Finalize fields where possible (#1021)

src/main/java/me/ryanhamshire/GriefPrevention/AutoExtendClaimTask.java

@@ -11,9 +11,9 @@ import java.util.ArrayList;
 //automatically extends a claim downward based on block types detected
 class AutoExtendClaimTask implements Runnable
 {
-    private Claim claim;
-    private ArrayList<ChunkSnapshot> chunks;
-    private Environment worldType;
+    private final Claim claim;
+    private final ArrayList<ChunkSnapshot> chunks;
+    private final Environment worldType;
 
     public AutoExtendClaimTask(Claim claim, ArrayList<ChunkSnapshot> chunks, Environment worldType)
     {
@@ -113,8 +113,8 @@ class AutoExtendClaimTask implements Runnable
     //runs in the main execution thread, where it can safely change claims and save those changes
     private class ExecuteExtendClaimTask implements Runnable
     {
-        private Claim claim;
-        private int newY;
+        private final Claim claim;
+        private final int newY;
 
         public ExecuteExtendClaimTask(Claim claim, int newY)
         {

src/main/java/me/ryanhamshire/GriefPrevention/BlockEventHandler.java

@@ -76,9 +76,9 @@ import java.util.UUID;
 public class BlockEventHandler implements Listener
 {
     //convenience reference to singleton datastore
-    private DataStore dataStore;
+    private final DataStore dataStore;
 
-    private ArrayList<Material> trashBlocks;
+    private final ArrayList<Material> trashBlocks;
 
     //constructor
     public BlockEventHandler(DataStore dataStore)

src/main/java/me/ryanhamshire/GriefPrevention/BroadcastMessageTask.java

@@ -24,7 +24,7 @@ import org.bukkit.Bukkit;
 //used to send delayed messages, for example a quit message after the player has been gone a while 
 class BroadcastMessageTask implements Runnable
 {
-    private String message;
+    private final String message;
 
     public BroadcastMessageTask(String message)
     {

src/main/java/me/ryanhamshire/GriefPrevention/CheckForPortalTrapTask.java

@@ -30,10 +30,10 @@ class CheckForPortalTrapTask extends BukkitRunnable
 {
     GriefPrevention instance;
     //player who recently teleported via nether portal
-    private Player player;
+    private final Player player;
 
     //where to send the player back to if he hasn't left the portal frame
-    private Location returnLocation;
+    private final Location returnLocation;
 
     public CheckForPortalTrapTask(Player player, GriefPrevention plugin, Location locationToReturn)
     {

src/main/java/me/ryanhamshire/GriefPrevention/CustomLogger.java

@@ -37,7 +37,7 @@ class CustomLogger
     private final int secondsBetweenWrites = 300;
 
     //stringbuilder is not thread safe, stringbuffer is
-    private StringBuffer queuedEntries = new StringBuffer();
+    private final StringBuffer queuedEntries = new StringBuffer();
 
     CustomLogger()
     {

src/main/java/me/ryanhamshire/GriefPrevention/DataStore.java

@@ -512,7 +512,7 @@ public abstract class DataStore
     }
 
     //turns a location into a string, useful in data storage
-    private String locationStringDelimiter = ";";
+    private final String locationStringDelimiter = ";";
 
     String locationToString(Location location)
     {
@@ -1198,7 +1198,7 @@ public abstract class DataStore
     }
 
     //timestamp for each siege cooldown to end
-    private HashMap<String, Long> siegeCooldownRemaining = new HashMap<>();
+    private final HashMap<String, Long> siegeCooldownRemaining = new HashMap<>();
 
     //whether or not a sieger can siege a particular victim or claim, considering only cooldowns
     synchronized public boolean onCooldown(Player attacker, Player defender, Claim defenderClaim)
@@ -1838,8 +1838,8 @@ public abstract class DataStore
 
     private class SavePlayerDataThread extends Thread
     {
-        private UUID playerID;
-        private PlayerData playerData;
+        private final UUID playerID;
+        private final PlayerData playerData;
 
         SavePlayerDataThread(UUID playerID, PlayerData playerData)
         {

src/main/java/me/ryanhamshire/GriefPrevention/DatabaseDataStore.java

@@ -45,9 +45,9 @@ public class DatabaseDataStore extends DataStore
 {
     private Connection databaseConnection = null;
 
-    private String databaseUrl;
-    private String userName;
-    private String password;
+    private final String databaseUrl;
+    private final String userName;
+    private final String password;
 
     private String updateNameSQL;
     private String insertClaimSQL;

src/main/java/me/ryanhamshire/GriefPrevention/DeliverClaimBlocksTask.java

@@ -28,9 +28,9 @@ import java.util.Collection;
 //runs every 5 minutes in the main thread, grants blocks per hour / 12 to each online player who appears to be actively playing
 class DeliverClaimBlocksTask implements Runnable
 {
-    private Player player;
-    private GriefPrevention instance;
-    private int idleThresholdSquared;
+    private final Player player;
+    private final GriefPrevention instance;
+    private final int idleThresholdSquared;
 
     public DeliverClaimBlocksTask(Player player, GriefPrevention instance)
     {

src/main/java/me/ryanhamshire/GriefPrevention/EntityCleanupTask.java

@@ -35,7 +35,7 @@ import java.util.List;
 class EntityCleanupTask implements Runnable
 {
     //where to start cleaning in the list of entities
-    private double percentageStart;
+    private final double percentageStart;
 
     public EntityCleanupTask(double percentageStart)
     {

src/main/java/me/ryanhamshire/GriefPrevention/EntityEventHandler.java

@@ -106,8 +106,8 @@ import java.util.UUID;
 public class EntityEventHandler implements Listener
 {
     //convenience reference for the singleton datastore
-    private DataStore dataStore;
-    GriefPrevention instance;
+    private final DataStore dataStore;
+    private final GriefPrevention instance;
     private final NamespacedKey luredByPlayer;
 
     public EntityEventHandler(DataStore dataStore, GriefPrevention plugin)

src/main/java/me/ryanhamshire/GriefPrevention/EquipShovelProcessingTask.java

@@ -27,7 +27,7 @@ import org.bukkit.inventory.EquipmentSlot;
 class EquipShovelProcessingTask implements Runnable
 {
     //player data
-    private Player player;
+    private final Player player;
 
     public EquipShovelProcessingTask(Player player)
     {

src/main/java/me/ryanhamshire/GriefPrevention/GriefPrevention.java

@@ -3137,8 +3137,8 @@ public class GriefPrevention extends JavaPlugin
     //thread to build the above cache
     private class CacheOfflinePlayerNamesThread extends Thread
     {
-        private OfflinePlayer[] offlinePlayers;
-        private ConcurrentHashMap<String, UUID> playerNameToIDMap;
+        private final OfflinePlayer[] offlinePlayers;
+        private final ConcurrentHashMap<String, UUID> playerNameToIDMap;
 
         CacheOfflinePlayerNamesThread(OfflinePlayer[] offlinePlayers, ConcurrentHashMap<String, UUID> playerNameToIDMap)
         {

src/main/java/me/ryanhamshire/GriefPrevention/IgnoreLoaderThread.java

@@ -11,8 +11,8 @@ import java.util.concurrent.ConcurrentHashMap;
 //loads ignore data from file into a hash map
 class IgnoreLoaderThread extends Thread
 {
-    private UUID playerToLoad;
-    private ConcurrentHashMap<UUID, Boolean> destinationMap;
+    private final UUID playerToLoad;
+    private final ConcurrentHashMap<UUID, Boolean> destinationMap;
 
     IgnoreLoaderThread(UUID playerToLoad, ConcurrentHashMap<UUID, Boolean> destinationMap)
     {

src/main/java/me/ryanhamshire/GriefPrevention/PlayerEventHandler.java

@@ -107,23 +107,23 @@ import java.util.regex.Pattern;
 
 class PlayerEventHandler implements Listener
 {
-    private DataStore dataStore;
-    private GriefPrevention instance;
+    private final DataStore dataStore;
+    private final GriefPrevention instance;
 
     //list of temporarily banned ip's
-    private ArrayList<IpBanInfo> tempBannedIps = new ArrayList<>();
+    private final ArrayList<IpBanInfo> tempBannedIps = new ArrayList<>();
 
     //number of milliseconds in a day
     private final long MILLISECONDS_IN_DAY = 1000 * 60 * 60 * 24;
 
     //timestamps of login and logout notifications in the last minute
-    private ArrayList<Long> recentLoginLogoutNotifications = new ArrayList<>();
+    private final ArrayList<Long> recentLoginLogoutNotifications = new ArrayList<>();
 
     //regex pattern for the "how do i claim land?" scanner
     private Pattern howToClaimPattern = null;
 
     //matcher for banned words
-    private WordFinder bannedWordFinder;
+    private final WordFinder bannedWordFinder;
 
     //spam tracker
     SpamDetector spamDetector = new SpamDetector();
@@ -537,7 +537,7 @@ class PlayerEventHandler implements Listener
         }
     }
 
-    private ConcurrentHashMap<String, CommandCategory> commandCategoryMap = new ConcurrentHashMap<>();
+    private final ConcurrentHashMap<String, CommandCategory> commandCategoryMap = new ConcurrentHashMap<>();
 
     private CommandCategory getCommandCategory(String commandName)
     {
@@ -618,7 +618,7 @@ class PlayerEventHandler implements Listener
         GriefPrevention.AddLogEntry(entryBuilder.toString(), CustomLogEntryTypes.SocialActivity, true);
     }
 
-    private ConcurrentHashMap<UUID, Date> lastLoginThisServerSessionMap = new ConcurrentHashMap<>();
+    private final ConcurrentHashMap<UUID, Date> lastLoginThisServerSessionMap = new ConcurrentHashMap<>();
 
     //when a player attempts to join the server...
     @EventHandler(priority = EventPriority.HIGHEST)
@@ -875,7 +875,7 @@ class PlayerEventHandler implements Listener
     }
 
     //when a player dies...
-    private HashMap<UUID, Long> deathTimestamps = new HashMap<>();
+    private final HashMap<UUID, Long> deathTimestamps = new HashMap<>();
 
     @EventHandler(priority = EventPriority.HIGHEST)
     void onPlayerDeath(PlayerDeathEvent event)
@@ -908,7 +908,7 @@ class PlayerEventHandler implements Listener
     }
 
     //when a player quits...
-    private HashMap<UUID, Integer> heldLogoutMessages = new HashMap<>();
+    private final HashMap<UUID, Integer> heldLogoutMessages = new HashMap<>();
 
     @EventHandler(priority = EventPriority.HIGHEST)
     void onPlayerQuit(PlayerQuitEvent event)
@@ -1449,8 +1449,8 @@ class PlayerEventHandler implements Listener
     }
 
     //block use of buckets within other players' claims
-    private HashSet<Material> commonAdjacentBlocks_water = new HashSet<>(Arrays.asList(Material.WATER, Material.FARMLAND, Material.DIRT, Material.STONE));
-    private HashSet<Material> commonAdjacentBlocks_lava = new HashSet<>(Arrays.asList(Material.LAVA, Material.DIRT, Material.STONE));
+    private final HashSet<Material> commonAdjacentBlocks_water = new HashSet<>(Arrays.asList(Material.WATER, Material.FARMLAND, Material.DIRT, Material.STONE));
+    private final HashSet<Material> commonAdjacentBlocks_lava = new HashSet<>(Arrays.asList(Material.LAVA, Material.DIRT, Material.STONE));
 
     @EventHandler(ignoreCancelled = true, priority = EventPriority.LOWEST)
     public void onPlayerBucketEmpty(PlayerBucketEmptyEvent bucketEvent)
@@ -2623,7 +2623,7 @@ class PlayerEventHandler implements Listener
     }
 
     //determines whether a block type is an inventory holder.  uses a caching strategy to save cpu time
-    private ConcurrentHashMap<Material, Boolean> inventoryHolderCache = new ConcurrentHashMap<>();
+    private final ConcurrentHashMap<Material, Boolean> inventoryHolderCache = new ConcurrentHashMap<>();
 
     private boolean isInventoryHolder(Block clickedBlock)
     {

src/main/java/me/ryanhamshire/GriefPrevention/PlayerKickBanTask.java

@@ -28,16 +28,16 @@ import org.bukkit.entity.Player;
 class PlayerKickBanTask implements Runnable
 {
     //player to kick or ban
-    private Player player;
+    private final Player player;
 
     //message to send player.
-    private String reason;
+    private final String reason;
 
     //source of ban
-    private String source;
+    private final String source;
 
     //whether to ban
-    private boolean ban;
+    private final boolean ban;
 
     public PlayerKickBanTask(Player player, String reason, String source, boolean ban)
     {

src/main/java/me/ryanhamshire/GriefPrevention/PlayerRescueTask.java

@@ -27,13 +27,13 @@ import org.bukkit.entity.Player;
 class PlayerRescueTask implements Runnable
 {
     //original location where /trapped was used
-    private Location location;
+    private final Location location;
 
     //rescue destination, may be decided at instantiation or at execution
     private Location destination;
 
     //player data
-    private Player player;
+    private final Player player;
 
     public PlayerRescueTask(Player player, Location location, Location destination)
     {

src/main/java/me/ryanhamshire/GriefPrevention/PvPImmunityValidationTask.java

@@ -24,7 +24,7 @@ import org.bukkit.entity.Player;
 //used to send delayed messages, for example help text triggered by a player's chat
 class PvPImmunityValidationTask implements Runnable
 {
-    private Player player;
+    private final Player player;
 
     public PvPImmunityValidationTask(Player player)
     {

src/main/java/me/ryanhamshire/GriefPrevention/RestoreNatureExecutionTask.java

@@ -36,15 +36,15 @@ class RestoreNatureExecutionTask implements Runnable
 {
     //results from processing thread
     //will be applied to the world
-    private BlockSnapshot[][][] snapshots;
+    private final BlockSnapshot[][][] snapshots;
 
     //boundaries for changes
-    private int miny;
-    private Location lesserCorner;
-    private Location greaterCorner;
+    private final int miny;
+    private final Location lesserCorner;
+    private final Location greaterCorner;
 
     //player who should be notified about the result (will see a visualization when the restoration is complete)
-    private Player player;
+    private final Player player;
 
     public RestoreNatureExecutionTask(BlockSnapshot[][][] snapshots, int miny, Location lesserCorner, Location greaterCorner, Player player)
     {

src/main/java/me/ryanhamshire/GriefPrevention/RestoreNatureProcessingTask.java

@@ -36,23 +36,23 @@ class RestoreNatureProcessingTask implements Runnable
 {
     //world information captured from the main thread
     //will be updated and sent back to main thread to be applied to the world
-    private BlockSnapshot[][][] snapshots;
+    private final BlockSnapshot[][][] snapshots;
 
     //other information collected from the main thread.
     //not to be updated, only to be passed back to main thread to provide some context about the operation
     private int miny;
-    private Environment environment;
-    private Location lesserBoundaryCorner;
-    private Location greaterBoundaryCorner;
-    private Player player;            //absolutely must not be accessed.  not thread safe.
-    private Biome biome;
-    private boolean creativeMode;
-    private int seaLevel;
-    private boolean aggressiveMode;
+    private final Environment environment;
+    private final Location lesserBoundaryCorner;
+    private final Location greaterBoundaryCorner;
+    private final Player player;            //absolutely must not be accessed.  not thread safe.
+    private final Biome biome;
+    private final boolean creativeMode;
+    private final int seaLevel;
+    private final boolean aggressiveMode;
 
     //two lists of materials
-    private ArrayList<Material> notAllowedToHang;    //natural blocks which don't naturally hang in their air
-    private ArrayList<Material> playerBlocks;        //a "complete" list of player-placed blocks.  MUST BE MAINTAINED as patches introduce more
+    private final ArrayList<Material> notAllowedToHang;    //natural blocks which don't naturally hang in their air
+    private final ArrayList<Material> playerBlocks;        //a "complete" list of player-placed blocks.  MUST BE MAINTAINED as patches introduce more
 
 
     public RestoreNatureProcessingTask(BlockSnapshot[][][] snapshots, int miny, Environment environment, Biome biome, Location lesserBoundaryCorner, Location greaterBoundaryCorner, int seaLevel, boolean aggressiveMode, boolean creativeMode, Player player)

src/main/java/me/ryanhamshire/GriefPrevention/SecureClaimTask.java

@@ -25,7 +25,7 @@ import java.util.Collection;
 //secures a claim after a siege looting window has closed
 class SecureClaimTask implements Runnable
 {
-    private SiegeData siegeData;
+    private final SiegeData siegeData;
 
     public SecureClaimTask(SiegeData siegeData)
     {

src/main/java/me/ryanhamshire/GriefPrevention/SendPlayerMessageTask.java

@@ -25,9 +25,9 @@ import org.bukkit.entity.Player;
 //used to send delayed messages, for example help text triggered by a player's chat
 class SendPlayerMessageTask implements Runnable
 {
-    private Player player;
-    private ChatColor color;
-    private String message;
+    private final Player player;
+    private final ChatColor color;
+    private final String message;
 
     public SendPlayerMessageTask(Player player, ChatColor color, String message)
     {

src/main/java/me/ryanhamshire/GriefPrevention/SiegeCheckupTask.java

@@ -24,7 +24,7 @@ import org.bukkit.entity.Player;
 //for example, defender escaped or attacker gave up and left
 class SiegeCheckupTask implements Runnable
 {
-    private SiegeData siegeData;
+    private final SiegeData siegeData;
 
     public SiegeCheckupTask(SiegeData siegeData)
     {

src/main/java/me/ryanhamshire/GriefPrevention/SpamDetector.java

@@ -230,7 +230,7 @@ class ChatterData
     public boolean spamWarned = false;              //whether the player has received a warning recently
 
     //all recent message lengths and their total
-    private ConcurrentLinkedQueue<LengthTimestampPair> recentMessageLengths = new ConcurrentLinkedQueue<>();
+    private final ConcurrentLinkedQueue<LengthTimestampPair> recentMessageLengths = new ConcurrentLinkedQueue<>();
     private int recentTotalLength = 0;
 
     public void AddMessage(String message, long timestamp)

src/main/java/me/ryanhamshire/GriefPrevention/VisualizationApplicationTask.java

@@ -23,9 +23,9 @@ import org.bukkit.entity.Player;
 //applies a visualization for a player by sending him block change packets
 class VisualizationApplicationTask implements Runnable
 {
-    private Visualization visualization;
-    private Player player;
-    private PlayerData playerData;
+    private final Visualization visualization;
+    private final Player player;
+    private final PlayerData playerData;
 
     public VisualizationApplicationTask(Player player, PlayerData playerData, Visualization visualization)
     {

src/main/java/me/ryanhamshire/GriefPrevention/VisualizationReversionTask.java

@@ -27,9 +27,9 @@ import java.util.Collections;
 //applies a visualization for a player by sending him block change packets
 class VisualizationReversionTask implements Runnable
 {
-    private Visualization visualization;
-    private Player player;
-    private PlayerData playerData;
+    private final Visualization visualization;
+    private final Player player;
+    private final PlayerData playerData;
 
     public VisualizationReversionTask(Player player, PlayerData playerData, Visualization visualization)
     {

src/main/java/me/ryanhamshire/GriefPrevention/WelcomeTask.java

@@ -9,7 +9,7 @@ import org.bukkit.inventory.meta.BookMeta;
 
 public class WelcomeTask implements Runnable
 {
-    private Player player;
+    private final Player player;
 
     public WelcomeTask(Player player)
     {

src/main/java/me/ryanhamshire/GriefPrevention/events/AccrueClaimBlocksEvent.java

@@ -26,7 +26,7 @@ public class AccrueClaimBlocksEvent extends Event
         return handlers;
     }
 
-    private Player player;
+    private final Player player;
     private int blocksToAccrue;
     private boolean isIdle = false;
     private boolean cancelled = false;

src/main/java/me/ryanhamshire/GriefPrevention/events/ClaimDeletedEvent.java

@@ -21,7 +21,7 @@ public class ClaimDeletedEvent extends Event
         return handlers;
     }
 
-    private Claim claim;
+    private final Claim claim;
 
     public ClaimDeletedEvent(Claim claim)
     {

src/main/java/me/ryanhamshire/GriefPrevention/events/ClaimModifiedEvent.java

@@ -24,7 +24,7 @@ public class ClaimModifiedEvent extends Event implements Cancellable
 
     private final Claim from;
     private final Claim to;
-    private CommandSender modifier;
+    private final CommandSender modifier;
     private boolean cancelled;
 
     public ClaimModifiedEvent(Claim from, Claim to, CommandSender modifier)

src/main/java/me/ryanhamshire/GriefPrevention/events/PlayerKickBanEvent.java

@@ -25,10 +25,10 @@ public class PlayerKickBanEvent extends Event
         return handlers;
     }
 
-    private Player player;
-    private String reason;
-    private String source;
-    private boolean ban;
+    private final Player player;
+    private final String reason;
+    private final String source;
+    private final boolean ban;
     private boolean cancelled = false;
 
     /**

src/main/java/me/ryanhamshire/GriefPrevention/events/PreventBlockBreakEvent.java

@@ -10,7 +10,7 @@ public class PreventBlockBreakEvent extends Event implements Cancellable
 {
     private static final HandlerList handlers = new HandlerList();
     private boolean cancelled = false;
-    private BlockBreakEvent innerEvent;
+    private final BlockBreakEvent innerEvent;
 
     public static HandlerList getHandlerList()
     {

src/main/java/me/ryanhamshire/GriefPrevention/metrics/Metrics.java

@@ -50,7 +50,7 @@ public class Metrics {
     private static final String URL = "https://bStats.org/submitData/bukkit";
 
     // Is bStats enabled on this server?
-    private boolean enabled;
+    private final boolean enabled;
 
     // Should failed requests be logged?
     private static boolean logFailedRequests;

src/main/java/me/ryanhamshire/GriefPrevention/metrics/MetricsHandler.java

@@ -13,7 +13,7 @@ import java.util.concurrent.Callable;
  */
 public class MetricsHandler
 {
-    private Metrics metrics;
+    private final Metrics metrics;
 
     public MetricsHandler(GriefPrevention plugin, String dataMode)
     {