/* * Copyright 2022 Anton Tananaev (anton@traccar.org) * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.traccar.helper; import java.io.File; import java.io.IOException; import java.net.URI; import java.net.URISyntaxException; import java.net.URL; import java.net.URLDecoder; import java.nio.charset.StandardCharsets; import java.util.Enumeration; import java.util.LinkedList; import java.util.List; import java.util.jar.JarEntry; import java.util.jar.JarFile; public final class ClassScanner { private ClassScanner() { } public static List<Class<?>> findSubclasses( Class<?> baseClass) throws IOException, URISyntaxException, ReflectiveOperationException { return findSubclasses(baseClass, baseClass.getPackageName()); } public static List<Class<?>> findSubclasses(Class<?> baseClass, String packageName) throws IOException, URISyntaxException, ReflectiveOperationException { List<String> names = new LinkedList<>(); String packagePath = packageName.replace('.', '/'); URL packageUrl = baseClass.getClassLoader().getResource(packagePath); if (packageUrl.getProtocol().equals("jar")) { String jarFileName = URLDecoder.decode(packageUrl.getFile(), StandardCharsets.UTF_8.name()); try (JarFile jf = new JarFile(jarFileName.substring(5, jarFileName.indexOf("!")))) { Enumeration<JarEntry> jarEntries = jf.entries(); while (jarEntries.hasMoreElements()) { String entryName = jarEntries.nextElement().getName(); if (entryName.startsWith(packagePath) && entryName.length() > packagePath.length() + 5) { names.add(entryName.substring(packagePath.length() + 1, entryName.lastIndexOf('.'))); } } } } else { File folder = new File(new URI(packageUrl.toString())); File[] files = folder.listFiles(); if (files != null) { for (File actual: files) { String entryName = actual.getName(); names.add(entryName.substring(0, entryName.lastIndexOf('.'))); } } } var classes = new LinkedList<Class<?>>(); for (String name : names) { var clazz = Class.forName(packageName + '.' + name); if (baseClass.isAssignableFrom(clazz)) { classes.add(clazz); } } return classes; } }