MuntashirAkon/AppManager · warning · UnsupportedOperationException

deleteOnExit() is not supported in RemoteFile

Error message

deleteOnExit() is not supported in RemoteFile

What it means

RemoteFile.deleteOnExit() unconditionally throws UnsupportedOperationException because delete-on-exit semantics require a JVM shutdown hook and an on-device File registry, which cannot be honored for files managed in a remote process. The library explicitly rejects the operation rather than silently ignoring it.

Solutions

1. Replace deleteOnExit() with explicit delete() calls at a well-defined point in your flow.
2. Track remote temp files in your own list and clean them up on shutdown/exit of your component.
3. Guard generic cleanup code with instanceof checks so RemoteFile paths use explicit deletion.
4. If using a File-agnostic helper, use tryDelete-style wrappers that skip unsupported operations.

Example fix

// before
remoteFile.deleteOnExit();
// after
runtime.addShutdownHook(new Thread(() -> remoteFile.delete()));

if (file instanceof RemoteFile) {
    // use explicit delete(); deleteOnExit() is unsupported
}

boolean supportsDeleteOnExit(Object f) {
    return !(f instanceof RemoteFile);
}

try {
    file.deleteOnExit();
} catch (UnsupportedOperationException e) {
    cleanupRegistry.add(file); // explicit delete later
}

When it happens

Trigger: Calling deleteOnExit() on any RemoteFile instance — always throws, regardless of path or state.

Common situations: Porting code written against java.io.File to RemoteFile and assuming API parity; temp-file cleanup utilities that call deleteOnExit generically on File-like abstractions.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• Android System (android) cannot be backed up.
• Flags must be returned by the corresponding subclasses. key
• Invalid key
• Invalid key
• Invalid key

AI-assisted analysis of MuntashirAkon/AppManager@0152f468fc (2026-09-12). Data as JSON: /api/errors/0030b5e0e27f9f69. Report an issue: GitHub.

Appendix: source

Thrown at libcore/io/src/main/java/io/github/muntashirakon/io/RemoteFile.java:312

        try {
            return fs.createLink(getPath(), target, true).tryAndGet();
        } catch (RemoteException e) {
            throw new IOException(e);
        }
    }

    @Override
    public boolean delete() {
        try {
            return fs.delete(getPath());
        } catch (RemoteException e) {
            return false;
        }
    }

    @Override
    public void deleteOnExit() {
        throw new UnsupportedOperationException("deleteOnExit() is not supported in RemoteFile");
    }

    @Override
    public String[] list() {
        try {
            StringParceledListSlice list = fs.list(getPath());
            return list != null ? list.getList().toArray(new String[0]) : null;
        } catch (RemoteException e) {
            return null;
        }
    }

    @Override
    public boolean mkdir() {
        try {
            return fs.mkdir(getPath());
        } catch (RemoteException e) {
            return false;

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