container/common/src/main/java/org/mobicents/slee/container/deployment/ConcreteClassGeneratorUtils.java
static private void validateDirectory(File aDirectory)
			throws FileNotFoundException {
		if (aDirectory == null) {
			throw new IllegalArgumentException("Directory should not be null.");
		}
		if (!aDirectory.exists()) {
			throw new FileNotFoundException("Directory does not exist: "
					+ aDirectory);
		}
		if (!aDirectory.isDirectory()) {
			throw new IllegalArgumentException("Is not a directory: "
					+ aDirectory);
		}
		if (!aDirectory.canRead()) {
			throw new IllegalArgumentException("Directory cannot be read: "
					+ aDirectory);
		}
	}
static private void validateDirectory(File aDirectory)
			throws FileNotFoundException {
		if (aDirectory == null) {
			throw new IllegalArgumentException("Directory should not be null.");
		}
		if (!aDirectory.exists()) {
			throw new FileNotFoundException("Directory does not exist: "
					+ aDirectory);
		}
		if (!aDirectory.isDirectory()) {
			throw new IllegalArgumentException("Is not a directory: "
					+ aDirectory);
		}
		if (!aDirectory.canRead()) {
			throw new IllegalArgumentException("Directory cannot be read: "
					+ aDirectory);
		}
	}
Directory is valid if it exists, does not represent a file, and can be read.