Enable several more checkstyle modules

* Enable checkstyle ParenPadCheck
* Enable checkstyle EmptyLineSeparator
* Enable checkstyle TypecastParenPad

airsonic-main/src/main/java/org/airsonic/player/ajax/TransferService.java

@@ -25,6 +25,7 @@ import org.directwebremoting.WebContextFactory;
 import org.springframework.stereotype.Service;
 
 import javax.servlet.http.HttpSession;
+
 /**
  * Provides AJAX-enabled services for retrieving the status of ongoing transfers.
  * This class is used by the DWR framework (http://getahead.ltd.uk/dwr/).

airsonic-main/src/main/java/org/airsonic/player/controller/ControllerUtils.java

@@ -15,7 +15,7 @@ public class ControllerUtils {
 
         String path = (String) request.getAttribute(
                 HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE);
-        String bestMatchPattern = (String ) request.getAttribute(HandlerMapping.BEST_MATCHING_PATTERN_ATTRIBUTE);
+        String bestMatchPattern = (String) request.getAttribute(HandlerMapping.BEST_MATCHING_PATTERN_ATTRIBUTE);
 
         AntPathMatcher apm = new AntPathMatcher();
 

airsonic-main/src/main/java/org/airsonic/player/i18n/LocaleResolver.java

@@ -32,6 +32,7 @@ import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Locale;
 import java.util.Set;
+
 /**
  * Locale resolver implementation which returns the locale selected in the settings.
  *

airsonic-main/src/main/java/org/airsonic/player/service/PlayerService.java

@@ -341,7 +341,7 @@ public class PlayerService {
 
         // Create player if necessary.
         Player player = new Player();
-        if (request != null ) {
+        if (request != null) {
             player.setIpAddress(request.getRemoteAddr());
         }
         player.setUsername(User.USERNAME_GUEST);

airsonic-main/src/main/java/org/airsonic/player/service/SettingsService.java

@@ -252,7 +252,7 @@ public class SettingsService {
 
     private void removeObsoleteProperties() {
 
-        OBSOLETE_KEYS.forEach( oKey -> {
+        OBSOLETE_KEYS.forEach(oKey -> {
             if(configurationService.containsKey(oKey)) {
                 LOG.info("Removing obsolete property [" + oKey + ']');
                 configurationService.clearProperty(oKey);

airsonic-main/src/main/java/org/airsonic/player/service/metadata/DefaultMetaDataParser.java

@@ -40,6 +40,7 @@ public class DefaultMetaDataParser extends MetaDataParser {
     public DefaultMetaDataParser(SettingsService settingsService) {
         this.settingsService = settingsService;
     }
+
     /**
      * Parses meta data for the given file.
      *

airsonic-main/src/main/java/org/airsonic/player/util/StringUtil.java

@@ -201,7 +201,7 @@ public final class StringUtil {
         // More than 1 TB?
         if (byteCount >= 1024L * 1024 * 1024 * 1024) {
             NumberFormat teraByteFormat = new DecimalFormat("0.00 TB", new DecimalFormatSymbols(locale));
-            return teraByteFormat.format( byteCount / ((double) 1024 * 1024 * 1024 * 1024));
+            return teraByteFormat.format(byteCount / ((double) 1024 * 1024 * 1024 * 1024));
         }
      
         // More than 1 GB?

checkstyle.xml

@@ -21,13 +21,20 @@
             <property name="separateLineBetweenGroups" value="true"/>
         </module>
         <module name="DefaultComesLast"/>
+        <module name="EmptyLineSeparator">
+            <!-- Enable all except PACKAGE_DEF, METHOD_DEF, VARIABLE_DEF -->
+            <property name="tokens"
+                      value="IMPORT, STATIC_IMPORT, CLASS_DEF, INTERFACE_DEF, ENUM_DEF, STATIC_INIT, INSTANCE_INIT, CTOR_DEF"/>
+        </module>
         <module name="EmptyStatement"/>
         <module name="EqualsAvoidNull"/>
         <module name="EqualsHashCode"/>
         <module name="Indentation"/>
         <module name="InnerAssignment"/>
+        <module name="ParenPadCheck"/>
         <module name="RedundantImport"/>
         <module name="StringLiteralEquality"/>
+        <module name="TypecastParenPad"/>
         <module name="UnusedImports"/>
     </module>
 </module>