improve BanList types

paper-api/src/main/java/io/papermc/paper/ban/BanListType.java

@@ -0,0 +1,30 @@
+package io.papermc.paper.ban;
+
+import org.bukkit.BanList;
+import org.bukkit.ban.IpBanList;
+import org.bukkit.ban.ProfileBanList;
+import org.jspecify.annotations.NullMarked;
+
+/**
+ * Represents a ban-type that a {@link BanList} may track.
+ * It enforces the correct return value at compile time.
+ */
+@NullMarked
+public interface BanListType<T> {
+
+    /**
+     * Banned IP addresses
+     */
+    BanListType<IpBanList> IP = new BanListTypeImpl<>(IpBanList.class);
+    /**
+     * Banned player profiles
+     */
+    BanListType<ProfileBanList> PROFILE = new BanListTypeImpl<>(ProfileBanList.class);
+
+    /**
+     * Returns the type class of the ban list used generically
+     *
+     * @return the type class
+     */
+    Class<T> typeClass();
+}

paper-api/src/main/java/io/papermc/paper/ban/BanListTypeImpl.java

@@ -0,0 +1,9 @@
+package io.papermc.paper.ban;
+
+import org.jetbrains.annotations.ApiStatus;
+import org.jspecify.annotations.NullMarked;
+
+@ApiStatus.Internal
+@NullMarked
+record BanListTypeImpl<T>(Class<T> typeClass) implements BanListType<T> {
+}

paper-api/src/main/java/org/bukkit/BanList.java

@@ -16,7 +16,9 @@ public interface BanList<T> {
 
     /**
      * Represents a ban-type that a {@link BanList} may track.
+     * @deprecated use {@link io.papermc.paper.ban.BanListType} to enforce the correct return value at compile time.
      */
+    @Deprecated(since = "1.20.4") // Paper - BanList Type Improvements
     public enum Type {
         /**
          * Banned player names

paper-api/src/main/java/org/bukkit/Bukkit.java

@@ -1663,11 +1663,27 @@ public final class Bukkit {
      * @param <T> The ban target
      *
      * @return a ban list of the specified type
+     * @deprecated use {@link #getBanList(io.papermc.paper.ban.BanListType)} to enforce the correct return value at compile time.
      */
     @NotNull
+    @Deprecated(since = "1.20.4") // Paper - add BanListType (which has a generic)
     public static <T extends BanList<?>> T getBanList(@NotNull BanList.Type type) {
         return server.getBanList(type);
     }
+    // Paper start - add BanListType (which has a generic)
+    /**
+     * Gets a ban list for the supplied type.
+     *
+     * @param type the type of list to fetch, cannot be null
+     * @param <B> The ban target
+     *
+     * @return a ban list of the specified type
+     */
+    @NotNull
+    public static <B extends BanList<E>, E> B getBanList(final io.papermc.paper.ban.@NotNull BanListType<B> type) {
+        return server.getBanList(type);
+    }
+    // Paper end - add BanListType (which has a generic)
 
     /**
      * Gets a set containing all player operators.

paper-api/src/main/java/org/bukkit/Server.java

@@ -1425,10 +1425,25 @@ public interface Server extends PluginMessageRecipient, net.kyori.adventure.audi
      * @param <T> The ban target
      *
      * @return a ban list of the specified type
+     * @deprecated use {@link #getBanList(io.papermc.paper.ban.BanListType)} to enforce the correct return value at compile time.
      */
+    @Deprecated // Paper - add BanListType (which has a generic)
     @NotNull
     public <T extends BanList<?>> T getBanList(@NotNull BanList.Type type);
 
+    // Paper start - add BanListType (which has a generic)
+    /**
+     * Gets a ban list for the supplied type.
+     *
+     * @param type the type of list to fetch, cannot be null
+     * @param <B> The ban target
+     *
+     * @return a ban list of the specified type
+     */
+    @NotNull
+    <B extends BanList<E>, E> B getBanList(@NotNull io.papermc.paper.ban.BanListType<B> type);
+    // Paper end - add BanListType (which has a generic)
+
     /**
      * Gets a set containing all player operators.
      *