Partow/Telegram-Final-Project
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Profile logic for UI

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This commit is contained in:
Partow
2025-09-04 18:58:57 +03:30
parent e49f4b5383
commit d6f9263847
5 changed files with 873 additions and 15 deletions
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src/main/java/org/to/telegramfinalproject/Server/ClientHandler.java
+613 -3
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@@ -12,6 +12,9 @@ import org.to.telegramfinalproject.Utils.GroupPermissionUtil;
import java.io.*;
import java.net.Socket;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.time.LocalDateTime;
import java.util.*;
@@ -20,6 +23,15 @@ public class ClientHandler implements Runnable {
private final AuthService authService = new AuthService();
private User currentUser;
// ClientHandler.java
private static void log(String msg) {
System.out.println(java.time.LocalDateTime.now() + " [ClientHandler] " + msg);
}
private static void logf(String fmt, Object... args) {
log(String.format(fmt, args));
}
public ClientHandler(Socket socket) {
this.socket = socket;
@@ -30,11 +42,73 @@ public class ClientHandler implements Runnable {
UUID userId = null;
try (
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
PrintWriter out = new PrintWriter(socket.getOutputStream(), true)
// InputStream rawIn = socket.getInputStream();
// OutputStream rawOut = socket.getOutputStream();
//
// BufferedReader in = new BufferedReader(new InputStreamReader(rawIn, java.nio.charset.StandardCharsets.UTF_8));
// PrintWriter out = new PrintWriter(new OutputStreamWriter(rawOut, java.nio.charset.StandardCharsets.UTF_8), true);
// DataInputStream dis = new DataInputStream(rawIn);
// DataOutputStream dos = new DataOutputStream(new BufferedOutputStream(rawOut));
// BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
// PrintWriter out = new PrintWriter(socket.getOutputStream(), true)
// BufferedInputStream bis = new BufferedInputStream(socket.getInputStream());
// DataInputStream dis = new DataInputStream(bis); //for binary headers
//PrintWriter out = new PrintWriter(new OutputStreamWriter(socket.getOutputStream(), java.nio.charset.StandardCharsets.UTF_8), true);
InputStream rawIn = socket.getInputStream();
OutputStream rawOut = socket.getOutputStream();
BufferedInputStream bis = new BufferedInputStream(rawIn);
BufferedOutputStream bos = new BufferedOutputStream(rawOut);
DataInputStream dis = new DataInputStream(bis);
DataOutputStream dos = new DataOutputStream(bos);
PrintWriter out = new PrintWriter(new OutputStreamWriter(bos, java.nio.charset.StandardCharsets.UTF_8), true);
) {
// DataInputStream bin = new DataInputStream(new BufferedInputStream(socket.getInputStream()));
String inputLine;
while ((inputLine = in.readLine()) != null) {
while ((inputLine = readUtf8Line(bis)) != null) {
String line = inputLine.trim();
if("AVATAR".equalsIgnoreCase(line)){
out.println(new JSONObject().put("status","ready").toString());
out.flush();
handleAvatarFrame(dis, out, this.currentUser.getInternal_uuid());
continue;
}
if ("MEDIA".equalsIgnoreCase(inputLine.trim())) {
handleMediaFrame(dis, out);
continue;
}
if ("MEDIA_DL".equalsIgnoreCase(line)) {
UUID cu = (currentUser == null ? null : currentUser.getInternal_uuid());
logf("MEDIA_DL received. currentUser.internal_uuid=%s", cu);
if (cu == null) {
log("MEDIA_DL rejected: currentUser is null or no internal_uuid");
sendDlErr(dos, "not authorized");
continue;
}
handleMediaDownload(dis, dos, cu);
continue;
}
JSONObject requestJson = new JSONObject(inputLine);
String action = requestJson.getString("action");
ResponseModel response = null;
@@ -3145,4 +3219,540 @@ public class ClientHandler implements Runnable {
}
private static final int MAGIC_AVATAR = 0x41565431; // "AVT1"
private static final long MAX_AVATAR = 3L * 1024 * 1024;
private void handleAvatarFrame(DataInputStream dis, PrintWriter out, UUID currentUserId) {
try {
int magic = dis.readInt();
if (magic != MAGIC_AVATAR) { out.println(err("bad magic")); out.flush(); return; }
int headerLen = dis.readInt();
if (headerLen <= 0 || headerLen > 64*1024) { out.println(err("bad header length")); out.flush(); return; }
byte[] headerBytes = dis.readNBytes(headerLen);
if (headerBytes.length != headerLen) { out.println(err("header truncated")); out.flush(); return; }
JSONObject h = new JSONObject(new String(headerBytes, java.nio.charset.StandardCharsets.UTF_8));
long contentLen = dis.readLong();
if (contentLen <= 0 || contentLen > MAX_AVATAR) {
skip(dis, contentLen);
out.println(err("file too large/invalid")); out.flush(); return;
}
String targetType = h.optString("target_type", "user").toLowerCase();
UUID targetId;
if ("user".equals(targetType)) {
String s = h.optString("target_id", "");
targetId = s.isEmpty() ? currentUserId : UUID.fromString(s);
if (!targetId.equals(currentUserId)) {
skip(dis, contentLen);
out.println(err("forbidden")); out.flush(); return;
}
} else {
String s = h.optString("target_id", "");
if (s.isEmpty()) { skip(dis, contentLen); out.println(err("missing target_id")); out.flush(); return; }
targetId = UUID.fromString(s);
if (!hasManagePermission(currentUserId, targetType, targetId)) {
skip(dis, contentLen);
out.println(err("forbidden")); out.flush(); return;
}
}
String fileName = h.optString("file_name", "avatar.bin");
String mimeType = h.optString("mime_type", "application/octet-stream");
if (!isAllowedImageMime(mimeType)) { skip(dis, contentLen); out.println(err("unsupported mime")); out.flush(); return; }
if (fileName.length() > 200) fileName = fileName.substring(0,200);
java.nio.file.Path baseDir = java.nio.file.Paths.get("uploads").toAbsolutePath().normalize();
String subdir = "avatars/" + java.time.LocalDate.now();
java.nio.file.Path dir = baseDir.resolve(subdir).normalize();
java.nio.file.Files.createDirectories(dir);
String ext = guessExt_Profile(fileName, mimeType); // ⬅️ این یکی را صدا بزن
String storedName = java.util.UUID.randomUUID() + ext;
java.nio.file.Path targetPath = dir.resolve(storedName).normalize();
try (OutputStream fos = new BufferedOutputStream(java.nio.file.Files.newOutputStream(
targetPath, java.nio.file.StandardOpenOption.CREATE, java.nio.file.StandardOpenOption.TRUNCATE_EXISTING))) {
long remaining = contentLen;
byte[] buf = new byte[8192];
while (remaining > 0) {
int toRead = (int)Math.min(buf.length, remaining);
int n = dis.read(buf, 0, toRead);
if (n == -1) throw new EOFException("stream ended early");
fos.write(buf, 0, n);
remaining -= n;
}
}
String requestId = h.optString("message_id", null); // ⬅️ اضافه
long fileSize = java.nio.file.Files.size(targetPath);
String fileUrl = "/" + subdir.replace('\\','/') + "/" + storedName; // /avatars/YYYY-MM-DD/uuid.jpg
boolean ok = updateProfileImageUrl(targetType, targetId, fileUrl);
JSONObject ack = new JSONObject()
.put("status", ok ? "success" : "error")
.put("message_id", requestId == null ? JSONObject.NULL : requestId) // ⬅️ اضافه
.put("target_type", targetType)
.put("target_id", targetId.toString())
.put("file_name", fileName)
.put("mime_type", mimeType)
.put("file_size", fileSize)
.put("display_url", fileUrl);
out.println(ack.toString());
out.flush();
if (ok) {
// (اختیاری) Broadcast به اعضای مرتبط
// broadcastProfileChange(targetType, targetId, fileUrl);
}
} catch (Exception e) {
e.printStackTrace();
out.println(err("exception"));
out.flush();
}
}
private static String err(String m) { return new JSONObject().put("status","error").put("message",m).toString(); }
private static boolean isAllowedImageMime(String mime) {
if (mime == null) return false;
return mime.equals("image/jpeg") || mime.equals("image/png") || mime.equals("image/webp");
}
private static String guessExt_Profile(String fileName, String mime) {
String lower = fileName.toLowerCase();
if (lower.endsWith(".jpg") || lower.endsWith(".jpeg")) return ".jpg";
if (lower.endsWith(".png")) return ".png";
if (lower.endsWith(".webp")) return ".webp";
return switch (mime) {
case "image/jpeg" -> ".jpg";
case "image/png" -> ".png";
case "image/webp" -> ".webp";
default -> ".bin";
};
}
private boolean updateProfileImageUrl(String targetType, UUID targetId, String url) {
String sql = switch (targetType) {
case "user" -> "UPDATE users SET image_url=? WHERE internal_uuid=?";
case "channel" -> "UPDATE channels SET image_url=? WHERE id=?";
case "group" -> "UPDATE groups SET image_url=? WHERE id=?";
default -> null;
};
if (sql == null) return false;
try (Connection c = ConnectionDb.connect(); PreparedStatement ps = c.prepareStatement(sql)) {
ps.setString(1, url);
ps.setObject(2, targetId);
return ps.executeUpdate() > 0;
} catch (SQLException e) { e.printStackTrace(); return false; }
}
private void handleMediaFrame(DataInputStream dis, PrintWriter out) {
try {
final int MAGIC_EXPECTED = 0x4D444D31; // "MDM1"
int magic = dis.readInt();
if (magic != MAGIC_EXPECTED) {
out.println(new JSONObject().put("status","error").put("message","bad magic").toString()); out.flush(); return;
}
int headerLen = dis.readInt();
if (headerLen <= 0 || headerLen > 64 * 1024) {
out.println(new JSONObject().put("status","error").put("message","bad header length").toString()); out.flush(); return;
}
byte[] headerBytes = dis.readNBytes(headerLen);
if (headerBytes.length != headerLen) {
out.println(new JSONObject().put("status","error").put("message","header truncated").toString()); out.flush(); return;
}
JSONObject h = new JSONObject(new String(headerBytes, java.nio.charset.StandardCharsets.UTF_8));
long contentLen = dis.readLong();
long MAX_MEDIA = 25L * 1024 * 1024;
if (contentLen <= 0 || contentLen > MAX_MEDIA) {
skip(dis, contentLen);
out.println(new JSONObject().put("status","error").put("message","file too large/invalid").toString()); out.flush(); return;
}
UUID messageId = UUID.fromString(h.getString("message_id"));
UUID senderId = UUID.fromString(h.getString("sender_id"));
String rType = h.getString("receiver_type"); // private/group/channel
UUID receiverId = UUID.fromString(h.getString("receiver_id"));
String messageType = h.getString("message_type").toUpperCase(); // IMAGE | AUDIO
if (!"IMAGE".equals(messageType) && !"AUDIO".equals(messageType)) {
skip(dis, contentLen);
out.println(new JSONObject().put("status","error").put("message","unsupported message_type").toString()); out.flush(); return;
}
String fileName = h.optString("file_name", "file.bin");
String mimeType = h.optString("mime_type", "application/octet-stream");
String text = h.optString("text", ""); // کپشن اختیاری
Integer width = h.has("width") && !h.isNull("width") ? h.getInt("width") : null;
Integer height = h.has("height") && !h.isNull("height") ? h.getInt("height") : null;
if (fileName.length() > 200) fileName = fileName.substring(0, 200);
java.nio.file.Path baseDir = java.nio.file.Paths.get("uploads").toAbsolutePath().normalize();
java.nio.file.Files.createDirectories(baseDir);
String kind = "IMAGE".equals(messageType) ? "images" : "audios";
String subdir = kind + "/" + java.time.LocalDate.now();
java.nio.file.Path dir = baseDir.resolve(subdir).normalize();
java.nio.file.Files.createDirectories(dir);
String ext = guessExt(fileName, mimeType);
String storedName = java.util.UUID.randomUUID() + ext;
java.nio.file.Path target = dir.resolve(storedName).normalize();
try (OutputStream fos = new BufferedOutputStream(java.nio.file.Files.newOutputStream(
target, java.nio.file.StandardOpenOption.CREATE, java.nio.file.StandardOpenOption.TRUNCATE_EXISTING))) {
long remaining = contentLen;
byte[] buf = new byte[8192];
while (remaining > 0) {
int toRead = (int) Math.min(buf.length, remaining);
int n = dis.read(buf, 0, toRead);
if (n == -1) throw new EOFException("stream ended early");
fos.write(buf, 0, n);
remaining -= n;
}
}
long fileSize = java.nio.file.Files.size(target);
String storagePath = target.toString();
String fileUrl = "/" + subdir.replace('\\','/') + "/" + storedName;
String mt = messageType; // "IMAGE" یا "AUDIO"
int safeWidth = ("IMAGE".equals(mt) && width != null) ? width : 0;
int safeHeight = ("IMAGE".equals(mt) && height != null) ? height : 0;
FileAttachment att = new FileAttachment();
att.setFileUrl(fileUrl);
att.setFileType(messageType); // IMAGE/AUDIO
att.setFileName(fileName);
att.setFileSize(fileSize);
att.setMimeType(mimeType);
att.setWidth(safeWidth);
att.setHeight(safeHeight);
att.setDurationSeconds(0);
att.setThumbnailUrl(null);
att.setStoragePath(storagePath);
java.util.List<FileAttachment> atts = java.util.List.of(att);
boolean ok = MessageDatabase.saveMessageWithOptionalAttachments(
messageId, senderId, receiverId, rType, text, messageType, atts
);
UUID mediaKey = null;
try (PreparedStatement q = ConnectionDb.connect().prepareStatement(
"SELECT media_key FROM message_attachments WHERE message_id = ? AND storage_path = ? LIMIT 1"
)) {
q.setObject(1, messageId);
q.setString(2, storagePath);
try (ResultSet rs = q.executeQuery()) {
if (rs.next()) mediaKey = (UUID) rs.getObject(1);
}
} catch (SQLException sqle) {
sqle.printStackTrace();
}
JSONObject ack = new JSONObject()
.put("status", ok ? "success" : "error")
.put("message_id", messageId.toString())
.put("media_key", mediaKey != null ? mediaKey.toString() : JSONObject.NULL)
.put("file_name", fileName)
.put("file_size", fileSize)
.put("mime_type", mimeType)
.put("display_path", fileUrl);
out.println(ack.toString());
out.flush();
// بعد از out.flush(); و فقط اگر ok==true
if (ok) {
try {
// 1) دریافت پیام از DB تا send_at و... دقیق باشد
Message m = MessageDatabase.findById(messageId); // اگر چنین متدی نداری، با پارامترهای همین متد بساز/پر کن
// 2) لیست دریافت‌کنندگان بر اساس نوع چت
List<UUID> receivers = getReceiversForChat(receiverId, rType.toLowerCase());
// 3) ساخت payload شامل اتچمنت (media)
User sender = userDatabase.findByInternalUUID(senderId);
JSONObject payload = new JSONObject()
.put("action", "new_message")
.put("data", new JSONObject()
.put("id", m.getMessage_id().toString())
.put("chat_id", receiverId.toString())
.put("chat_type", rType.toLowerCase())
.put("sender_id", senderId.toString())
.put("sender_name", sender != null ? sender.getProfile_name() : JSONObject.NULL)
.put("message_type", messageType.toLowerCase())
.put("text", (text == null || text.isEmpty()) ? JSONObject.NULL : text)
.put("media", new JSONObject()
.put("media_id", mediaKey != null ? mediaKey.toString() : JSONObject.NULL)
.put("file_name", fileName)
.put("mime_type", mimeType)
.put("size_bytes", fileSize)
.put("url", fileUrl)
.put("thumbnail_url", JSONObject.NULL)
.put("width", safeWidth)
.put("height", safeHeight)
.put("duration_ms", 0)
)
.put("send_at", m.getSend_at().toString())
.put("status", "SENT")
);
// 4) ارسال به همه اعضا (از جمله خودِ فرستنده اگر می‌خواهی UI آن هم یکپارچه آپدیت شود)
for (UUID uid : receivers) {
RealTimeEventDispatcher.sendToUser(uid, payload);
}
// (اختیاری) رویداد آپدیت چت‌لیست برای sort بر اساس آخرین پیام
RealTimeEventDispatcher.notifyChatUpdated(receiverId, rType, m);
} catch (Exception ex) {
ex.printStackTrace();
// اگر ذخیره شد ولی Broadcast شکست خورد، می‌توانی Log کنی یا Retry سبک انجام دهی
}
}
} catch (Exception e) {
e.printStackTrace();
out.println(new JSONObject().put("status","error").put("message","exception").toString());
out.flush();
}
}
private static final int MAGIC_DL = 0x4D444D32; // "MDM2"
// private void handleMediaDownload(DataInputStream inBin, DataOutputStream outBin, UUID requesterId) {
// try {
// int magic = inBin.readInt();
// if (magic != MAGIC_DL) { sendDlErr(outBin, "bad magic"); return; }
//
// int hlen = inBin.readInt();
// if (hlen <= 0 || hlen > 64 * 1024) { sendDlErr(outBin, "bad header length"); return; }
//
// byte[] hb = inBin.readNBytes(hlen);
// if (hb.length != hlen) { sendDlErr(outBin, "header truncated"); return; }
//
// JSONObject hdr = new JSONObject(new String(hb, java.nio.charset.StandardCharsets.UTF_8));
// if (!"download".equalsIgnoreCase(hdr.optString("op"))) { sendDlErr(outBin, "bad op"); return; }
//
// UUID mediaKey = UUID.fromString(hdr.getString("media_key"));
// long offset = Math.max(0L, hdr.optLong("offset", 0L));
//
// MediaRow mr = MessageDatabase.findMediaByKey(mediaKey);
// if (mr == null) { sendDlErr(outBin, "not found"); return; }
// if (!MessageDatabase.canAccess(requesterId, mr)) { sendDlErr(outBin, "not authorized"); return; }
//
// java.nio.file.Path path = java.nio.file.Paths.get(mr.storagePath).normalize();
// long size = java.nio.file.Files.size(path);
// if (offset > size) offset = 0L;
//
// JSONObject ok = new JSONObject()
// .put("status","success")
// .put("media_key", mediaKey.toString())
// .put("file_name", mr.fileName)
// .put("mime_type", mr.mimeType)
// .put("file_size", size);
//
// byte[] okb = ok.toString().getBytes(java.nio.charset.StandardCharsets.UTF_8);
//
// outBin.writeInt(MAGIC_DL);
// outBin.writeInt(okb.length);
// outBin.write(okb);
// outBin.writeLong(size - offset);
//
// try (java.io.InputStream fis = new java.io.BufferedInputStream(java.nio.file.Files.newInputStream(path))) {
// if (offset > 0) fis.skipNBytes(offset);
// byte[] buf = new byte[8192];
// long remain = size - offset;
// while (remain > 0) {
// int n = fis.read(buf, 0, (int) Math.min(buf.length, remain));
// if (n == -1) break;
// outBin.write(buf, 0, n);
// remain -= n;
// }
// }
// outBin.flush();
//
// } catch (Exception e) {
// e.printStackTrace();
// try { sendDlErr(outBin, "exception"); } catch (Exception ignored) {}
// }
// }
private void handleMediaDownload(DataInputStream inBin, DataOutputStream outBin, UUID requesterId) {
try {
logf("MEDIA_DL start. requester=%s", requesterId);
int magic = inBin.readInt();
if (magic != MAGIC_DL) { sendDlErr(outBin, "bad magic"); return; }
int hlen = inBin.readInt();
if (hlen <= 0 || hlen > 64 * 1024) { sendDlErr(outBin, "bad header length"); return; }
byte[] hb = inBin.readNBytes(hlen);
if (hb.length != hlen) { sendDlErr(outBin, "header truncated"); return; }
String hdrStr = new String(hb, java.nio.charset.StandardCharsets.UTF_8);
logf("MEDIA_DL header: %s", hdrStr);
JSONObject hdr = new JSONObject(hdrStr);
if (!"download".equalsIgnoreCase(hdr.optString("op"))) { sendDlErr(outBin, "bad op"); return; }
UUID mediaKey = UUID.fromString(hdr.getString("media_key"));
long offset = Math.max(0L, hdr.optLong("offset", 0L));
logf("Parsed mediaKey=%s offset=%d", mediaKey, offset);
MediaRow mr = MessageDatabase.findMediaByKey(mediaKey);
if (mr == null) { sendDlErr(outBin, "not found"); return; }
logf("MediaRow: chatType=%s chatId=%s sender=%s receiver=%s storage=%s",
mr.chatType, mr.chatId, mr.senderId, mr.receiverId, mr.storagePath);
try (java.sql.Connection c = ConnectionDb.connect();
java.sql.PreparedStatement st = c.prepareStatement(
"SELECT 1 FROM channel_subscribers WHERE channel_id = ? AND user_id = ? LIMIT 1")) {
st.setObject(1, mr.chatId, java.sql.Types.OTHER);
st.setObject(2, requesterId, java.sql.Types.OTHER);
boolean direct;
try (java.sql.ResultSet r = st.executeQuery()) { direct = r.next(); }
logf("[DL] direct channel membership ch=%s user=%s => %s", mr.chatId, requesterId, direct);
} catch (Exception e) {
logf("[DL] direct membership check ERROR: %s", e.toString());
}
boolean allowed = MessageDatabase.canAccess(requesterId, mr);
logf("canAccess(..) -> %s", allowed);
if (!allowed) { sendDlErr(outBin, "not authorized"); return; }
java.nio.file.Path path = java.nio.file.Paths.get(mr.storagePath).normalize();
long size = java.nio.file.Files.size(path);
if (offset > size) offset = 0L;
JSONObject ok = new JSONObject()
.put("status","success")
.put("media_key", mediaKey.toString())
.put("file_name", mr.fileName)
.put("mime_type", mr.mimeType)
.put("file_size", size);
byte[] okb = ok.toString().getBytes(java.nio.charset.StandardCharsets.UTF_8);
outBin.writeInt(MAGIC_DL);
outBin.writeInt(okb.length);
outBin.write(okb);
outBin.writeLong(size - offset);
logf("Sending OK header. file=%s size=%d offset=%d", mr.fileName, size, offset);
try (java.io.InputStream fis = new java.io.BufferedInputStream(java.nio.file.Files.newInputStream(path))) {
if (offset > 0) fis.skipNBytes(offset);
byte[] buf = new byte[8192];
long remain = size - offset;
while (remain > 0) {
int n = fis.read(buf, 0, (int) Math.min(buf.length, remain));
if (n == -1) break;
outBin.write(buf, 0, n);
remain -= n;
}
}
outBin.flush();
log("MEDIA_DL done.");
} catch (Exception e) {
e.printStackTrace();
try { sendDlErr(outBin, "exception"); } catch (Exception ignored) {}
}
}
private void sendDlErr(DataOutputStream outBin, String msg) throws java.io.IOException {
JSONObject j = new JSONObject().put("status","error").put("message", msg);
byte[] b = j.toString().getBytes(java.nio.charset.StandardCharsets.UTF_8);
outBin.writeInt(MAGIC_DL);
outBin.writeInt(b.length);
outBin.write(b);
outBin.writeLong(0L);
outBin.flush();
}
private static void skip(DataInputStream dis, long n) throws IOException {
if (n <= 0) return;
byte[] buf = new byte[8192];
long left = n;
while (left > 0) {
int toRead = (int) Math.min(buf.length, left);
int r = dis.read(buf, 0, toRead);
if (r == -1) break; // EOF
left -= r;
}
}
private static String guessExt(String original, String mime) {
if (original != null && original.contains(".")) {
String ext = original.substring(original.lastIndexOf('.'));
if (ext.length() <= 10) return ext.toLowerCase();
}
if (mime == null) return "";
String m = mime.toLowerCase();
if (m.equals("image/png")) return ".png";
if (m.equals("image/jpeg") || m.equals("image/jpg")) return ".jpg";
if (m.equals("image/gif")) return ".gif";
if (m.equals("image/webp")) return ".webp";
if (m.equals("audio/mpeg") || m.equals("audio/mp3")) return ".mp3";
if (m.equals("audio/ogg")) return ".ogg";
if (m.equals("audio/opus")) return ".opus";
if (m.equals("audio/wav") || m.equals("audio/x-wav")) return ".wav";
if (m.equals("audio/m4a") || m.equals("audio/mp4")) return ".m4a";
// if (m.equals("video/mp4")) return ".mp4";
// if (m.equals("video/webm")) return ".webm";
// fallback
if (m.startsWith("image/")) return "";
if (m.startsWith("audio/")) return "";
if (m.startsWith("video/")) return "";
return "";
}
private static String readUtf8Line(BufferedInputStream bis) throws java.io.IOException {
StringBuilder sb = new StringBuilder();
while (true) {
int b = bis.read();
if (b == -1) {
return sb.length() == 0 ? null : sb.toString();
}
if (b == '\n') {
int len = sb.length();
if (len > 0 && sb.charAt(len - 1) == '\r') sb.setLength(len - 1);
return sb.toString();
}
sb.append((char) b);
}
}
}