feat: 메인 컨트롤러 기능 구현

src/main/java/org/yj/sejongauth/controller/Sj.java

@@ -0,0 +1,21 @@
+package org.yj.sejongauth.controller;
+
+import org.yj.sejongauth.domain.AuthService;
+import org.yj.sejongauth.domain.LoginReq;
+import org.yj.sejongauth.domain.ProfileRes;
+import org.yj.sejongauth.domain.ProfileService;
+
+public class Sj {
+
+    private static final AuthService authService = new AuthService();
+    private static final ProfileService PROFILE_SERVICE = new ProfileService();
+
+    public static ProfileRes login(LoginReq loginReq) {
+        if (authService.authenticate(loginReq)) {
+            String jsessionId = authService.getJsessionId();
+            return PROFILE_SERVICE.fetchUserProfile(jsessionId);
+        } else {
+            throw new RuntimeException("인증에 실패하였습니다.");
+        }
+    }
+}