Version 1.3.0

 * Updated to `api-version` 1.18
 * Store current stage number and next stage (during
   transition) in `config.yml` rather than trying to
   infer the stage number from the presence of
   entities. This should be more reliable.

pom.xml

@@ -5,7 +5,7 @@
 
     <groupId>nu.nerd</groupId>
     <artifactId>DragonFight</artifactId>
-    <version>1.2.0</version>
+    <version>1.3.0</version>
 
     <description>Custom dragon fight.</description>
     <url>https://github.com/NerdNu/${project.name}</url>
@@ -17,8 +17,17 @@
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
+        <!--
+            See: https://mkyong.com/maven/maven-error-invalid-target-release-17/
+            You will need to tell Maven to use Java 17.
+            Do: mvn -version to check the version of Java used by Maven.
+            Then set JAVA_HOME as appropriate to your platform:
+            export JAVA_HOME=/usr/lib/jvm/java-17-openjdk
+        -->
+        <maven.compiler.release>17</maven.compiler.release>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+        <maven.compiler.showDeprecation>true</maven.compiler.showDeprecation>
     </properties>
 
     <repositories>
@@ -32,12 +41,21 @@
         <dependency>
             <groupId>org.spigotmc</groupId>
             <artifactId>spigot-api</artifactId>
-            <version>1.15.2-R0.1-SNAPSHOT</version>
+            <version>1.18.1-R0.1-SNAPSHOT</version>
         </dependency>
         <dependency>
             <groupId>nu.nerd</groupId>
             <artifactId>BeastMaster</artifactId>
-            <version>2.14.0</version>
+            <version>2.17.0</version>
+        </dependency>
+        <dependency>
+            <!--
+                Work around java.lang.IllegalAccessError: class lombok.javac.apt.LombokProcessor
+                for whatever is using it: Minecraft? Spigot?
+            -->
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>1.18.20</version>
         </dependency>
     </dependencies>
 
@@ -49,5 +67,13 @@
                 <filtering>true</filtering>
             </resource>
         </resources>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.9.0</version>
+            </plugin>
+        </plugins>
     </build>
 </project>
+

src/main/java/nu/nerd/df/Configuration.java

@@ -24,13 +24,38 @@ public class Configuration {
      */
     public String DEBUG_PREFIX;
 
+    /**
+     * Current stage number: 0 to 11.
+     *
+     * Stage 0 is before the fight, Stage 1 => first crystal removed and boss
+     * spawned. Stage 10 => final boss spawned. Stage 11: dragon. In Stage N, N
+     * crystals have been removed.
+     */
+    public int STAGE_NUMBER;
+
+    /**
+     * The new value of STAGE_NUMBER, when there is a transition between stages.
+     *
+     * Spawn animations for the dragon and for stage bosses take time. To handle
+     * server restarts during these spawn sequences, we need to record the fact
+     * that it is underway and at least the new stage number. But in this
+     * plugin, we record both as that makes backwards stage transitions feasible
+     * (although not currently implemented).
+     *
+     * When NEW_STAGE_NUMBER != STAGE_NUMBER, the fight is part-way through
+     * transitioning from STAGE_NUMBER to NEW_STAGE_NUMBER. The STAGE_NUMBER
+     * will be set to NEW_STAGE_NUMBER when the transition is complete, in a few
+     * seconds.
+     */
+    public int NEW_STAGE_NUMBER;
+
     /**
      * Total boss maximum health.
      *
      * This needs to be preserved across restarts, since a stage fight may have
-     * a random number of bosses, some of which may have died. THere is no easy
-     * way to work infer the total maximum boss health points in the stage after
-     * a restart.
+     * a random number of bosses, some of which may have died. There is no easy
+     * way to infer the total maximum boss health points in the stage after a
+     * restart.
      */
     public double TOTAL_BOSS_MAX_HEALTH;
 
@@ -102,15 +127,18 @@ public Stage getStage(int stageNumber) {
 
     // ------------------------------------------------------------------------
     /**
-     * Reload the configuration.
+     * Reload the fight state.
+     *
+     * The fight state changes as the plugin runs, so only call this method when
+     * loading the plugin.
      */
-    public void reload() {
+    public void reloadFightState() {
         DragonFight.PLUGIN.reloadConfig();
         FileConfiguration config = DragonFight.PLUGIN.getConfig();
         Logger logger = DragonFight.PLUGIN.getLogger();
 
-        LOG_PREFIX = config.getString("settings.log-prefix");
-        DEBUG_PREFIX = config.getString("settings.debug-prefix");
+        STAGE_NUMBER = config.getInt("state.stage-number", 0);
+        NEW_STAGE_NUMBER = config.getInt("state.new-stage-number", 0);
 
         TOTAL_BOSS_MAX_HEALTH = config.getDouble("state.total-boss-max-health");
         try {
@@ -131,6 +159,22 @@ public void reload() {
                 logger.warning("Unclaimed dragon prize registered to invalid UUID: " + key);
             }
         }
+    }
+
+    // ------------------------------------------------------------------------
+    /**
+     * Reload the configuration.
+     *
+     * This method is the counterpart to {@link #reloadFightState}. This method
+     * only loads the settings of the fight that are not modified as the fight
+     * progresses.
+     */
+    public void reloadConfiguration() {
+        DragonFight.PLUGIN.reloadConfig();
+        FileConfiguration config = DragonFight.PLUGIN.getConfig();
+
+        LOG_PREFIX = config.getString("settings.log-prefix");
+        DEBUG_PREFIX = config.getString("settings.debug-prefix");
 
         for (int stageNumber = 1; stageNumber <= 11; ++stageNumber) {
             getStage(stageNumber).load(getStageSection(stageNumber));
@@ -147,6 +191,8 @@ public void save() {
         config.set("settings.log-prefix", LOG_PREFIX);
         config.set("settings.debug-prefix", DEBUG_PREFIX);
 
+        config.set("state.stage-number", STAGE_NUMBER);
+        config.set("state.new-stage-number", NEW_STAGE_NUMBER);
         config.set("state.total-boss-max-health", TOTAL_BOSS_MAX_HEALTH);
         config.set("state.fight-owner", (FIGHT_OWNER == null) ? null : FIGHT_OWNER.toString());
 

src/main/java/nu/nerd/df/DragonFight.java

@@ -38,7 +38,8 @@ public class DragonFight extends JavaPlugin {
     public void onEnable() {
         PLUGIN = this;
         saveDefaultConfig();
-        CONFIG.reload();
+        CONFIG.reloadConfiguration();
+        CONFIG.reloadFightState();
 
         addCommandExecutor(new DFExecutor());
         addCommandExecutor(new DragonExecutor());
@@ -61,7 +62,7 @@ public void onDisable() {
     // ------------------------------------------------------------------------
     /**
      * Add the specified CommandExecutor and set it as its own TabCompleter.
-     * 
+     *
      * @param executor the CommandExecutor.
      */
     protected void addCommandExecutor(ExecutorBase executor) {

src/main/java/nu/nerd/df/DragonUtil.java

@@ -16,15 +16,15 @@
 // --------------------------------------------------------------------------
 /**
  * DragonFight utility functions.
- * 
+ *
  * Note that the DragonFight plugin also references BeastMaster's DragonUtil
  * class, so to avoid a qualified name, we name this class differently.
  */
 public class DragonUtil {
     // ------------------------------------------------------------------------
     /**
      * Return the world where the dragon fight occurs.
-     * 
+     *
      * @return the world where the dragon fight occurs.
      */
     public static World getFightWorld() {
@@ -35,7 +35,7 @@ public static World getFightWorld() {
     /**
      * Return true if the specified world is the one where the dragon fight can
      * occur.
-     * 
+     *
      * @param world the world.
      * @return true if the specified world is the one where the dragon fight can
      *         occur.
@@ -48,9 +48,9 @@ public static boolean isFightWorld(World world) {
     // ------------------------------------------------------------------------
     /**
      * Remove a specific dragon.
-     * 
+     *
      * Because Entity.remove() would be too easy.
-     * 
+     *
      * @param dragon the ender dragon to remove.
      */
     public static void removeDragon(EnderDragon dragon) {
@@ -77,9 +77,9 @@ public static void removeAllDragons() {
     /**
      * Return true if an entity has the specified scoreboard tag or BeastMaster
      * group.
-     * 
+     *
      * @param entity the entity.
-     * @param tag the tag or group to look for.
+     * @param tag    the tag or group to look for.
      * @return true if the entity has the tag or group.
      */
     public static boolean hasTagOrGroup(Entity entity, String tag) {
@@ -102,7 +102,7 @@ public static boolean hasTagOrGroup(Entity entity, String tag) {
      * Return the magnitude of the X and Z components of location, i.e. the
      * distance between loc and the world origin in the XZ plane (ignoring Y
      * coordinate).
-     * 
+     *
      * @param loc the location.
      * @return sqrt(x^2 + z^2).
      */
@@ -114,11 +114,11 @@ public static double getMagnitude2D(Location loc) {
     /**
      * Return true if the specified location is on the circle where the centre
      * of the obsidian pillars are placed.
-     * 
+     *
      * The pillars about placed in a circle about 40 blocks from (0,0). The
      * largest pillars have a radius of 5 blocks, including the centre block, so
      * ensure that we block placements up to 6 blocks away (6/40 = 0.15).
-     * 
+     *
      * Note that:
      * <ul>
      * <li>This method assumes that the world has already been confirmed to be
@@ -129,19 +129,20 @@ public static double getMagnitude2D(Location loc) {
      * spawning of crystals on pillars, because when the crystal on the pillar
      * spawns, the block underneath it comes back as AIR, not BEDROCK.</li>
      * </ul>
-     * 
+     *
      * @param loc the location.
      * @return if the location is about the right range from the origin of the
      *         world to be the centre of a pillar.
      */
     public static boolean isOnPillarCircle(Location loc) {
-        return Math.abs(getMagnitude2D(loc) - DragonUtil.PILLAR_CIRCLE_RADIUS) < 0.15 * DragonUtil.PILLAR_CIRCLE_RADIUS;
+        return loc.getWorld().getName().equals("world_the_end") &&
+               Math.abs(getMagnitude2D(loc) - DragonUtil.PILLAR_CIRCLE_RADIUS) < 0.15 * DragonUtil.PILLAR_CIRCLE_RADIUS;
     }
 
     // ------------------------------------------------------------------------
     /**
      * The World where the fight occurs.
-     * 
+     *
      * It could be configurable, but for now is constant.
      */
     private static final String FIGHT_WORLD = "world_the_end";