Add spotless plugin configuration (#169)

* Add spotless plugin configuration
* Use two profiles for spotless
---------

Co-authored-by: Guillaume Nodet <gnodet@gmail.com>

pom.xml

@@ -332,9 +332,11 @@ limitations under the License.
     <plexusDistMgmtSnapshotsUrl>https://oss.sonatype.org/content/repositories/plexus-snapshots</plexusDistMgmtSnapshotsUrl>
     <project.build.outputTimestamp>2023-05-06T22:13:46Z</project.build.outputTimestamp>
     <gpg.useagent>true</gpg.useagent>
+    <spotless-maven-plugin.version>2.36.0</spotless-maven-plugin.version>
     <mavenPluginToolsVersion>3.9.0</mavenPluginToolsVersion>
     <mavenFluidoSkinVersion>1.11.2</mavenFluidoSkinVersion>
     <junit5Version>5.9.3</junit5Version>
+    <spotless.action>check</spotless.action>
   </properties>
 
   <dependencyManagement>
@@ -424,7 +426,8 @@ limitations under the License.
           <configuration>
             <quiet>true</quiet>
             <locale>en</locale>
-            <notimestamp>true</notimestamp><!-- avoid noise for svn/gitpubsub -->
+            <!-- avoid noise for svn/gitpubsub -->
+            <notimestamp>true</notimestamp>
           </configuration>
         </plugin>
         <plugin>
@@ -550,6 +553,41 @@ limitations under the License.
             </execution>
           </executions>
         </plugin>
+        <plugin>
+          <groupId>com.diffplug.spotless</groupId>
+          <artifactId>spotless-maven-plugin</artifactId>
+          <version>${spotless-maven-plugin.version}</version>
+          <configuration>
+            <java>
+              <!-- orders of used formatters are important -->
+              <!-- eg. palantir override importOrder, so should be first -->
+              <palantirJavaFormat />
+              <removeUnusedImports />
+              <importOrder>
+                <order>javax,java,,\#</order>
+              </importOrder>
+            </java>
+            <pom>
+              <sortPom>
+                <expandEmptyElements>false</expandEmptyElements>
+                <!-- https://issues.apache.org/jira/browse/MRELEASE-1111 -->
+                <spaceBeforeCloseEmptyElement>true</spaceBeforeCloseEmptyElement>
+              </sortPom>
+            </pom>
+            <upToDateChecking>
+              <enabled>true</enabled>
+            </upToDateChecking>
+          </configuration>
+          <executions>
+            <execution>
+              <id>spotless-check</id>
+              <goals>
+                <goal>${spotless.action}</goal>
+              </goals>
+              <phase>process-sources</phase>
+            </execution>
+          </executions>
+        </plugin>
       </plugins>
     </pluginManagement>
     <plugins>
@@ -641,18 +679,6 @@ limitations under the License.
             <groupId>org.apache.maven.plugins</groupId>
             <artifactId>maven-surefire-report-plugin</artifactId>
           </plugin>
-          <plugin>
-            <groupId>org.apache.maven.plugins</groupId>
-            <artifactId>maven-checkstyle-plugin</artifactId>
-            <reportSets>
-              <reportSet>
-                <id>default</id>
-                <reports>
-                  <report>checkstyle</report>
-                </reports>
-              </reportSet>
-            </reportSets>
-          </plugin>
           <plugin>
             <groupId>org.apache.maven.plugins</groupId>
             <artifactId>maven-pmd-plugin</artifactId>
@@ -764,5 +790,57 @@ limitations under the License.
         </plugins>
       </build>
     </profile>
+
+    <profile>
+      <id>java11+</id>
+      <activation>
+        <jdk>[11,)</jdk>
+      </activation>
+
+      <properties>
+        <maven.compiler.release>${javaVersion}</maven.compiler.release>
+        <!-- configuration for checkstyle to use with spotless -->
+        <checkstyle.spotless.config>config/maven_checks_nocodestyle.xml</checkstyle.spotless.config>
+      </properties>
+
+      <build>
+        <!--- newer versions of plugins requires JDK 11 -->
+        <plugins>
+          <plugin>
+            <groupId>com.diffplug.spotless</groupId>
+            <artifactId>spotless-maven-plugin</artifactId>
+          </plugin>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-checkstyle-plugin</artifactId>
+            <configuration>
+              <configLocation>${checkstyle.spotless.config}</configLocation>
+            </configuration>
+          </plugin>
+        </plugins>
+      </build>
+    </profile>
+    <profile>
+      <id>format-check</id>
+      <activation>
+        <property>
+          <name>!format</name>
+        </property>
+      </activation>
+      <properties>
+        <spotless.action>check</spotless.action>
+      </properties>
+    </profile>
+    <profile>
+      <id>format</id>
+      <activation>
+        <property>
+          <name>format</name>
+        </property>
+      </activation>
+      <properties>
+        <spotless.action>apply</spotless.action>
+      </properties>
+    </profile>
   </profiles>
 </project>