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/AnnounceRequestDTO.java b/src/main/java/com/example/g8backend/dto/AnnounceRequestDTO.java
new file mode 100644
index 0000000..e54f06d
--- /dev/null
+++ b/src/main/java/com/example/g8backend/dto/AnnounceRequestDTO.java
@@ -0,0 +1,17 @@
+package com.example.g8backend.dto;
+
+import lombok.Data;
+
+@Data
+public class AnnounceRequestDTO {
+    private String passkey;
+    private String infoHash;
+    private String peerId;
+    private int port;
+    private double uploaded;
+    private double downloaded;
+    private double left;
+    private Integer compact; // 可选
+    private String event;    // 可选
+    private String ip;
+}