Enable additional checkstyles for whitespace

* Enable checkstyle WhitespaceAround
* Enable checkstyle NoWhitespaceBefore
* Enable checkstyle MethodParamPad

airsonic-main/src/main/java/org/airsonic/player/Application.java

@@ -197,7 +197,7 @@ public class Application extends SpringBootServletInitializer implements Embedde
         // specific classes.
         try {
             Class<?> tomcatESCF = Class.forName("org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory");
-            if(tomcatESCF.isInstance(container)) {
+            if (tomcatESCF.isInstance(container)) {
                 LOG.info("Detected Tomcat web server");
                 LOG.debug("Attempting to optimize tomcat");
                 Object tomcatESCFInstance = tomcatESCF.cast(container);
@@ -216,7 +216,7 @@ public class Application extends SpringBootServletInitializer implements Embedde
 
         try {
             Class<?> jettyESCF = Class.forName("org.springframework.boot.context.embedded.jetty.JettyEmbeddedServletContainerFactory");
-            if(jettyESCF.isInstance(container)) {
+            if (jettyESCF.isInstance(container)) {
                 LOG.warn("Detected Jetty web server. Here there be dragons.");
             }
         } catch (NoClassDefFoundError | ClassNotFoundException e) {

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

@@ -745,7 +745,7 @@ public class PlayQueueService {
         List<PlayQueueInfo.Entry> entries = new ArrayList<>();
         for (InternetRadioSource streamSource: internetRadioService.getInternetRadioSources(radio)) {
             // Fake entry id so that the source can be selected in the UI
-            Integer streamId = -(1+entries.size());
+            Integer streamId = -(1 + entries.size());
             Integer streamTrackNumber = entries.size();
             String streamUrl = streamSource.getStreamUrl();
             entries.add(new PlayQueueInfo.Entry(

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

@@ -88,7 +88,7 @@ public class AvatarController implements LastModified {
         if (userSettings.getAvatarScheme() == AvatarScheme.CUSTOM || forceCustom) {
             return settingsService.getCustomAvatar(username);
         }
-        if(userSettings.getAvatarScheme() == AvatarScheme.NONE) {
+        if (userSettings.getAvatarScheme() == AvatarScheme.NONE) {
             return null;
         }
         return settingsService.getSystemAvatar(userSettings.getSystemAvatarId());

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

@@ -11,7 +11,7 @@ import javax.servlet.http.HttpServletRequest;
  */
 public class ControllerUtils {
 
-    public static String extractMatched(final HttpServletRequest request){
+    public static String extractMatched(final HttpServletRequest request) {
 
         String path = (String) request.getAttribute(
                 HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE);

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

@@ -66,7 +66,7 @@ public class DatabaseSettingsController {
         if (!bindingResult.hasErrors()) {
             settingsService.resetDatabaseToDefault();
             settingsService.setDatabaseConfigType(command.getConfigType());
-            switch(command.getConfigType()) {
+            switch (command.getConfigType()) {
                 case EMBED:
                     settingsService.setDatabaseConfigEmbedDriver(command.getEmbedDriver());
                     settingsService.setDatabaseConfigEmbedPassword(command.getEmbedPassword());
@@ -80,7 +80,7 @@ public class DatabaseSettingsController {
                 default:
                     break;
             }
-            if(command.getConfigType() != DataSourceConfigType.LEGACY) {
+            if (command.getConfigType() != DataSourceConfigType.LEGACY) {
                 settingsService.setDatabaseMysqlVarcharMaxlength(command.getMysqlVarcharMaxlength());
                 settingsService.setDatabaseUsertableQuote(command.getUsertableQuote());
             }

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

@@ -72,7 +72,7 @@ public class ExternalPlayerController {
         String shareName = ControllerUtils.extractMatched(request);
         LOG.debug("Share name is {}", shareName);
 
-        if(StringUtils.isBlank(shareName)) {
+        if (StringUtils.isBlank(shareName)) {
             LOG.warn("Could not find share with shareName " + shareName);
             response.sendError(HttpServletResponse.SC_NOT_FOUND);
             return null;
@@ -102,7 +102,7 @@ public class ExternalPlayerController {
     private List<MediaFileWithUrlInfo> getSongs(HttpServletRequest request, Share share, Player player) throws IOException {
         Date expires = null;
         Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
-        if(authentication instanceof JWTAuthenticationToken) {
+        if (authentication instanceof JWTAuthenticationToken) {
             DecodedJWT token = jwtSecurityService.verify((String) authentication.getCredentials());
             expires = token.getExpiresAt();
         }

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

@@ -101,7 +101,7 @@ public class HelpController {
             List<String> lines = new ArrayList<>(LOG_LINES_TO_SHOW);
             ReversedLinesFileReader reader = new ReversedLinesFileReader(logFile, Charset.defaultCharset());
             String current;
-            while((current = reader.readLine()) != null) {
+            while ((current = reader.readLine()) != null) {
                 if (lines.size() >= LOG_LINES_TO_SHOW) {
                     break;
                 }

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

@@ -65,7 +65,7 @@ public class InternetRadioSettingsController {
 
         String error = handleParameters(request);
         Map<String, Object> map = new HashMap<>();
-        if(error == null) {
+        if (error == null) {
             redirectAttributes.addFlashAttribute("settings_toast", true);
             redirectAttributes.addFlashAttribute("settings_reload", true);
         }

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

@@ -39,9 +39,9 @@ public class LoginController {
         if (username != null && password != null) {
             username = StringUtil.urlEncode(username);
             password = StringUtil.urlEncode(password);
-            return new ModelAndView(new RedirectView("/login?"+
+            return new ModelAndView(new RedirectView("/login?" +
-                    UsernamePasswordAuthenticationFilter.SPRING_SECURITY_FORM_USERNAME_KEY+"=" + username +
+                    UsernamePasswordAuthenticationFilter.SPRING_SECURITY_FORM_USERNAME_KEY + "=" + username +
-                    "&"+UsernamePasswordAuthenticationFilter.SPRING_SECURITY_FORM_PASSWORD_KEY+"=" + password
+                    "&" + UsernamePasswordAuthenticationFilter.SPRING_SECURITY_FORM_PASSWORD_KEY + "=" + password
             ));
         }
 

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

@@ -104,7 +104,7 @@ public class MainController  {
 
         int userPaginationPreference = userSettings.getPaginationSize();
 
-        if(userPaginationPreference <= 0) {
+        if (userPaginationPreference <= 0) {
             showAll = true;
         }
 
@@ -175,8 +175,8 @@ public class MainController  {
 
     private <T> boolean trimToSize(Boolean showAll, List<T> list, int userPaginationPreference) {
         boolean trimmed = false;
-        if(!BooleanUtils.isTrue(showAll)) {
+        if (!BooleanUtils.isTrue(showAll)) {
-            if(list.size() > userPaginationPreference) {
+            if (list.size() > userPaginationPreference) {
                 trimmed = true;
                 list.subList(userPaginationPreference, list.size()).clear();
             }

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

@@ -74,7 +74,7 @@ public class RecoverController {
                 map.put("error", "recover.error.noemail");
             } else {
                 StringBuilder sb = new StringBuilder(PASSWORD_LENGTH);
-                for(int i=0; i<PASSWORD_LENGTH; i++) {
+                for (int i = 0; i < PASSWORD_LENGTH; i++) {
                     int index = random.nextInt(SYMBOLS.length());
                     sb.append(SYMBOLS.charAt(index));
                 }

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

@@ -149,7 +149,7 @@ public class SubsonicRESTController {
     public void handleMissingRequestParam(HttpServletRequest request,
                                           HttpServletResponse response,
                                           MissingServletRequestParameterException exception) throws Exception {
-        error(request, response, ErrorCode.MISSING_PARAMETER, "Required param ("+exception.getParameterName()+") is missing");
+        error(request, response, ErrorCode.MISSING_PARAMETER, "Required param (" + exception.getParameterName() + ") is missing");
     }
 
     @RequestMapping(value = "/ping")

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

@@ -68,7 +68,7 @@ public class TranscodingSettingsController {
     @PostMapping
     public String doPost(HttpServletRequest request, RedirectAttributes redirectAttributes) throws Exception {
         String error = handleParameters(request, redirectAttributes);
-        if(error != null) {
+        if (error != null) {
             redirectAttributes.addFlashAttribute("settings_toast", true);
         }
         redirectAttributes.addFlashAttribute("error", error);
@@ -127,7 +127,7 @@ public class TranscodingSettingsController {
             } else {
                 transcodingService.createTranscoding(transcoding);
             }
-            if(error != null) {
+            if (error != null) {
                 redirectAttributes.addAttribute("newTranscoding", transcoding);
                 return error;
             }

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

@@ -75,7 +75,7 @@ public class UserSettingsController {
     @GetMapping
     protected String displayForm(HttpServletRequest request, Model model) throws Exception {
         UserSettingsCommand command;
-        if(!model.containsAttribute("command")) {
+        if (!model.containsAttribute("command")) {
             command = new UserSettingsCommand();
 
             User user = getUser(request);
@@ -132,7 +132,7 @@ public class UserSettingsController {
     @PostMapping
     protected String doSubmitAction(@ModelAttribute("command") @Validated UserSettingsCommand command, BindingResult bindingResult, RedirectAttributes redirectAttributes) throws Exception {
 
-        if(!bindingResult.hasErrors()) {
+        if (!bindingResult.hasErrors()) {
             if (command.isDeleteUser()) {
                 deleteUser(command);
             } else if (command.isNewUser()) {
@@ -154,7 +154,7 @@ public class UserSettingsController {
     private Integer getUserIndex(UserSettingsCommand command) {
         List<User> allUsers = securityService.getAllUsers();
         for (int i = 0; i < allUsers.size(); i++) {
-            if(StringUtils.equalsIgnoreCase(allUsers.get(i).getUsername(), command.getUsername())) {
+            if (StringUtils.equalsIgnoreCase(allUsers.get(i).getUsername(), command.getUsername())) {
                 return i;
             }
         }

airsonic-main/src/main/java/org/airsonic/player/dao/LegacyHsqlDaoHelper.java

@@ -49,9 +49,9 @@ public class LegacyHsqlDaoHelper extends GenericDaoHelper {
 
         } finally {
             try {
-                if(conn != null)
+                if (conn != null)
                     conn.close();
-            } catch(Exception ex) {
+            } catch (Exception ex) {
                 ex.printStackTrace();
             }
         }

airsonic-main/src/main/java/org/airsonic/player/dao/MediaFileDao.java

@@ -403,7 +403,7 @@ public class MediaFileDao extends AbstractDao {
         args.put("type", MediaFile.MediaType.MUSIC.name());
         args.put("folders", MusicFolder.toPathList(musicFolders));
         return namedQueryOne("select " + QUERY_COLUMNS + " from media_file where artist = :artist " +
-                             "and title = :title and type = :type and present and folder in (:folders)" ,
+                             "and title = :title and type = :type and present and folder in (:folders)",
                              rowMapper, args);
     }
 

airsonic-main/src/main/java/org/airsonic/player/dao/PlayerDao.java

@@ -97,7 +97,7 @@ public class PlayerDao extends AbstractDao {
     @Transactional
     public void createPlayer(Player player) {
         Integer existingMax = getJdbcTemplate().queryForObject("select max(id) from player", Integer.class);
-        if(existingMax == null) {
+        if (existingMax == null) {
             existingMax = 0;
         }
         int id = existingMax + 1;

airsonic-main/src/main/java/org/airsonic/player/dao/TranscodingDao.java

@@ -88,7 +88,7 @@ public class TranscodingDao extends AbstractDao {
     @Transactional
     public void createTranscoding(Transcoding transcoding) {
         Integer existingMax = getJdbcTemplate().queryForObject("select max(id) from transcoding2", Integer.class);
-        if(existingMax == null) {
+        if (existingMax == null) {
             existingMax = 0;
         }
         transcoding.setId(existingMax + 1);

airsonic-main/src/main/java/org/airsonic/player/dao/UserDao.java

@@ -84,19 +84,19 @@ public class UserDao extends AbstractDao {
      */
     public User getUserByName(String username, boolean caseSensitive) {
         String sql;
-        if(caseSensitive) {
+        if (caseSensitive) {
             sql = "select " + USER_COLUMNS + " from " + getUserTable() + " where username=?";
         } else {
             sql = "select " + USER_COLUMNS + " from " + getUserTable() + " where UPPER(username)=UPPER(?)";
         }
         List<User> users = query(sql, userRowMapper, username);
         User user = null;
-        if(users.size() == 1) {
+        if (users.size() == 1) {
             user = users.iterator().next();
         } else if (users.size() > 1) {
             throw new RuntimeException("Too many matching users");
         }
-        if(user != null) {
+        if (user != null) {
             readRoles(user);
         }
         return user;
@@ -111,7 +111,7 @@ public class UserDao extends AbstractDao {
     public User getUserByEmail(String email) {
         String sql = "select " + USER_COLUMNS + " from " + getUserTable() + " where email=?";
         User user = queryOne(sql, userRowMapper, email);
-        if(user != null) {
+        if (user != null) {
             readRoles(user);
         }
         return user;

airsonic-main/src/main/java/org/airsonic/player/domain/Version.java

@@ -54,7 +54,7 @@ public class Version implements Comparable<Version> {
      * @return Whether this object is equals to another.
      */
     public boolean equals(Object o) {
-        if(o instanceof Version) {
+        if (o instanceof Version) {
             return internalVersion.equals(((Version)o).internalVersion);
         } else {
             return false;

airsonic-main/src/main/java/org/airsonic/player/security/GlobalSecurityConfig.java

@@ -64,7 +64,7 @@ public class GlobalSecurityConfig extends GlobalAuthenticationConfigurerAdapter
         }
         auth.userDetailsService(securityService);
         String jwtKey = settingsService.getJWTKey();
-        if(StringUtils.isBlank(jwtKey)) {
+        if (StringUtils.isBlank(jwtKey)) {
             logger.warn("Generating new jwt key");
             jwtKey = JWTSecurityService.generateKey();
             settingsService.setJWTKey(jwtKey);

airsonic-main/src/main/java/org/airsonic/player/security/JWTAuthenticationProvider.java

@@ -34,7 +34,7 @@ public class JWTAuthenticationProvider implements AuthenticationProvider {
     @Override
     public Authentication authenticate(Authentication auth) throws AuthenticationException {
         JWTAuthenticationToken authentication = (JWTAuthenticationToken) auth;
-        if(authentication.getCredentials() == null || !(authentication.getCredentials() instanceof String)) {
+        if (authentication.getCredentials() == null || !(authentication.getCredentials() instanceof String)) {
             logger.error("Credentials not present");
             return null;
         }
@@ -44,9 +44,9 @@ public class JWTAuthenticationProvider implements AuthenticationProvider {
         authentication.setAuthenticated(true);
 
         // TODO:AD This is super unfortunate, but not sure there is a better way when using JSP
-        if(StringUtils.contains(authentication.getRequestedPath(), "/WEB-INF/jsp/")) {
+        if (StringUtils.contains(authentication.getRequestedPath(), "/WEB-INF/jsp/")) {
             logger.warn("BYPASSING AUTH FOR WEB-INF page");
-        } else if(!roughlyEqual(path.asString(), authentication.getRequestedPath())) {
+        } else if (!roughlyEqual(path.asString(), authentication.getRequestedPath())) {
             throw new InsufficientAuthenticationException("Credentials not valid for path " + authentication
                     .getRequestedPath() + ". They are valid for " + path.asString());
         }
@@ -59,7 +59,7 @@ public class JWTAuthenticationProvider implements AuthenticationProvider {
 
     private static boolean roughlyEqual(String expectedRaw, String requestedPathRaw) {
         logger.debug("Comparing expected [{}] vs requested [{}]", expectedRaw, requestedPathRaw);
-        if(StringUtils.isEmpty(expectedRaw)) {
+        if (StringUtils.isEmpty(expectedRaw)) {
             logger.debug("False: empty expected");
             return false;
         }
@@ -67,7 +67,7 @@ public class JWTAuthenticationProvider implements AuthenticationProvider {
             UriComponents expected = UriComponentsBuilder.fromUriString(expectedRaw).build();
             UriComponents requested = UriComponentsBuilder.fromUriString(requestedPathRaw).build();
 
-            if(!Objects.equals(expected.getPath(), requested.getPath())) {
+            if (!Objects.equals(expected.getPath(), requested.getPath())) {
                 logger.debug("False: expected path [{}] does not match requested path [{}]",
                         expected.getPath(), requested.getPath());
                 return false;
@@ -76,7 +76,7 @@ public class JWTAuthenticationProvider implements AuthenticationProvider {
             MapDifference<String, List<String>> difference = Maps.difference(expected.getQueryParams(),
                     requested.getQueryParams());
 
-            if(!difference.entriesDiffering().isEmpty() ||
+            if (!difference.entriesDiffering().isEmpty() ||
                     !difference.entriesOnlyOnLeft().isEmpty() ||
                     difference.entriesOnlyOnRight().size() != 1 ||
                     difference.entriesOnlyOnRight().get(JWTSecurityService.JWT_PARAM_NAME) == null) {
@@ -84,7 +84,7 @@ public class JWTAuthenticationProvider implements AuthenticationProvider {
                 return false;
             }
 
-        } catch(Exception e) {
+        } catch (Exception e) {
             logger.warn("Exception encountered while comparing paths", e);
             return false;
         }

airsonic-main/src/main/java/org/airsonic/player/security/JWTRequestParameterProcessingFilter.java

@@ -33,7 +33,7 @@ public class JWTRequestParameterProcessingFilter implements Filter {
 
     public Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response) throws AuthenticationException, IOException, ServletException {
         Optional<JWTAuthenticationToken> token = findToken(request);
-        if(token.isPresent()) {
+        if (token.isPresent()) {
             return authenticationManager.authenticate(token.get());
         }
         throw new AuthenticationServiceException("Invalid auth method");
@@ -41,7 +41,7 @@ public class JWTRequestParameterProcessingFilter implements Filter {
 
     private static Optional<JWTAuthenticationToken> findToken(HttpServletRequest request) {
         String token = request.getParameter(JWTSecurityService.JWT_PARAM_NAME);
-        if(!StringUtils.isEmpty(token)) {
+        if (!StringUtils.isEmpty(token)) {
             return Optional.of(new JWTAuthenticationToken(AuthorityUtils.NO_AUTHORITIES, token, request.getRequestURI() + "?" + request.getQueryString()));
         }
         return Optional.empty();
@@ -58,7 +58,7 @@ public class JWTRequestParameterProcessingFilter implements Filter {
         HttpServletRequest request = (HttpServletRequest) req;
         HttpServletResponse response = (HttpServletResponse) resp;
 
-        if(!findToken(request).isPresent()) {
+        if (!findToken(request).isPresent()) {
             chain.doFilter(req, resp);
             return;
         }

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

@@ -28,7 +28,7 @@ public class ApacheCommonsConfigurationService {
 
     public ApacheCommonsConfigurationService() {
         File propertyFile = SettingsService.getPropertyFile();
-        if(!propertyFile.exists()) {
+        if (!propertyFile.exists()) {
             try {
                 FileUtils.touch(propertyFile);
             } catch (IOException e) {

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

@@ -68,7 +68,7 @@ public class NetworkService {
             xForardedHost = xForardedHost.split(",")[0];
         }
 
-        if(!isValidXForwardedHost(xForardedHost)) {
+        if (!isValidXForwardedHost(xForardedHost)) {
             xForardedHost = request.getHeader(X_FORWARDED_SERVER);
 
             // If the request has been through multiple reverse proxies,
@@ -77,7 +77,7 @@ public class NetworkService {
                 xForardedHost = xForardedHost.split(",")[0];
             }
 
-            if(!isValidXForwardedHost(xForardedHost)) {
+            if (!isValidXForwardedHost(xForardedHost)) {
                 throw new RuntimeException("Cannot calculate proxy uri without HTTP header " + X_FORWARDED_HOST);
             }
         }
@@ -86,7 +86,7 @@ public class NetworkService {
         String host = proxyHost.getHost();
         int port = proxyHost.getPort();
         String scheme = request.getHeader(X_FORWARDED_PROTO);
-        if(StringUtils.isBlank(scheme)) {
+        if (StringUtils.isBlank(scheme)) {
             throw new RuntimeException("Scheme not provided");
         }
 

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

@@ -188,7 +188,7 @@ public class PlaylistService {
             throw new Exception("Unsupported playlist " + fileName);
         }
         PlaylistImportHandler importHandler = getImportHandler(inputSpecificPlaylist);
-        LOG.debug("Using "+importHandler.getClass().getSimpleName()+" playlist import handler");
+        LOG.debug("Using " + importHandler.getClass().getSimpleName() + " playlist import handler");
 
         Pair<List<MediaFile>, List<String>> result = importHandler.handle(inputSpecificPlaylist);
 

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

@@ -360,7 +360,7 @@ public class PodcastService {
     private void downloadImage(PodcastChannel channel) {
         InputStream in = null;
         OutputStream out = null;
-        try(CloseableHttpClient client = HttpClients.createDefault()) {
+        try (CloseableHttpClient client = HttpClients.createDefault()) {
             String imageUrl = channel.getImageUrl();
             if (imageUrl == null) {
                 return;

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

@@ -253,7 +253,7 @@ public class SettingsService {
     private void removeObsoleteProperties() {
 
         OBSOLETE_KEYS.forEach(oKey -> {
-            if(configurationService.containsKey(oKey)) {
+            if (configurationService.containsKey(oKey)) {
                 LOG.info("Removing obsolete property [" + oKey + ']');
                 configurationService.clearProperty(oKey);
             }
@@ -269,7 +269,7 @@ public class SettingsService {
         String oldHome = System.getProperty("libresonic.home");
         if (overrideHome != null) {
             home = new File(overrideHome);
-        } else if(oldHome != null) {
+        } else if (oldHome != null) {
             home = new File(oldHome);
         } else {
             boolean isWindows = System.getProperty("os.name", "Windows").toLowerCase().startsWith("windows");
@@ -314,7 +314,7 @@ public class SettingsService {
     }
 
     public void save(boolean updateSettingsChanged) {
-        if(updateSettingsChanged) {
+        if (updateSettingsChanged) {
             removeObsoleteProperties();
             this.setLong(KEY_SETTINGS_CHANGED, System.currentTimeMillis());
         }

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

@@ -413,7 +413,7 @@ public class TranscodingService {
         List<Transcoding> transcodingsForPlayer = getTranscodingsForPlayer(player);
         for (Transcoding transcoding : transcodingsForPlayer) {
             // special case for now as video must have a transcoding
-            if(mediaFile.isVideo() && StringUtils.equalsIgnoreCase(preferredTargetFormat, transcoding.getTargetFormat())) {
+            if (mediaFile.isVideo() && StringUtils.equalsIgnoreCase(preferredTargetFormat, transcoding.getTargetFormat())) {
                 LOG.debug("Detected source to target format match for video");
                 return transcoding;
             }

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

@@ -69,9 +69,9 @@ public class UPnPService {
 
     @PostConstruct
     public void init() {
-        if(settingsService.isDlnaEnabled() || settingsService.isSonosEnabled()) {
+        if (settingsService.isDlnaEnabled() || settingsService.isSonosEnabled()) {
             ensureServiceStarted();
-            if(settingsService.isDlnaEnabled()) {
+            if (settingsService.isDlnaEnabled()) {
                 // Start DLNA media server?
                 setMediaServerEnabled(true);
             }
@@ -86,7 +86,7 @@ public class UPnPService {
 
     public void ensureServiceStarted() {
         running.getAndUpdate(bo -> {
-            if(!bo) {
+            if (!bo) {
                 startService();
                 return true;
             } else {

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

@@ -249,7 +249,7 @@ public class VersionService {
 
         Function<String, Version> convertToVersion = s -> {
             Matcher match = VERSION_REGEX.matcher(s);
-            if(!match.matches()) {
+            if (!match.matches()) {
                 throw new RuntimeException("Unexpected tag format " + s);
             }
             return new Version(match.group(1));

airsonic-main/src/main/java/org/airsonic/player/service/playlist/DefaultPlaylistImportHandler.java

@@ -68,7 +68,7 @@ public class DefaultPlaylistImportHandler implements PlaylistImportHandler {
                         URI uri = media.getSource().getURI();
                         File file = new File(uri);
                         MediaFile mediaFile = mediaFileService.getMediaFile(file);
-                        if(mediaFile != null) {
+                        if (mediaFile != null) {
                             mediaFiles.add(mediaFile);
                         } else {
                             errors.add("Cannot find media file " + file);

airsonic-main/src/main/java/org/airsonic/player/service/playlist/XspfPlaylistImportHandler.java

@@ -34,15 +34,15 @@ public class XspfPlaylistImportHandler implements PlaylistImportHandler {
         Playlist xspfPlaylist = (Playlist) inputSpecificPlaylist;
         xspfPlaylist.getTracks().forEach(track -> {
             MediaFile mediaFile = null;
-            for(StringContainer sc : track.getStringContainers()) {
+            for (StringContainer sc : track.getStringContainers()) {
-                if(sc instanceof Location) {
+                if (sc instanceof Location) {
                     Location location = (Location) sc;
                     try {
                         File file = new File(new URI(location.getText()));
                         mediaFile = mediaFileService.getMediaFile(file);
                     } catch (Exception ignored) {}
 
-                    if(mediaFile == null) {
+                    if (mediaFile == null) {
                         try {
                             File file = new File(sc.getText());
                             mediaFile = mediaFileService.getMediaFile(file);
@@ -50,7 +50,7 @@ public class XspfPlaylistImportHandler implements PlaylistImportHandler {
                     }
                 }
             }
-            if(mediaFile != null) {
+            if (mediaFile != null) {
                 mediaFiles.add(mediaFile);
             } else {
                 String errorMsg = "Could not find media file matching ";

airsonic-main/src/main/java/org/airsonic/player/service/search/IndexType.java

@@ -72,7 +72,6 @@ public enum IndexType {
             FieldNames.ARTIST),
         boosts(
             entry(FieldNames.ARTIST, 2F))),
-
     ;
 
     @SafeVarargs

airsonic-main/src/main/java/org/airsonic/player/service/upnp/ArtistUpnpProcessor.java

@@ -64,7 +64,7 @@ public class ArtistUpnpProcessor extends UpnpContentProcessor <Artist, Album> {
         List<MusicFolder> allFolders = getDispatcher().getSettingsService().getAllMusicFolders();
         List<Artist> allArtists = getArtistDao().getAlphabetialArtists(0, Integer.MAX_VALUE, allFolders);
         // alpha artists doesn't quite work :P
-        allArtists.sort((Artist o1, Artist o2)->o1.getName().replaceAll("\\W", "").compareToIgnoreCase(o2.getName().replaceAll("\\W", "")));
+        allArtists.sort((Artist o1, Artist o2) -> o1.getName().replaceAll("\\W", "").compareToIgnoreCase(o2.getName().replaceAll("\\W", "")));
 
         return allArtists;
     }

airsonic-main/src/main/java/org/airsonic/player/service/upnp/CustomContentDirectory.java

@@ -114,7 +114,7 @@ public abstract class CustomContentDirectory extends AbstractContentDirectorySer
 
     protected String getBaseUrl() {
         String dlnaBaseLANURL = settingsService.getDlnaBaseLANURL();
-        if(StringUtils.isBlank(dlnaBaseLANURL)) {
+        if (StringUtils.isBlank(dlnaBaseLANURL)) {
             throw new RuntimeException("DLNA Base LAN URL is not set correctly");
         }
         return dlnaBaseLANURL;

airsonic-main/src/main/java/org/airsonic/player/service/upnp/DispatchingContentDirectory.java

@@ -152,7 +152,7 @@ public class DispatchingContentDirectory extends CustomContentDirectory {
 
 
     private UpnpContentProcessor findProcessor(String type) {
-        switch(type) {
+        switch (type) {
             case CONTAINER_ID_ROOT:
                 return getRootProcessor();
             case CONTAINER_ID_PLAYLIST_PREFIX:

airsonic-main/src/main/java/org/airsonic/player/service/upnp/GenreUpnpProcessor.java

@@ -58,9 +58,9 @@ public class GenreUpnpProcessor extends UpnpContentProcessor <Genre, MediaFile>
             // sort items
         }
         List<Genre> selectedItems = Util.subList(allItems, firstResult, maxResults);
-        for (int i=0; i < selectedItems.size(); i++) {
+        for (int i = 0; i < selectedItems.size(); i++) {
             Genre item = selectedItems.get(i);
-            didl.addContainer(createContainer(item, (int) (i+firstResult)));
+            didl.addContainer(createContainer(item, (int) (i + firstResult)));
         }
         return createBrowseResult(didl, (int) didl.getCount(), allItems.size());
     }

airsonic-main/src/main/java/org/airsonic/player/service/upnp/MediaFileUpnpProcessor.java

@@ -108,7 +108,7 @@ public class MediaFileUpnpProcessor extends UpnpContentProcessor <MediaFile, Med
 
     public List<MediaFile> getChildren(MediaFile item) {
         List<MediaFile> children = getMediaFileService().getChildrenOf(item, true, true, true);
-        children.sort((MediaFile o1, MediaFile o2)->o1.getPath().replaceAll("\\W", "").compareToIgnoreCase(o2.getPath().replaceAll("\\W", "")));
+        children.sort((MediaFile o1, MediaFile o2) -> o1.getPath().replaceAll("\\W", "").compareToIgnoreCase(o2.getPath().replaceAll("\\W", "")));
         return children;
     }
 

airsonic-main/src/main/java/org/airsonic/player/spring/CustomPropertySourceConfigurer.java

@@ -31,7 +31,7 @@ public class CustomPropertySourceConfigurer implements
     private void addDataSourceProfile(ConfigurableWebApplicationContext ctx) {
         DataSourceConfigType dataSourceConfigType;
         String rawType = ctx.getEnvironment().getProperty(DATASOURCE_CONFIG_TYPE);
-        if(StringUtils.isNotBlank(rawType)) {
+        if (StringUtils.isNotBlank(rawType)) {
             dataSourceConfigType = DataSourceConfigType.valueOf(StringUtils.upperCase(rawType));
         } else {
             dataSourceConfigType = DataSourceConfigType.LEGACY;

airsonic-main/src/main/java/org/airsonic/player/spring/DbmsVersionPrecondition.java

@@ -15,10 +15,10 @@ public class DbmsVersionPrecondition implements CustomPrecondition {
         try {
             int dbMajor = database.getDatabaseMajorVersion();
             int dbMinor = database.getDatabaseMinorVersion();
-            if(major != null && !major.equals(dbMajor)) {
+            if (major != null && !major.equals(dbMajor)) {
                 throw new CustomPreconditionFailedException("DBMS Major Version Precondition failed: expected " + major + ", got " + dbMajor);
             }
-            if(minor != null && !minor.equals(dbMinor)) {
+            if (minor != null && !minor.equals(dbMinor)) {
                 throw new CustomPreconditionFailedException("DBMS Minor Version Precondition failed: expected " + minor + ", got " + dbMinor);
             }
         } catch (DatabaseException e) {

airsonic-main/src/main/java/org/airsonic/player/spring/HsqlDatabase.java

@@ -7,7 +7,7 @@ public class HsqlDatabase extends liquibase.database.core.HsqlDatabase {
     @Override
     public boolean supportsSchemas() {
         try {
-            if(getDatabaseMajorVersion() < 2) {
+            if (getDatabaseMajorVersion() < 2) {
                 return false;
             } else {
                 return super.supportsSchemas();

airsonic-main/src/main/java/org/airsonic/player/spring/RegisterPrecompiledJSPInitializer.java

@@ -28,7 +28,7 @@ public class RegisterPrecompiledJSPInitializer implements ServletContextInitiali
 
     @Override
     public void onStartup(ServletContext servletContext) {
-        if(SettingsService.isDevelopmentMode()) {
+        if (SettingsService.isDevelopmentMode()) {
             logger.debug("Not registering precompiled jsps");
         } else {
             logger.debug("Registering precompiled jsps");

airsonic-main/src/main/java/org/airsonic/player/spring/SpringLiquibase.java

@@ -24,7 +24,7 @@ public class SpringLiquibase extends liquibase.integration.spring.SpringLiquibas
         logger.trace("Starting Liquibase Update");
         try {
             super.afterPropertiesSet();
-        } catch(Exception e) {
+        } catch (Exception e) {
             logger.error("===============================================");
             logger.error("An exception occurred during database migration");
             logger.error("A rollback file has been generated at " + rollbackFile);
@@ -66,9 +66,9 @@ public class SpringLiquibase extends liquibase.integration.spring.SpringLiquibas
 
     private void removeCurrentHsqlDb(List<Database> implementedDatabases) {
         Iterator<Database> iterator = implementedDatabases.iterator();
-        while(iterator.hasNext()) {
+        while (iterator.hasNext()) {
             Database db = iterator.next();
-            if(db instanceof liquibase.database.core.HsqlDatabase) {
+            if (db instanceof liquibase.database.core.HsqlDatabase) {
                 iterator.remove();
             }
         }

airsonic-main/src/main/java/org/airsonic/player/spring/webxmldomain/ServletDef.java

@@ -8,10 +8,10 @@ import javax.xml.bind.annotation.XmlRootElement;
 @XmlRootElement
 @XmlAccessorType(XmlAccessType.FIELD)
 public class ServletDef {
-    @XmlElement(name="servlet-name")
+    @XmlElement(name = "servlet-name")
     private String name;
 
-    @XmlElement(name="servlet-class")
+    @XmlElement(name = "servlet-class")
     private String sclass;
 
     public String getName() {

airsonic-main/src/main/java/org/airsonic/player/spring/webxmldomain/ServletMappingDef.java

@@ -8,10 +8,10 @@ import javax.xml.bind.annotation.XmlRootElement;
 @XmlRootElement
 @XmlAccessorType(XmlAccessType.FIELD)
 public class ServletMappingDef {
-    @XmlElement(name="servlet-name")
+    @XmlElement(name = "servlet-name")
     private String name;
 
-    @XmlElement(name="url-pattern")
+    @XmlElement(name = "url-pattern")
     private String urlPattern;
 
     public String getName() {

airsonic-main/src/main/java/org/airsonic/player/spring/webxmldomain/WebApp.java

@@ -7,13 +7,13 @@ import javax.xml.bind.annotation.XmlRootElement;
 
 import java.util.List;
 
-@XmlRootElement(name="web-app")
+@XmlRootElement(name = "web-app")
 @XmlAccessorType(XmlAccessType.FIELD)
 public class WebApp {
-    @XmlElement(name="servlet")
+    @XmlElement(name = "servlet")
     private List<ServletDef> servletDefs;
 
-    @XmlElement(name="servlet-mapping")
+    @XmlElement(name = "servlet-mapping")
     private List<ServletMappingDef> servletMappingDefs;
 
     public List<ServletDef> getServletDefs() {

checkstyle.xml

@@ -31,11 +31,22 @@
         <module name="EqualsHashCode"/>
         <module name="Indentation"/>
         <module name="InnerAssignment"/>
+        <module name="MethodParamPad"/>
+        <module name="NoWhitespaceBefore">
+            <property name="allowLineBreaks" value="true"/>
+        </module>
         <module name="OneStatementPerLine"/>
         <module name="ParenPadCheck"/>
         <module name="RedundantImport"/>
         <module name="StringLiteralEquality"/>
         <module name="TypecastParenPad"/>
         <module name="UnusedImports"/>
+        <module name="WhitespaceAround">
+            <property name="allowEmptyCatches" value="true"/>
+            <property name="allowEmptyConstructors" value="true"/>
+            <property name="allowEmptyLambdas" value="true"/>
+            <property name="allowEmptyMethods" value="true"/>
+            <property name="allowEmptyTypes" value="true"/>
+        </module>
     </module>
 </module>