finish handleAnnounce and fix bugs in torrent upload(using ISO_8859_1)

Change-Id: Ic2da7cef878bb7aa66184f04058bb2db2393190e
diff --git a/src/main/java/com/example/g8backend/service/ITrackerService.java b/src/main/java/com/example/g8backend/service/ITrackerService.java
index e522d77..055e317 100644
--- a/src/main/java/com/example/g8backend/service/ITrackerService.java
+++ b/src/main/java/com/example/g8backend/service/ITrackerService.java
@@ -1,6 +1,9 @@
 package com.example.g8backend.service;
 
 
-public interface ITrackerService {
+import com.example.g8backend.dto.AnnounceRequestDTO;
+import com.example.g8backend.dto.AnnounceResponseDTO;
 
+public interface ITrackerService {
+    AnnounceResponseDTO handleAnnounce(AnnounceRequestDTO requestDTO);
 }