugs violations -->
+    <spotbugs.maxAllowedViolations>37</spotbugs.maxAllowedViolations>
+    <!-- PMD violations come from code generated by the Thrift compiler.
+         We cannot seem to be able to match inner classes (with a `$` in them)
+         using the patterns in `exclude-pmd.properties`, so we cannot exclude
+         the remaining violations and we must live with them. -->
+    <pmd.maxAllowedViolations>91</pmd.maxAllowedViolations>
+    <pmd.excludeFromFailureFile>${basedir}/exclude-pmd.properties</pmd.excludeFromFailureFile>
   </properties>
 
   <profiles>

flume-ng-legacy-sources/flume-thrift-source/src/main/java/org/apache/flume/source/thriftLegacy/ThriftLegacySource.java

@@ -99,7 +99,6 @@ public void append(ThriftFlumeEvent evt ) {
       }
 
       counterGroup.incrementAndGet("rpc.successful");
-      return;
     }
 
     public void close() {

pom.xml

@@ -534,6 +534,7 @@ limitations under the License.
               <exclude>**/derby.log</exclude>
               <exclude>**/metastore_db/</exclude>
               <exclude>.mvn/**</exclude>
+              <exclude>**/exclude-pmd.properties</exclude>
             </excludes>
             <consoleOutput>true</consoleOutput>
           </configuration>