[MJAR-276] don't log useless warning when jar creation is forced and directory does not exist
diff --git a/src/main/java/org/apache/maven/plugins/jar/AbstractJarMojo.java b/src/main/java/org/apache/maven/plugins/jar/AbstractJarMojo.java
index 68da0ec..d7b298f 100644
--- a/src/main/java/org/apache/maven/plugins/jar/AbstractJarMojo.java
+++ b/src/main/java/org/apache/maven/plugins/jar/AbstractJarMojo.java
@@ -266,7 +266,10 @@
             File contentDirectory = getClassesDirectory();
             if ( !contentDirectory.exists() )
             {
-                getLog().warn( "JAR will be empty - no content was marked for inclusion!" );
+                if ( !forceCreation )
+                {
+                    getLog().warn( "JAR will be empty - no content was marked for inclusion!" );
+                }
             }
             else
             {