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

Change-Id: Ic2da7cef878bb7aa66184f04058bb2db2393190e
diff --git a/src/main/java/com/example/g8backend/dto/AnnounceResponseDTO.java b/src/main/java/com/example/g8backend/dto/AnnounceResponseDTO.java
new file mode 100644
index 0000000..bbb1dc8
--- /dev/null
+++ b/src/main/java/com/example/g8backend/dto/AnnounceResponseDTO.java
@@ -0,0 +1,16 @@
+package com.example.g8backend.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.util.List;
+import java.util.Map;
+
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class AnnounceResponseDTO {
+    private int interval;
+    private List<Map<String, Object>> peers;
+}