Added Island#isOwned(), Island#isUnowned() and improved javadoc on Island#getOwner()

src/main/java/world/bentobox/bentobox/api/commands/admin/AdminRegisterCommand.java

@@ -62,7 +62,7 @@ public class AdminRegisterCommand extends ConfirmableCommand {
         }
         // Check if island is owned
         Optional<Island> island = getIslands().getIslandAt(user.getLocation());
-        if (island.map(i -> i.getOwner() != null).orElse(false)) {
+        if (island.map(Island::isOwned).orElse(false)) {
             user.sendMessage("commands.admin.register.already-owned");
             return false;
         }

src/main/java/world/bentobox/bentobox/api/commands/admin/AdminSetspawnCommand.java

@@ -56,7 +56,7 @@ public class AdminSetspawnCommand extends ConfirmableCommand {
 
     private void setSpawn(User user, Island i) {
         if (!i.getMembers().isEmpty()) {
-            if (i.getOwner() != null) {
+            if (i.isOwned()) {
                 // Fire event
                 IslandBaseEvent event = IslandEvent.builder()
                         .island(i)

src/main/java/world/bentobox/bentobox/api/commands/admin/purge/AdminPurgeCommand.java

@@ -120,7 +120,7 @@ public class AdminPurgeCommand extends CompositeCommand implements Listener {
         return getPlugin().getIslands().getIslands().stream()
                 .filter(i -> !i.getPurgeProtected())
                 .filter(i -> i.getWorld().equals(this.getWorld()))
-                .filter(i -> i.getOwner() != null)
+                .filter(Island::isOwned)
                 .filter(i -> i.getMembers().size() == 1)
                 .filter(i -> (System.currentTimeMillis() - Bukkit.getOfflinePlayer(i.getOwner()).getLastPlayed()) > days * 1000 * 24 * 3600)
                 .map(Island::getUniqueId)

src/main/java/world/bentobox/bentobox/api/commands/admin/purge/AdminPurgeUnownedCommand.java

@@ -51,7 +51,7 @@ public class AdminPurgeUnownedCommand extends ConfirmableCommand {
         return getPlugin().getIslands().getIslands().stream()
                 .filter(i -> !i.getPurgeProtected())
                 .filter(i -> i.getWorld().equals(this.getWorld()))
-                .filter(i -> i.getOwner() == null)
+                .filter(Island::isUnowned)
                 .map(Island::getUniqueId)
                 .collect(Collectors.toSet());
 

src/main/java/world/bentobox/bentobox/api/commands/island/IslandNearCommand.java

@@ -80,7 +80,7 @@ public class IslandNearCommand extends CompositeCommand {
         if (island.getName() != null && !island.getName().isEmpty()) {
             return island.getName();
         }
-        if (island.getOwner() == null) {
+        if (island.isUnowned()) {
             return user.getTranslation("commands.admin.info.unowned");
         }
         return getPlayers().getName(island.getOwner());

src/main/java/world/bentobox/bentobox/database/objects/Island.java

@@ -441,13 +441,38 @@ public class Island implements DataObject {
     }
 
     /**
-     * @return the owner
+     * Returns the owner of this island.
+     * @return the owner, may be null.
+     * @see #isOwned()
+     * @see #isUnowned()
      */
     @Nullable
     public UUID getOwner(){
         return owner;
     }
 
+    /**
+     * Returns whether this island is owned or not.
+     * @return {@code true} if this island has an owner, {@code false} otherwise.
+     * @since 1.9.1
+     * @see #getOwner()
+     * @see #isUnowned()
+     */
+    public boolean isOwned() {
+        return owner != null;
+    }
+
+    /**
+     * Returns whether this island does not have an owner.
+     * @return {@code true} if this island does not have an owner, {@code false} otherwise.
+     * @since 1.9.1
+     * @see #getOwner()
+     * @see #isOwned()
+     */
+    public boolean isUnowned() {
+        return owner == null;
+    }
+
     /**
      * @return the protectionRange
      */

src/main/java/world/bentobox/bentobox/listeners/flags/worldsettings/EnterExitListener.java

@@ -97,7 +97,7 @@ public class EnterExitListener extends FlagListener {
         }
 
         // Send message if island is owned by someone
-        if (island.getOwner() != null) {
+        if (island.isOwned()) {
             // Leave messages are always specific to this world
             user.notify(island.getWorld(), "protection.flags.ENTER_EXIT_MESSAGES.now-leaving", TextVariables.NAME, (island.getName() != null) ? island.getName() :
                 user.getTranslation(island.getWorld(), "protection.flags.ENTER_EXIT_MESSAGES.island", TextVariables.NAME, getPlugin().getPlayers().getName(island.getOwner())));
@@ -121,7 +121,7 @@ public class EnterExitListener extends FlagListener {
         }
 
         // Send message if island is owned by someone
-        if (island.getOwner() != null) {
+        if (island.isOwned()) {
             // Leave messages are always specific to this world
             user.notify(island.getWorld(), "protection.flags.ENTER_EXIT_MESSAGES.now-entering", TextVariables.NAME, (island.getName() != null) ? island.getName() :
                 user.getTranslation(island.getWorld(), "protection.flags.ENTER_EXIT_MESSAGES.island", TextVariables.NAME, getPlugin().getPlayers().getName(island.getOwner())));

src/main/java/world/bentobox/bentobox/managers/IslandsManager.java

@@ -842,7 +842,7 @@ public class IslandsManager {
                     // Add to quarantine cache
                     island.setDoNotLoad(true);
                     quarantineCache.computeIfAbsent(island.getOwner(), k -> new ArrayList<>()).add(island);
-                    if (island.getOwner() == null) {
+                    if (island.isUnowned()) {
                         unowned++;
                     } else {
                         owned++;

src/main/java/world/bentobox/bentobox/managers/island/IslandCache.java

@@ -67,7 +67,7 @@ public class IslandCache {
             // Make world
             islandsByUUID.putIfAbsent(island.getWorld(), new HashMap<>());
             // Only add islands to this map if they are owned
-            if (island.getOwner() != null) {
+            if (island.isOwned()) {
                 islandsByUUID.get(island.getWorld()).put(island.getOwner(), island);
                 island.getMemberSet().forEach(member -> islandsByUUID.get(island.getWorld()).put(member, island));
             }
@@ -235,7 +235,7 @@ public class IslandCache {
         islandsByUUID.putIfAbsent(world, new HashMap<>());
         Island island = islandsByUUID.get(world).get(uuid);
         if (island != null) {
-            if (island.getOwner() != null && island.getOwner().equals(uuid)) {
+            if (uuid.equals(island.getOwner())) {
                 // Clear ownership and members
                 island.getMembers().clear();
                 island.setOwner(null);