MuntashirAkon/AppManager · error · FileNotFoundException

Class definition for + node.getFullPath() + is not found.

Error message

Class definition for + node.getFullPath() + is not found.

What it means

DexFileSystem.getInputStream reads a class from a mounted DEX file. If the Node's ClassDef object is null — the node does not correspond to a class definition present in the DEX — a FileNotFoundException naming the node's full path is thrown before any class content can be read.

Source

Thrown at app/src/main/java/io/github/muntashirakon/io/fs/DexFileSystem.java:271

        boolean canAccess = true;
        if ((access & OsConstants.R_OK) != 0) {
            canAccess &= true;
        }
        if ((access & OsConstants.W_OK) != 0) {
            canAccess &= false;
        }
        if ((access & OsConstants.X_OK) != 0) {
            canAccess &= false;
        }
        return canAccess;
    }

    @NonNull
    @Override
    protected InputStream getInputStream(@NonNull Node<?> node) throws IOException {
        ClassDef classDef = (ClassDef) node.getObject();
        if (classDef == null) {
            throw new FileNotFoundException("Class definition for " + node.getFullPath() + " is not found.");
        }
        try {
            return new ByteArrayInputStream(getDexClasses().getClassContents(classDef).getBytes(StandardCharsets.UTF_8));
        } catch (ClassNotFoundException e) {
            throw new IOException(e);
        }
    }

    @Override
    protected void cacheFile(@NonNull Node<?> src, @NonNull File sink) throws IOException {
        ClassDef classDef = (ClassDef) src.getObject();
        if (classDef == null) {
            throw new FileNotFoundException("Class definition for " + src.getFullPath() + " is not found.");
        }
        try (FileOutputStream os = new FileOutputStream(sink)) {
            os.write(getDexClasses().getClassContents(classDef).getBytes(StandardCharsets.UTF_8));
        } catch (ClassNotFoundException e) {
            throw new IOException(e);

View on GitHub (pinned to 0152f468fc)

Solutions

  1. Confirm the class exists in the DEX (list nodes under the DEX mount) and use the exact full path.
  2. Remount the DEX filesystem so fresh ClassDef objects are built for each node.
  3. Catch FileNotFoundException and handle 'class not present in this DEX' explicitly.
  4. Avoid opening streams on non-class nodes of the DEX mount.

Example fix

// before
InputStream in = node.openInputStream();
// after
if (node.getObject() == null) throw new FileNotFoundException("Not a class in this DEX: " + node.getFullPath());
InputStream in = node.openInputStream();
Defensive patterns

Strategy: validation

Validate before calling

if (node.getObject() == null) throw new FileNotFoundException("Not a class in this DEX: " + node.getFullPath());

Type guard

static boolean isClassNode(Node<?> n) { return n.getObject() instanceof ClassDef; }

Try / catch

try (InputStream in = vfs.newInputStream(path)) {
    // read
} catch (FileNotFoundException e) {
    // class absent from this DEX: handle/skip
}

Prevention

When it happens

Trigger: Opening an InputStream on a DEX-VFS node whose getObject() (ClassDef) is null: the class name/path is not in the DEX, the DEX was reloaded so the node is stale, or the node is a directory/metadata pseudo-entry.

Common situations: Requesting a class after the DEX was replaced (hot-patch/update) without remounting; probing paths like classes.dex/ tree entries that are not classes; typo in the fully-qualified class path.

Understand the failure class

Background: "File not found" and ENOENT errors: why libraries can't find a file that should exist — this error's family across 50 libraries.

Related errors

AI-assisted analysis of MuntashirAkon/AppManager@0152f468fc (2026-09-12). Data as JSON: /api/errors/77003d854418532c. Report an issue: GitHub.