follow+sendMessage

Change-Id: I3e9bbcc89dfc53b9651fd8722da1b445a597629a
diff --git a/src/main/java/com/example/g8backend/service/IUserService.java b/src/main/java/com/example/g8backend/service/IUserService.java
index af94d27..1f178f8 100644
--- a/src/main/java/com/example/g8backend/service/IUserService.java
+++ b/src/main/java/com/example/g8backend/service/IUserService.java
@@ -1,11 +1,25 @@
 package com.example.g8backend.service;
 
 import com.baomidou.mybatisplus.extension.service.IService;
+import com.example.g8backend.entity.Message;
 import com.example.g8backend.entity.User;
 import org.apache.ibatis.annotations.Param;
 
+import java.util.List;
+
 public interface IUserService extends IService<User> {
     User getUserByName(@Param("name") String name);
     User getUserByEmail(@Param("email") String email);
     User getUserByPasskey(@Param("passkey") String passkey);
+
+    // 关注功能
+    boolean followUser(Long followerId, Long followedId);
+    boolean unfollowUser(Long followerId, Long followedId);
+    List<User> getFollowings(Long userId);
+    List<User> getFollowers(Long userId);
+
+    // 私信功能
+    Long sendMessage(Long senderId, Long receiverId, String content);
+    List<Message> getMessages(Long userId, Long partnerId);
+    List<Message> getMessageHistory(Long userId);
 }