Configure the maven Checkstyle plugin with the Sun Java code style convention.

To generate all site reports (including Checkstyle):
  mvn site
After that, use the following command to generate only the Checkstyle report:
  mvn checkstyle:checkstyle

The report is generated in the following file:

  target/site/checkstyle.html

The Apache Maven Checkstyle plugin URL is:
http://maven.apache.org/plugins/maven-checkstyle-plugin/
diff --git a/pom.xml b/pom.xml
index 61e6452..5b8df0c 100644
--- a/pom.xml
+++ b/pom.xml
@@ -37,6 +37,15 @@
   <build>
     <plugins>
       <plugin>
+	<!-- Note: the checkstyle configuration is also in the reporting section -->
+	<groupId>org.apache.maven.plugins</groupId>
+	<artifactId>maven-checkstyle-plugin</artifactId>
+	<version>2.11</version>
+	<configuration>
+	  <configLocation>conf/checkstyle/sun_checks.xml</configLocation>
+	</configuration>
+      </plugin>
+      <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-install-plugin</artifactId>
         <version>2.3.1</version>
@@ -215,6 +224,27 @@
           <locale>en</locale>
         </configuration>
       </plugin>
+      <plugin>
+	<!-- Note: the checkstyle configuration is also in the build section -->
+	<groupId>org.apache.maven.plugins</groupId>
+	<artifactId>maven-checkstyle-plugin</artifactId>
+	<version>2.11</version>
+	<configuration>
+	  <configLocation>conf/checkstyle/sun_checks.xml</configLocation>
+	</configuration>
+	<reportSets>
+	  <reportSet>
+	    <reports>
+	      <report>checkstyle</report>
+	    </reports>
+	  </reportSet>
+	</reportSets>
+      </plugin>
+      <plugin>
+	<groupId>org.apache.maven.plugins</groupId>
+	<artifactId>maven-jxr-plugin</artifactId>
+	<version>2.3</version>
+    </plugin>
     </plugins>
   </reporting>
   <dependencies>