SPIGOT-5496: API to create and manipulate hardcore worlds

src/main/java/org/bukkit/World.java

@@ -1464,6 +1464,24 @@ public interface World extends PluginMessageRecipient, Metadatable {
      */
     public boolean canGenerateStructures();
 
+    /**
+     * Gets whether the world is hardcore or not.
+     *
+     * In a hardcore world the difficulty is locked to hard.
+     *
+     * @return hardcore status
+     */
+    public boolean isHardcore();
+
+    /**
+     * Sets whether the world is hardcore or not.
+     *
+     * In a hardcore world the difficulty is locked to hard.
+     *
+     * @param hardcore Whether the world is hardcore
+     */
+    public void setHardcore(boolean hardcore);
+
     /**
      * Gets the world's ticks per animal spawns value
      * <p>

src/main/java/org/bukkit/WorldCreator.java

@@ -18,6 +18,7 @@ public class WorldCreator {
     private WorldType type = WorldType.NORMAL;
     private boolean generateStructures = true;
     private String generatorSettings = "";
+    private boolean hardcore = false;
 
     /**
      * Creates an empty WorldCreationOptions for the given world name
@@ -50,6 +51,7 @@ public class WorldCreator {
         generator = world.getGenerator();
         type = world.getWorldType();
         generateStructures = world.canGenerateStructures();
+        hardcore = world.isHardcore();
 
         return this;
     }
@@ -72,6 +74,7 @@ public class WorldCreator {
         type = creator.type();
         generateStructures = creator.generateStructures();
         generatorSettings = creator.generatorSettings();
+        hardcore = creator.hardcore();
 
         return this;
     }
@@ -271,6 +274,32 @@ public class WorldCreator {
         return generateStructures;
     }
 
+    /**
+     * Sets whether the world will be hardcore or not.
+     *
+     * In a hardcore world the difficulty will be locked to hard.
+     *
+     * @param hardcore Whether the world will be hardcore
+     * @return This object, for chaining
+     */
+    @NotNull
+    public WorldCreator hardcore(boolean hardcore) {
+        this.hardcore = hardcore;
+
+        return this;
+    }
+
+    /**
+     * Gets whether the world will be hardcore or not.
+     *
+     * In a hardcore world the difficulty will be locked to hard.
+     *
+     * @return hardcore status
+     */
+    public boolean hardcore() {
+        return hardcore;
+    }
+
     /**
      * Creates a world with the specified options.
      * <p>