private static List<Class<?>> getClassesInDirectory(
File directory, String packageName, ClassLoader classLoader)
throws UnsupportedEncodingException {
List<Class<?>> classes = new ArrayList<Class<?>>();
// Capture all the .class files in this directory
// Get the list of the files contained in the package
String[] files = directory.list();
for (String currentFile : files) {
// we are only interested in .class files
if (currentFile.endsWith(".class")) {
// removes the .class extension
// CHECKSTYLE:OFF
try {
classes.add(
Class.forName(
packageName + '.' + currentFile.substring(0, currentFile.length() - 6)));
} catch (Throwable e) {
// do nothing. this class hasn't been found by the loader, and we don't care.
}
// CHECKSTYLE:ON
} else {
// It's another package
String subPackageName = packageName + '.' + currentFile;
// Ask for all resources for the path
URL resource = classLoader.getResource(subPackageName.replace('.', '/'));
File subDirectory = new File(URLDecoder.decode(resource.getPath(), "UTF-8"));
List<Class<?>> classesForSubPackage =
getClassesInDirectory(subDirectory, subPackageName, classLoader);
classes.addAll(classesForSubPackage);
}
}
return classes;
}
/**
* Retrieves recursively all the classes belonging to a package.
*
* @param packageName
* @param classLoader the class loader used to load the class in the given package
* @return the list of Class found
* @throws ClassNotFoundException if any error occurs
*/
public static List<Class<?>> getClassesInPackage(String packageName, ClassLoader classLoader)
throws ClassNotFoundException {
try {
if (classLoader == null) {
throw new ClassNotFoundException("Can't get class loader.");
}
String path = packageName.replace('.', '/');
// Ask for all resources for the path
Enumeration<URL> resources = classLoader.getResources(path);
List<Class<?>> classes = new ArrayList<Class<?>>();
while (resources.hasMoreElements()) {
URL resource = resources.nextElement();
File directory = new File(URLDecoder.decode(resource.getPath(), "UTF-8"));
if (directory.canRead()) {
classes.addAll(getClassesInDirectory(directory, packageName, classLoader));
} else {
// it's a jar file
classes.addAll(
getClassesInJarFile(
directory.getPath().substring(5, directory.getPath().indexOf(".jar") + 4),
packageName));
}
}
return classes;
} catch (NullPointerException x) {
throw new ClassNotFoundException(
packageName + " does not appear to be a valid package (Null pointer exception)", x);
} catch (UnsupportedEncodingException encex) {
throw new ClassNotFoundException(
packageName + " does not appear to be a valid package (Unsupported encoding)", encex);
} catch (IOException ioex) {
throw new ClassNotFoundException(
"IOException was thrown when trying to get all resources for " + packageName, ioex);
}
}