Minor: Rename StringUtils#isEmpty to #isBlank

- Better fits the naming used by other tools and also the JDK (String#isBlank as of JDK 11)

src/main/java/fr/xephi/authme/command/CommandDescription.java

@@ -226,8 +226,8 @@ public class CommandDescription {
          */
         public CommandDescription build() {
             checkArgument(!Utils.isCollectionEmpty(labels), "Labels may not be empty");
-            checkArgument(!StringUtils.isEmpty(description), "Description may not be empty");
-            checkArgument(!StringUtils.isEmpty(detailedDescription), "Detailed description may not be empty");
+            checkArgument(!StringUtils.isBlank(description), "Description may not be empty");
+            checkArgument(!StringUtils.isBlank(detailedDescription), "Detailed description may not be empty");
             checkArgument(executableCommand != null, "Executable command must be set");
             // parents and permissions may be null; arguments may be empty
 

src/main/java/fr/xephi/authme/command/CommandHandler.java

@@ -131,7 +131,7 @@ public class CommandHandler {
     private static List<String> skipEmptyArguments(String[] args) {
         List<String> cleanArguments = new ArrayList<>();
         for (String argument : args) {
-            if (!StringUtils.isEmpty(argument)) {
+            if (!StringUtils.isBlank(argument)) {
                 cleanArguments.add(argument);
             }
         }

src/main/java/fr/xephi/authme/command/executable/authme/debug/PlayerAuthViewer.java

@@ -89,7 +89,7 @@ class PlayerAuthViewer implements DebugSection {
      *         or empty string if the string is null or empty
      */
     private static String safeSubstring(String str, int length) {
-        if (StringUtils.isEmpty(str)) {
+        if (StringUtils.isBlank(str)) {
             return "";
         } else if (str.length() < length) {
             return str.substring(0, str.length() / 2) + "...";

src/main/java/fr/xephi/authme/listener/OnJoinVerifier.java

@@ -160,7 +160,7 @@ public class OnJoinVerifier implements Reloadable {
         if (auth != null && settings.getProperty(RegistrationSettings.PREVENT_OTHER_CASE)) {
             String realName = auth.getRealName(); // might be null or "Player"
 
-            if (StringUtils.isEmpty(realName) || "Player".equals(realName)) {
+            if (StringUtils.isBlank(realName) || "Player".equals(realName)) {
                 dataSource.updateRealName(connectingName.toLowerCase(Locale.ROOT), connectingName);
             } else if (!realName.equals(connectingName)) {
                 throw new FailedVerificationException(MessageKey.INVALID_NAME_CASE, realName, connectingName);

src/main/java/fr/xephi/authme/mail/SendMailSsl.java

@@ -51,11 +51,11 @@ public class SendMailSsl {
      * @throws EmailException if the mail is invalid
      */
     public HtmlEmail initializeMail(String emailAddress) throws EmailException {
-        String senderMail = StringUtils.isEmpty(settings.getProperty(EmailSettings.MAIL_ADDRESS))
+        String senderMail = StringUtils.isBlank(settings.getProperty(EmailSettings.MAIL_ADDRESS))
             ? settings.getProperty(EmailSettings.MAIL_ACCOUNT)
             : settings.getProperty(EmailSettings.MAIL_ADDRESS);
 
-        String senderName = StringUtils.isEmpty(settings.getProperty(EmailSettings.MAIL_SENDER_NAME))
+        String senderName = StringUtils.isBlank(settings.getProperty(EmailSettings.MAIL_SENDER_NAME))
             ? senderMail
             : settings.getProperty(EmailSettings.MAIL_SENDER_NAME);
         String mailPassword = settings.getProperty(EmailSettings.MAIL_PASSWORD);

src/main/java/fr/xephi/authme/permission/PermissionsManager.java

@@ -324,7 +324,7 @@ public class PermissionsManager implements Reloadable {
      *         False is also returned if this feature isn't supported for the current permissions system.
      */
     public boolean addGroup(OfflinePlayer player, UserGroup groupName) {
-        if (!isEnabled() || StringUtils.isEmpty(groupName.getGroupName())) {
+        if (!isEnabled() || StringUtils.isBlank(groupName.getGroupName())) {
             return false;
         }
         return handler.addToGroup(player, groupName);

src/main/java/fr/xephi/authme/service/JoinMessageService.java

@@ -38,7 +38,7 @@ public class JoinMessageService {
      */
     public void sendMessage(String playerName) {
         String joinMessage = joinMessages.remove(playerName);
-        if (!StringUtils.isEmpty(joinMessage)) {
+        if (!StringUtils.isBlank(joinMessage)) {
             bukkitService.broadcastMessage(joinMessage);
         }
     }

src/main/java/fr/xephi/authme/settings/SettingsMigrationService.java

@@ -114,7 +114,7 @@ public class SettingsMigrationService extends PlainMigrationService {
     // Old other accounts
     // --------
     public boolean hasOldOtherAccountsCommand() {
-        return !StringUtils.isEmpty(oldOtherAccountsCommand);
+        return !StringUtils.isBlank(oldOtherAccountsCommand);
     }
 
     public String getOldOtherAccountsCommand() {

src/main/java/fr/xephi/authme/settings/SpawnLoader.java

@@ -293,7 +293,7 @@ public class SpawnLoader implements Reloadable {
             String prefix = pathPrefix + ".";
             String worldName = configuration.getString(prefix + "world");
             World world = Bukkit.getWorld(worldName);
-            if (!StringUtils.isEmpty(worldName) && world != null) {
+            if (!StringUtils.isBlank(worldName) && world != null) {
                 return new Location(world, configuration.getDouble(prefix + "x"),
                     configuration.getDouble(prefix + "y"), configuration.getDouble(prefix + "z"),
                     getFloat(configuration, prefix + "yaw"), getFloat(configuration, prefix + "pitch"));
@@ -315,7 +315,7 @@ public class SpawnLoader implements Reloadable {
             String prefix = pathPrefix + ".";
             String worldName = configuration.getString(prefix + "World");
             World world = Bukkit.getWorld(worldName);
-            if (!StringUtils.isEmpty(worldName) && world != null) {
+            if (!StringUtils.isBlank(worldName) && world != null) {
                 return new Location(world, configuration.getDouble(prefix + "X"),
                     configuration.getDouble(prefix + "Y"), configuration.getDouble(prefix + "Z"),
                     getFloat(configuration, prefix + "Yaw"), getFloat(configuration, prefix + "Pitch"));

src/main/java/fr/xephi/authme/util/StringUtils.java

@@ -14,12 +14,11 @@ public final class StringUtils {
     }
 
     /**
-     * Get the difference of two strings.
+     * Calculates the difference of two strings.
      *
-     * @param first  First string
-     * @param second Second string
-     *
-     * @return The difference value
+     * @param first  first string
+     * @param second second string
+     * @return the difference value
      */
     public static double getDifference(String first, String second) {
         // Make sure the strings are valid.
@@ -35,12 +34,11 @@ public final class StringUtils {
     }
 
     /**
-     * Return whether the given string contains any of the provided elements.
+     * Returns whether the given string contains any of the provided elements.
      *
-     * @param str    The string to analyze
-     * @param pieces The items to check the string for
-     *
-     * @return True if the string contains at least one of the items
+     * @param str    the string to analyze
+     * @param pieces the items to check the string for
+     * @return true if the string contains at least one of the items
      */
     public static boolean containsAny(String str, Iterable<String> pieces) {
         if (str == null) {
@@ -58,21 +56,19 @@ public final class StringUtils {
      * Null-safe method for checking whether a string is empty. Note that the string
      * is trimmed, so this method also considers a string with whitespace as empty.
      *
-     * @param str The string to verify
-     *
-     * @return True if the string is empty, false otherwise
+     * @param str the string to verify
+     * @return true if the string is empty, false otherwise
      */
-    public static boolean isEmpty(String str) {
+    public static boolean isBlank(String str) {
         return str == null || str.trim().isEmpty();
     }
 
     /**
-     * Check that the given needle is in the middle of the haystack, i.e. that the haystack
+     * Checks that the given needle is in the middle of the haystack, i.e. that the haystack
      * contains the needle and that it is not at the very start or end.
      *
      * @param needle the needle to search for
      * @param haystack the haystack to search in
-     *
      * @return true if the needle is in the middle of the word, false otherwise
      */
     // Note ljacqu 20170314: `needle` is restricted to char type intentionally because something like

src/main/java/fr/xephi/authme/util/Utils.java

@@ -105,6 +105,6 @@ public final class Utils {
      * @return true if the email is empty
      */
     public static boolean isEmailEmpty(String email) {
-        return StringUtils.isEmpty(email) || "your@email.com".equalsIgnoreCase(email);
+        return StringUtils.isBlank(email) || "your@email.com".equalsIgnoreCase(email);
     }
 }

src/test/java/fr/xephi/authme/command/CommandInitializerTest.java

@@ -138,11 +138,11 @@ public class CommandInitializerTest {
                 String forCommandText = " for command with labels '" + command.getLabels() + "'";
 
                 assertThat("has description" + forCommandText,
-                    StringUtils.isEmpty(command.getDescription()), equalTo(false));
+                    StringUtils.isBlank(command.getDescription()), equalTo(false));
                 assertThat("short description doesn't end in '.'" + forCommandText,
                     command.getDescription().endsWith("."), equalTo(false));
                 assertThat("has detailed description" + forCommandText,
-                    StringUtils.isEmpty(command.getDetailedDescription()), equalTo(false));
+                    StringUtils.isBlank(command.getDetailedDescription()), equalTo(false));
                 assertThat("detailed description ends in '.'" + forCommandText,
                     command.getDetailedDescription().endsWith("."), equalTo(true));
             }

src/test/java/fr/xephi/authme/command/executable/authme/ConverterCommandTest.java

@@ -93,7 +93,7 @@ public class ConverterCommandTest {
         // when / then
         for (Map.Entry<String, Class<? extends Converter>> entry : ConverterCommand.CONVERTERS.entrySet()) {
             assertThat("Name is not null or empty",
-                StringUtils.isEmpty(entry.getKey()), equalTo(false));
+                StringUtils.isBlank(entry.getKey()), equalTo(false));
 
             assertThat("Converter class is unique for each entry",
                 classes.add(entry.getValue()), equalTo(true));

src/test/java/fr/xephi/authme/command/help/HelpMessageAndHelpSectionConsistencyTest.java

@@ -23,14 +23,14 @@ public class HelpMessageAndHelpSectionConsistencyTest {
         // when / then
         for (HelpMessage message : HelpMessage.values()) {
             assertThat("Key for message '" + message + "' is empty",
-                StringUtils.isEmpty(message.getKey()), equalTo(false));
+                StringUtils.isBlank(message.getKey()), equalTo(false));
             if (!keys.add(message.getKey())) {
                 fail("Key for message '" + message + "' is already used elsewhere");
             }
         }
         for (HelpSection section : HelpSection.values()) {
             assertThat("Key for section '" + section + "' is empty",
-                StringUtils.isEmpty(section.getKey()), equalTo(false));
+                StringUtils.isBlank(section.getKey()), equalTo(false));
             if (!keys.add(section.getKey())) {
                 fail("Key for section '" + section + "' is already used elsewhere");
             }

src/test/java/fr/xephi/authme/message/MessageKeyTest.java

@@ -27,7 +27,7 @@ public class MessageKeyTest {
             String key = messageKey.getKey();
             if (!keys.add(key)) {
                 fail("Found key '" + messageKey.getKey() + "' twice!");
-            } else if (StringUtils.isEmpty(key)) {
+            } else if (StringUtils.isBlank(key)) {
                 fail("Key for message key '" + messageKey + "' is empty");
             }
         }

src/test/java/fr/xephi/authme/message/MessagesFileConsistencyTest.java

@@ -40,7 +40,7 @@ public class MessagesFileConsistencyTest {
         final String key = messageKey.getKey();
         final String message = reader.getString(key);
 
-        if (StringUtils.isEmpty(message)) {
+        if (StringUtils.isBlank(message)) {
             errors.add("Messages file should have message for key '" + key + "'");
             return;
         }

src/test/java/fr/xephi/authme/message/YamlTextFileCheckerTest.java

@@ -81,7 +81,7 @@ public class YamlTextFileCheckerTest {
     private void checkFile(File file, String mandatoryKey, List<String> errors) {
         try {
             PropertyReader reader = new YamlFileReader(file);
-            if (StringUtils.isEmpty(reader.getString(mandatoryKey))) {
+            if (StringUtils.isBlank(reader.getString(mandatoryKey))) {
                 errors.add("Message for '" + mandatoryKey + "' is empty");
             }
         } catch (Exception e) {

src/test/java/fr/xephi/authme/security/HashAlgorithmIntegrationTest.java

@@ -74,9 +74,9 @@ public class HashAlgorithmIntegrationTest {
                 }
                 HashedPassword hashedPassword = method.computeHash("pwd", "name");
                 assertThat("Salt should not be null if method.hasSeparateSalt(), and vice versa. Method: '"
-                    + method + "'", StringUtils.isEmpty(hashedPassword.getSalt()), equalTo(!method.hasSeparateSalt()));
+                    + method + "'", StringUtils.isBlank(hashedPassword.getSalt()), equalTo(!method.hasSeparateSalt()));
                 assertThat("Hash should not be empty for method '" + method + "'",
-                    StringUtils.isEmpty(hashedPassword.getHash()), equalTo(false));
+                    StringUtils.isBlank(hashedPassword.getHash()), equalTo(false));
             }
         }
     }

src/test/java/fr/xephi/authme/util/StringUtilsTest.java

@@ -49,15 +49,15 @@ public class StringUtilsTest {
     }
 
     @Test
-    public void shouldCheckIsEmptyUtil() {
+    public void shouldCheckIfIsBlankString() {
         // Should be true for null/empty/whitespace
-        assertTrue(StringUtils.isEmpty(null));
-        assertTrue(StringUtils.isEmpty(""));
-        assertTrue(StringUtils.isEmpty(" \t"));
+        assertTrue(StringUtils.isBlank(null));
+        assertTrue(StringUtils.isBlank(""));
+        assertTrue(StringUtils.isBlank(" \t"));
 
         // Should be false if string has content
-        assertFalse(StringUtils.isEmpty("P"));
-        assertFalse(StringUtils.isEmpty(" test"));
+        assertFalse(StringUtils.isBlank("P"));
+        assertFalse(StringUtils.isBlank(" test"));
     }
 
     @Test

src/test/java/tools/messages/VerifyMessagesTask.java

@@ -44,7 +44,7 @@ public final class VerifyMessagesTask implements ToolTask {
         boolean addMissingKeys = "y".equalsIgnoreCase(scanner.nextLine());
 
         List<File> messageFiles;
-        if (StringUtils.isEmpty(inputFile)) {
+        if (StringUtils.isBlank(inputFile)) {
             messageFiles = getMessagesFiles();
         } else {
             File customFile = new File(MAIN_RESOURCES_ROOT, MessagePathHelper.createMessageFilePath(inputFile));