Apply spotless

Pretty much same scheme as in Maven project:
* check runs in build and will fail it if not properly formatted
* mvn spotless:apply to format (or -P format)

.gitignore

@@ -1,5 +1,8 @@
 target/
-.project
 .classpath
-.settings/
-bin
+.project
+.settings
+*.iml
+.idea
+out/
+.DS_Store

pom.xml

@@ -16,8 +16,8 @@
   <version>53-SNAPSHOT</version>
   <packaging>pom</packaging>
   <name>Takari</name>
-  <url>http://takari.io</url>
   <description>Takari: The future of software delivery.</description>
+  <url>http://takari.io</url>
 
   <licenses>
     <license>
@@ -56,6 +56,13 @@
     </developer>
   </developers>
 
+  <scm>
+    <connection>scm:git:[email protected]:takari/takari-pom.git</connection>
+    <developerConnection>scm:git:[email protected]:takari/takari-pom.git</developerConnection>
+    <tag>HEAD</tag>
+    <url>http://github.com/takari/takari-pom</url>
+  </scm>
+
   <distributionManagement>
     <repository>
       <id>sonatype.releases</id>
@@ -103,40 +110,7 @@
     <maven.compiler.target>${takari.javaSourceVersion}</maven.compiler.target>
   </properties>
 
-  <scm>
-    <connection>scm:git:[email protected]:takari/takari-pom.git</connection>
-    <developerConnection>scm:git:[email protected]:takari/takari-pom.git</developerConnection>
-    <url>http://github.com/takari/takari-pom</url>
-    <tag>HEAD</tag>
-  </scm>
-
   <build>
-    <plugins>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-enforcer-plugin</artifactId>
-        <executions>
-          <execution>
-            <id>enforce-maven</id>
-            <goals>
-              <goal>enforce</goal>
-            </goals>
-            <configuration>
-              <rules>
-                <requireMavenVersion>
-                  <version>[3.6.3,)</version>
-                </requireMavenVersion>
-              </rules>
-            </configuration>
-          </execution>
-        </executions>
-      </plugin>
-      <plugin>
-        <groupId>io.takari.maven.plugins</groupId>
-        <artifactId>takari-lifecycle-plugin</artifactId>
-        <extensions>true</extensions>
-      </plugin>
-    </plugins>
     <pluginManagement>
       <plugins>
         <!-- set versions/configuration of common plugins for reproducibility, ordered alphabetically -->
@@ -324,6 +298,45 @@
             </mapping>
           </configuration>
         </plugin>
+        <plugin>
+          <groupId>com.diffplug.spotless</groupId>
+          <artifactId>spotless-maven-plugin</artifactId>
+          <version>2.43.0</version>
+          <configuration>
+            <java>
+              <!-- orders of used formatters are important MPOM-376 -->
+              <!-- eg. palantir override importOrder, so should be first -->
+              <palantirJavaFormat />
+              <removeUnusedImports />
+              <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>
+          <dependencies>
+            <dependency>
+              <groupId>org.apache.maven.shared</groupId>
+              <artifactId>maven-shared-resources</artifactId>
+              <version>5</version>
+            </dependency>
+          </dependencies>
+          <executions>
+            <execution>
+              <goals>
+                <goal>${spotless.action}</goal>
+              </goals>
+              <phase>process-sources</phase>
+            </execution>
+          </executions>
+        </plugin>
         <!--This plugin's configuration is used to store Eclipse m2e settings only. It has no influence on the Maven build itself.-->
         <plugin>
           <groupId>org.eclipse.m2e</groupId>
@@ -351,9 +364,61 @@
         </plugin>
       </plugins>
     </pluginManagement>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-enforcer-plugin</artifactId>
+        <executions>
+          <execution>
+            <id>enforce-maven</id>
+            <goals>
+              <goal>enforce</goal>
+            </goals>
+            <configuration>
+              <rules>
+                <requireMavenVersion>
+                  <version>[3.6.3,)</version>
+                </requireMavenVersion>
+              </rules>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+      <plugin>
+        <groupId>io.takari.maven.plugins</groupId>
+        <artifactId>takari-lifecycle-plugin</artifactId>
+        <extensions>true</extensions>
+      </plugin>
+      <plugin>
+        <groupId>com.diffplug.spotless</groupId>
+        <artifactId>spotless-maven-plugin</artifactId>
+      </plugin>
+    </plugins>
   </build>
 
   <profiles>
+    <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>
     <!-- START SNIPPET: release-profile -->
     <profile>
       <id>takari-release</id>