MuntashirAkon/AppManager · error · IOException

Message is too large:

Error message

Message is too large:

What it means

DataTransmission frames each message with a 4-byte length header, capped at MAX_MESSAGE_SIZE. sendMessage(byte[]) throws IOException when the payload exceeds that cap, before anything is written, to prevent protocol/frame corruption. The exception message includes the offending length.

Solutions

  1. Split the payload into chunks below MAX_MESSAGE_SIZE and reassemble at the receiver
  2. Compress the payload before sending
  3. Write large data to a file and send a path/reference instead of the bytes

Example fix

// before
transmission.sendMessage(hugeBytes);
// after
for (int i = 0; i < hugeBytes.length; i += MAX_MESSAGE_SIZE) {
    int n = Math.min(MAX_MESSAGE_SIZE, hugeBytes.length - i);
    byte[] chunk = Arrays.copyOfRange(hugeBytes, i, i + n);
    if (chunk.length == MAX_MESSAGE_SIZE) chunk[chunk.length-1] &= 0x7f; // obey encoder cap if needed
    transmission.sendMessage(chunk);
}
Defensive patterns

Strategy: validation

Validate before calling

if (messageBytes == null || messageBytes.length <= MAX_MESSAGE_SIZE) {
    transmission.sendMessage(messageBytes);
} else {
    // chunk or compress
}

Try / catch

try {
    transmission.sendMessage(bytes);
} catch (IOException e) {
    if (e.getMessage() != null && e.getMessage().startsWith("Message is too large")) {
        // chunk the payload and retry
    } else throw e;
}

Prevention

When it happens

Trigger: Calling sendMessage(byte[]) with an array larger than MAX_MESSAGE_SIZE (e.g. sending a whole file blob or oversized serialized object through the privileged-service channel).

Common situations: Streaming large command output or bulk data without chunking; a server reply that grows beyond the fixed frame limit; protocol misuse treating the channel as a raw stream.

Understand the failure class

Background: payload too large / request exceeds maximum size: why libraries cap bytes and how to fix oversize payloads — this error's family across 50 libraries.

Related errors

AI-assisted analysis of MuntashirAkon/AppManager@0152f468fc (2026-09-12). Data as JSON: /api/errors/47e2d5686887f9db. Report an issue: GitHub.

Appendix: source

Thrown at libserver/src/main/java/io/github/muntashirakon/AppManager/server/common/DataTransmission.java:119

     */
    public void sendMessage(@Nullable String text) throws IOException {
        if (text != null) {
            sendMessage(text.getBytes());
        }
    }

    /**
     * Send message as bytes
     *
     * @param messageBytes Bytes to be sent
     * @throws IOException When it fails to send the message
     * @see #sendMessage(String)
     * @see #sendAndReceiveMessage(byte[])
     */
    public void sendMessage(@Nullable byte[] messageBytes) throws IOException {
        if (messageBytes != null) {
            if (messageBytes.length > MAX_MESSAGE_SIZE) {
                throw new IOException("Message is too large: " + messageBytes.length);
            }
            mOutputStream.writeInt(messageBytes.length);
            mOutputStream.write(messageBytes);
            mOutputStream.flush();
        }
    }

    /**
     * Read response as bytes after sending a message
     *
     * @return The bytes to be read
     * @throws IOException When it fails to read the message
     */
    @NonNull
    private byte[] readMessage() throws IOException {
        int len = mInputStream.readInt();
        if (len < 0 || len > MAX_MESSAGE_SIZE) {
            throw new IOException("Invalid message length: " + len);

View on GitHub (pinned to 0152f468fc)