update: compilerArgs

pom.xml

@@ -307,11 +307,10 @@
                     <source>${java.version}</source>
                     <target>${java.version}</target>
                     <encoding>${project.build.sourceEncoding}</encoding>
-                    <compilerArgument>
-                        <extdirs>
-                            ${project.basedir}/libs/dougong
-                        </extdirs>
-                    </compilerArgument>
+                    <compilerArgs>
+                        <arg>-extdirs</arg>
+                        <arg>${project.basedir}/libs/dougong</arg>
+                    </compilerArgs>
                 </configuration>
             </plugin>
         </plugins>