Konloch/bytecode-viewer · error · LoaderException

'${file.getAbsolutePath()}' not found.

Error message

'${file.getAbsolutePath()}'  not found.

What it means

DirectoryLoader.load() wraps any IOException from opening/reading the requested .class file on disk into a LoaderException whose message is the resolved absolute path plus 'not found.' It is thrown whenever FileInputStream construction or stream reading fails for the codebase+internalPath combination, whether the file truly does not exist or is unreadable (permission, directory, I/O error). The library conflates all IOExceptions into a single 'not found' message.

Source

Thrown at src/main/java/the/bytecode/club/bytecodeviewer/decompilers/jdgui/DirectoryLoader.java:60

        if (!(file.exists() && file.isDirectory()))
            throw new LoaderException("'" + codebase + "' is not a directory");
    }

    @Override
    public byte[] load(String internalPath) throws LoaderException
    {
        if (!internalPath.endsWith(".class"))
            internalPath = internalPath + ".class";

        File file = new File(this.codebase, internalPath);

        try (FileInputStream fis = new FileInputStream(file); BufferedInputStream bis = new BufferedInputStream(fis))
        {
            return IOUtils.toByteArray(bis);
        }
        catch (IOException e)
        {
            throw new LoaderException("'" + file.getAbsolutePath() + "'  not found.");
        }
    }

    @Override
    public boolean canLoad(String internalPath)
    {
        File file = new File(this.codebase, internalPath + ".class");
        return file.exists() && file.isFile();
    }
}

View on GitHub (pinned to 31430e0033)

Solutions

1. Verify the file exists and is readable at the exact path printed in the message before calling load(): new File(codebase, path.endsWith(".class") ? path : path + ".class").exists().
2. Check package separators: internalPath must use '/' internally; the loader appends '.class' if absent, so do not pre-append '.class' twice or pass OS separators.
3. Rebuild/restore the class directory or re-point the DirectoryLoader constructor at a directory that actually contains the compiled classes (constructor already validates it is a directory).
4. Fix filesystem permissions (chmod/chown) if the path exists but the JVM cannot read it; note permission failures also surface as this 'not found.' message.
5. Catch LoaderException per-file in your caller and skip/log the class rather than aborting the whole decompilation run.

Example fix

// before
byte[] bytes = loader.load("com/example/Missing.class");

// after
if (loader.canLoad("com/example/Missing")) {
    byte[] bytes = loader.load("com/example/Missing.class");
} else {
    // handle missing class: skip, log, or load from another loader
}

File f = new File(codebase, internalPath.endsWith(".class") ? internalPath : internalPath + ".class");
if (!f.exists() || !f.isFile()) throw new IllegalStateException("Class file missing: " + f.getAbsolutePath());

static boolean classFileExists(String codebase, String internalPath) {
    String p = internalPath.endsWith(".class") ? internalPath : internalPath + ".class";
    File f = new File(codebase, p);
    return f.isFile();
}

try {
    byte[] bytes = loader.load(internalPath);
} catch (org.jd.core.v1.api.loader.LoaderException e) {
    logger.warn("Class not loadable: {}", e.getMessage());
    // fallback: skip class or load from alternate loader
}

When it happens

Trigger: Calling load(internalPath) (directly or via jd.core decompilation of a directory-based codebase) where codebase/internalPath (with .class appended if missing) does not exist, is a directory, lacks read permission, or an I/O error occurs while reading.

Common situations: Passing an internal path with the wrong package separators or a stale class name after refactoring; pointing the DirectoryLoader at an output directory that was cleaned while decompilation is in flight; files filtered out by obfuscation tools; OS permission issues; symlinks broken after moving the directory.

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

• Unable to resolve class-filetype.
• Unable to resolve type.
• Invalid Java .class file
• Unknown Java structure
• Invalid constant pool

AI-assisted analysis of Konloch/bytecode-viewer@31430e0033 (2026-09-05). Data as JSON: /api/errors/e7a619ffb94337e7. Report an issue: GitHub.