lingochamp/FileDownloader · error · IllegalStateException

please use #catchWarn instead

Error message

please use #catchWarn instead %d

What it means

A deprecation/contract guard in MessageSnapshotTaker: the called method no longer handles warning notifications (it only carries the id of the task). Clients must call #catchWarn instead; the %d is the download id being processed when the legacy path was hit.

Solutions

1. Replace calls to the old snapshot-taking method with MessageSnapshotTaker.catchWarn(task) to capture warning snapshots
2. Upgrade FileDownloader to a version where the download-flow dispatch uses catchWarn internally
3. If you implement a custom download flow, route warn callbacks through catchWarn rather than the deprecated method

When it happens

Trigger: Thrown at library/src/main/java/com/liulishuo/filedownloader/message/MessageSnapshotTaker.java:107 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of lingochamp/FileDownloader@6237a8cac1 (2026-09-08). Data as JSON: /api/errors/b08cc87d67cab967. Report an issue: GitHub.

Appendix: source

Thrown at library/src/main/java/com/liulishuo/filedownloader/message/MessageSnapshotTaker.java:107

    }

    public static MessageSnapshot takeBlockCompleted(MessageSnapshot snapshot) {
        if (snapshot.getStatus() != FileDownloadStatus.completed) {
            throw new IllegalStateException(
                    FileDownloadUtils.formatString("take block completed snapshot, must has "
                                    + "already be completed. %d %d",
                            snapshot.getId(), snapshot.getStatus()));
        }

        return new BlockCompleteMessage.BlockCompleteMessageImpl(snapshot);
    }

    public static MessageSnapshot take(byte status, FileDownloadModel model,
                                       DownloadStatusCallback.ProcessParams processParams) {
        final MessageSnapshot snapShot;
        final int id = model.getId();
        if (status == FileDownloadStatus.warn) {
            throw new IllegalStateException(FileDownloadUtils.
                    formatString("please use #catchWarn instead %d", id));
        }

        switch (status) {
            case FileDownloadStatus.pending:
                if (model.isLargeFile()) {
                    snapShot = new LargeMessageSnapshot.PendingMessageSnapshot(id,
                            model.getSoFar(), model.getTotal());
                } else {
                    snapShot = new SmallMessageSnapshot.PendingMessageSnapshot(id,
                            (int) model.getSoFar(), (int) model.getTotal());
                }
                break;
            case FileDownloadStatus.started:
                snapShot = new MessageSnapshot.StartedMessageSnapshot(id);
                break;
            case FileDownloadStatus.connected:
                final String filename = model.isPathAsDirectory() ? model.getFilename() : null;

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