Create Wrapper as singleton; fix UtilsTest

src/main/java/fr/xephi/authme/AntiBot.java

@@ -17,7 +17,7 @@ public class AntiBot {
 
     private static final AuthMe plugin = AuthMe.getInstance();
     private static final Messages messages = plugin.getMessages();
-    private static Wrapper wrapper = new Wrapper(plugin);
+    private static Wrapper wrapper = Wrapper.getInstance();
     private static final List<String> antibotPlayers = new ArrayList<>();
     private static AntiBotStatus antiBotStatus = AntiBotStatus.DISABLED;
 

src/main/java/fr/xephi/authme/ConsoleLogger.java

@@ -17,7 +17,7 @@ import java.util.Date;
  */
 public final class ConsoleLogger {
 
-    private static Wrapper wrapper = new Wrapper(AuthMe.getInstance());
+    private static Wrapper wrapper = Wrapper.getInstance();
     private static final DateFormat df = new SimpleDateFormat("[MM-dd HH:mm:ss]");
 
     private ConsoleLogger() {

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

@@ -17,7 +17,6 @@ public class GeoLiteAPI {
         "available at http://www.maxmind.com";
     private static final String GEOIP_URL = "http://geolite.maxmind.com/download/geoip/database/GeoLiteCountry" +
         "/GeoIP.dat.gz";
-    private static final Wrapper wrapper = new Wrapper(AuthMe.getInstance());
     private static final AuthMe plugin = AuthMe.getInstance();
     private static LookupService lookupService;
 

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

@@ -26,7 +26,7 @@ import java.util.Collections;
  */
 public final class Utils {
 
-    private static final AuthMe plugin;
+    private static AuthMe plugin;
     private static Wrapper wrapper;
 
     private static boolean getOnlinePlayersIsCollection = false;
@@ -34,7 +34,7 @@ public final class Utils {
 
     static {
         plugin = AuthMe.getInstance();
-        wrapper = new Wrapper(plugin);
+        wrapper = Wrapper.getInstance();
         initializeOnlinePlayersIsCollectionField();
     }
 
@@ -116,9 +116,10 @@ public final class Utils {
 
         // Get the permissions manager, and make sure it's valid
         PermissionsManager permsMan = plugin.getPermissionsManager();
-        if (permsMan == null)
-            ConsoleLogger.showError("Failed to access permissions manager instance, shutting down.");
-        assert permsMan != null;
+        if (permsMan == null) {
+            ConsoleLogger.showError("Failed to access permissions manager instance, aborting.");
+            return false;
+        }
 
         // Remove old groups
         permsMan.removeGroups(player, Arrays.asList(Settings.unRegisteredGroup,

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

@@ -13,22 +13,31 @@ import java.util.logging.Logger;
  */
 public class Wrapper {
 
-    private AuthMe authMe;
+    private static Wrapper singleton;
 
-    public Wrapper(AuthMe authMe) {
-        this.authMe = authMe;
+    /**
+     * Package-private constructor for testing purposes to inject a mock instance.
+     */
+    Wrapper() {
+    }
+
+    public static Wrapper getInstance() {
+        if (singleton == null) {
+            singleton = new Wrapper();
+        }
+        return singleton;
     }
 
     public AuthMe getAuthMe() {
-        return authMe;
+        return AuthMe.getInstance();
     }
 
     public Server getServer() {
-        return authMe.getServer();
+        return getAuthMe().getServer();
     }
 
     public Logger getLogger() {
-        return authMe.getLogger();
+        return getAuthMe().getLogger();
     }
 
     public BukkitScheduler getScheduler() {