skylot/jadx · error · JadxRuntimeException

Package is null for not inner class

Error message

Package is null for not inner class

What it means

Thrown by ClassInfo.getPackage() when the class is not inner (parentClass == null) but its pkg field is null. A top-level class must have a package string (possibly empty for the default package); a null package on a top-level class is an invariant violation, usually a partially-constructed or corrupted ClassInfo.

Source

Thrown at jadx-core/src/main/java/jadx/core/dex/info/ClassInfo.java:239

		}
		return aliasPkg.replace('.', File.separatorChar) + File.separatorChar + fileName;
	}

	public String getFullName() {
		return fullName;
	}

	public String getShortName() {
		return name;
	}

	@NotNull
	public String getPackage() {
		if (parentClass != null) {
			return parentClass.getPackage();
		}
		if (pkg == null) {
			throw new JadxRuntimeException("Package is null for not inner class");
		}
		return pkg;
	}

	public boolean isDefaultPackage() {
		return getPackage().isEmpty();
	}

	public String getRawName() {
		return type.getObject();
	}

	public String getAliasNameWithoutPackage() {
		if (parentClass == null) {
			return getAliasShortName();
		}
		return parentClass.getAliasNameWithoutPackage() + '.' + getAliasShortName();
	}

View on GitHub (pinned to e738a26571)

Solutions

1. Always build ClassInfo via the factory methods (fromName/fromType) which initialise pkg.
2. If constructing manually, ensure pkg is set to "" (default package) at minimum, never null.
3. Audit code paths that mutate pkg to confirm none can set it to null on a top-level class.
4. Defensively, treat null pkg as the default package instead of throwing.

Example fix

// before
if (pkg == null) {
    throw new JadxRuntimeException("Package is null for not inner class");
}
return pkg;

// after (treat null as default package)
if (pkg == null) {
    LOG.warn("Null package on top-level class {}", this);
    return "";
}
return pkg;

// Ensure pkg is non-null at construction for top-level classes
String pkg = computedPkg != null ? computedPkg : "";

static boolean hasValidPackage(ClassInfo ci) {
    return ci.isInner() || ci.getPackageField() != null;
}

String pkg;
try {
    pkg = classInfo.getPackage();
} catch (JadxRuntimeException e) {
    pkg = ""; // default package fallback
}

When it happens

Trigger: A top-level ClassInfo constructed without initialising the package; reflection/deserialisation that left pkg null; a ClassInfo built from a malformed class name that yielded no package; mutation paths that set pkg to null.

Common situations: Corrupt class descriptors; ClassInfo objects built outside the normal factory (fromName/fromType); partial copies; bugs in alias logic that null out pkg.

Related errors

• Null class type
• Unexpected key in switch:
• Unexpected arg type in catch block:
• Unknown type in literalToString:
• Unexpected visibility flag:

AI-assisted analysis of skylot/jadx@e738a26571 (2026-08-14). Data as JSON: /api/errors/a04d9b5aceebe268. Report an issue: GitHub.