Created a Discord Subscription representation as well as a method for…

src/main/java/net/dv8tion/jda/api/JDA.java

@@ -27,6 +27,7 @@
 import net.dv8tion.jda.api.entities.emoji.CustomEmoji;
 import net.dv8tion.jda.api.entities.emoji.RichCustomEmoji;
 import net.dv8tion.jda.api.entities.sticker.*;
+import net.dv8tion.jda.api.entities.subscription.Subscription;
 import net.dv8tion.jda.api.events.GenericEvent;
 import net.dv8tion.jda.api.hooks.IEventManager;
 import net.dv8tion.jda.api.interactions.commands.Command;
@@ -2122,6 +2123,32 @@ default RestAction<Void> deleteTestEntitlement(@Nonnull String entitlementId)
     @CheckReturnValue
     RestAction<Void> deleteTestEntitlement(long entitlementId);
 
+    /**
+     * Retrieves a List of {@link Subscription} by sku id
+     *
+     * @param skuId
+     *        The sku id of the List
+     * @return {@link RestAction} - Type: {@link Subscription}
+     *         <br>The list of subscriptions by provided sku id
+     */
+    @Nonnull
+    @CheckReturnValue
+    RestAction<Subscription> retrieveSubscriptionsBySkuId(long skuId);
+
+    /**
+     * Retrieves a {@link Subscription} by its id and sku id
+     *
+     * @param skuId
+     *        The sku id of the List where to find subscription
+     * @param subscriptionId
+     *        The id of the subscription to retrieve
+     * @return {@link RestAction} - Type: {@link Subscription}
+     *         <br> The Subscription with the provided id
+     */
+    @Nonnull
+    @CheckReturnValue
+    RestAction<Subscription> retrieveSubscriptionBySkuIdAndSubscriptionId(long skuId, long subscriptionId);
+
     /**
      * Configures the required scopes applied to the {@link #getInviteUrl(Permission...)} and similar methods.
      * <br>To use slash commands you must add {@code "applications.commands"} to these scopes. The scope {@code "bot"} is always applied.

src/main/java/net/dv8tion/jda/api/entities/subscription/Subscription.java

@@ -0,0 +1,131 @@
+package net.dv8tion.jda.api.entities.subscription;
+
+import net.dv8tion.jda.api.entities.ISnowflake;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.time.OffsetDateTime;
+import java.util.List;
+import java.util.stream.Collectors;
+
+/**
+ * Representation of a Discord Subscription
+ *
+ * @see <a href="https://discord.com/developers/docs/resources/subscription" target="_blank">Discord Docs about Subscriptions</a>
+ */
+public interface Subscription extends ISnowflake
+{
+    /**
+     * The user who subscribed
+     *
+     * @return a use who subscribed
+     */
+    @Nonnull
+    long getSubscriberIdLong();
+
+    /**
+     * The user who subscribed
+     *
+     * @return a use who subscribed
+     */
+    @Nonnull
+    default String getSubscriberId()
+    {
+        return Long.toUnsignedString(getSubscriberIdLong());
+    }
+
+    /**
+     * The sku id's related to this
+     *
+     * @return The list of sku id's related to this {@link Subscription}
+     */
+    @Nonnull
+    List<Long> getSkuIdsLong();
+
+    /**
+     * The sku id's related to this
+     *
+     * @return The list sku id's related to this {@link Subscription}
+     */
+    @Nonnull
+    default List<String> getSkuIds()
+    {
+        return getSkuIdsLong().stream()
+                .map(Long::toUnsignedString)
+                .collect(Collectors.toList());
+    }
+
+    /**
+     * The entitlements id's related to this {@link Subscription}
+     *
+     * @return The sku id's related to this {@link Subscription}
+     */
+    @Nonnull
+    List<Long> getEntitlementIdsLong();
+
+    /**
+     * The entitlements id's related to this {@link Subscription}
+     *
+     * @return The entitlements id's related to this {@link Subscription}
+     */
+    @Nonnull
+    default List<String> getEntitlementIds()
+    {
+        return getEntitlementIdsLong().stream()
+                .map(Long::toUnsignedString)
+                .collect(Collectors.toList());
+    }
+
+    /**
+     * The renewal sku id's related to this {@link Subscription}
+     *
+     * @return The  renewal sku id's related to this {@link Subscription}
+     */
+    @Nullable
+    List<Long> getRenewalSkuIdsLong();
+
+    /**
+     * The renewal sku id's related to this {@link Subscription}
+     *
+     * @return The  renewal sku id's related to this {@link Subscription}
+     */
+    @Nullable
+    default List<String> getRenewalSkuIds()
+    {
+        return getRenewalSkuIdsLong().stream()
+                .map(Long::toUnsignedString)
+                .collect(Collectors.toList());
+    }
+
+    /**
+     * The start of period of this {@link Subscription}
+     *
+     * @return The start of period of this {@link Subscription}
+     */
+    @Nonnull
+    OffsetDateTime getCurrentPeriodStart();
+
+    /**
+     * The end of period of this {@link Subscription}
+     *
+     * @return The end of period of this {@link Subscription}
+     */
+    @Nonnull
+    OffsetDateTime getCurrentPeriodEnd();
+
+    /**
+     * The canceled time of this {@link Subscription}
+     *
+     * @return The canceled time of this {@link Subscription}
+     */
+    @Nullable
+    OffsetDateTime getCanceledAt();
+
+    /**
+     * The status of this {@link Subscription}
+     *
+     * @return The status of this {@link Subscription}
+     */
+    @Nonnull
+    SubscriptionStatus getStatus();
+}

src/main/java/net/dv8tion/jda/api/entities/subscription/SubscriptionImpl.java

@@ -0,0 +1,114 @@
+package net.dv8tion.jda.api.entities.subscription;
+
+import net.dv8tion.jda.internal.utils.EntityString;
+import org.jetbrains.annotations.NotNull;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.time.OffsetDateTime;
+import java.util.List;
+
+
+public class SubscriptionImpl implements Subscription
+{
+    private final long id;
+    private final long subscriberId;
+    private final List<Long> skuIDs;
+    private final List<Long> entitlementIDs;
+    private final List<Long> renewalSkuIDs;
+    private final OffsetDateTime currentPeriodStart;
+    private final OffsetDateTime currentPeriodEnd;
+    private final OffsetDateTime canceledAt;
+    private final SubscriptionStatus status;
+
+    public SubscriptionImpl(final long id, final long subscriberId, @Nonnull final List<Long> skuIDs,
+                            @Nonnull final List<Long> entitlementIDs, @Nullable final List<Long> renewalSkuIDs,
+                            @Nonnull final OffsetDateTime currentPeriodStart, @Nonnull final OffsetDateTime currentPeriodEnd, @Nullable final OffsetDateTime canceledAt,
+                            @Nonnull final SubscriptionStatus status)
+    {
+
+        this.id = id;
+        this.subscriberId = subscriberId;
+        this.skuIDs = skuIDs;
+        this.entitlementIDs = entitlementIDs;
+        this.renewalSkuIDs = renewalSkuIDs;
+        this.currentPeriodStart = currentPeriodStart;
+        this.currentPeriodEnd = currentPeriodEnd;
+        this.canceledAt = canceledAt;
+        this.status = status;
+    }
+
+    @Nonnull
+    @Override
+    public long getIdLong()
+    {
+        return id;
+    }
+
+    public long getSubscriberIdLong()
+    {
+        return subscriberId;
+    }
+
+    public @NotNull List<Long> getSkuIdsLong()
+    {
+        return skuIDs;
+    }
+
+    public @NotNull List<Long> getEntitlementIdsLong()
+    {
+        return entitlementIDs;
+    }
+
+    public @Nullable List<Long> getRenewalSkuIdsLong()
+    {
+        return renewalSkuIDs;
+    }
+
+    public @NotNull OffsetDateTime getCurrentPeriodStart()
+    {
+        return currentPeriodStart;
+    }
+
+    public @NotNull OffsetDateTime getCurrentPeriodEnd()
+    {
+        return currentPeriodEnd;
+    }
+
+    public OffsetDateTime getCanceledAt()
+    {
+        return canceledAt;
+    }
+
+    public @NotNull SubscriptionStatus getStatus()
+    {
+        return status;
+    }
+
+    @Override
+    public int hashCode()
+    {
+        return Long.hashCode(id);
+    }
+
+    @Override
+    public boolean equals(Object obj)
+    {
+        if (this == obj)
+            return true;
+        if (!(obj instanceof SubscriptionImpl))
+        {
+            return false;
+        }
+        SubscriptionImpl other = (SubscriptionImpl) obj;
+        return other.id == this.id;
+    }
+
+    @Override
+    public String toString()
+    {
+        return new EntityString(this)
+                .addMetadata("id", id)
+                .toString();
+    }
+}

src/main/java/net/dv8tion/jda/api/entities/subscription/SubscriptionStatus.java

@@ -0,0 +1,47 @@
+package net.dv8tion.jda.api.entities.subscription;
+
+import javax.annotation.Nonnull;
+
+/**
+ * Representation of a Discord Subscription Status
+ *
+ * @see <a href="https://discord.com/developers/docs/resources/subscription#subscription-statuses" target="_blank">Discord Docs about Subscription Statuses</a>
+ */
+public enum SubscriptionStatus
+{
+    UNKNOWN(-1), ACTIVE(0), ENDING(1), INACTIVE(2);
+
+    private final int id;
+
+    SubscriptionStatus(int id)
+    {
+        this.id = id;
+    }
+
+    /**
+     * Gets the Subscription status related to the provided key.
+     * <br>If an unknown key is provided, this returns {@link #UNKNOWN}
+     *
+     * @param  key
+     *         The Discord key referencing a Subscription status.
+     *
+     * @return The Subscription status that has the key provided, or {@link #UNKNOWN} for unknown key.
+     */
+    @Nonnull
+    public static SubscriptionStatus fromKey(int key)
+    {
+        for (SubscriptionStatus status : values())
+        {
+            if (status.id == key)
+            {
+                return status;
+            }
+        }
+        return UNKNOWN;
+    }
+
+    public int getId()
+    {
+        return id;
+    }
+}

src/main/java/net/dv8tion/jda/api/events/subscription/GenericSubscriptionEvent.java

@@ -0,0 +1,36 @@
+package net.dv8tion.jda.api.events.subscription;
+
+import net.dv8tion.jda.api.JDA;
+import net.dv8tion.jda.api.entities.subscription.Subscription;
+import net.dv8tion.jda.api.events.Event;
+
+import javax.annotation.Nonnull;
+
+/**
+ * Indicates that an {@link Subscription Subscription} was either created, updated, or deleted
+ *
+ * @see SubscriptionCreateEvent
+ * @see SubscriptionUpdateEvent
+ * @see SubscriptionDeleteEvent
+ */
+public abstract class GenericSubscriptionEvent extends Event
+{
+    protected final Subscription subscription;
+
+    protected GenericSubscriptionEvent(@Nonnull JDA api, long responseNumber, @Nonnull Subscription subscription)
+    {
+        super(api, responseNumber);
+        this.subscription = subscription;
+    }
+
+    /**
+     * The subscription {@link Subscription}
+     *
+     * @return The subscription {@link Subscription}
+     */
+    @Nonnull
+    public Subscription getSubscription()
+    {
+        return subscription;
+    }
+}

src/main/java/net/dv8tion/jda/api/events/subscription/SubscriptionCreateEvent.java

@@ -0,0 +1,15 @@
+package net.dv8tion.jda.api.events.subscription;
+
+import net.dv8tion.jda.api.JDA;
+import net.dv8tion.jda.api.entities.subscription.Subscription;
+
+/**
+ * Indicate that a Subscription for Premium app was created
+ */
+public class SubscriptionCreateEvent extends GenericSubscriptionEvent
+{
+    public SubscriptionCreateEvent(JDA api, long responseNumber, Subscription subscription)
+    {
+        super(api, responseNumber, subscription);
+    }
+}