[build] Generate empty javadoc jar to make Sonatype OSS happy

Author: wuchong

fluss-dist/pom.xml

@@ -259,6 +259,25 @@
                     </execution>
                 </executions>
             </plugin>
+
+            <!-- Generate empty javadoc jar to make Sonatype OSS happy -->
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-jar-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>empty-javadoc-jar</id>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>jar</goal>
+                        </goals>
+                        <configuration>
+                            <classifier>javadoc</classifier>
+                            <classesDirectory>${basedir}/javadoc</classesDirectory>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
         </plugins>
     </build>