List<String> getClassPath() ; 获取 classpath 下所有的 类信息

可以使用以下代码获取 classpath 下的所有类信息：

List<String> classNames = new ArrayList<>();
ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
String classPath = System.getProperty("java.class.path");
String[] classPathEntries = classPath.split(System.getProperty("path.separator"));
for (String classPathEntry : classPathEntries) {
    File classFile = new File(classPathEntry);
    if (!classFile.exists()) {
        continue;
    }
    if (classFile.isDirectory()) {
        String[] classFiles = classFile.list((dir, name) -> name.endsWith(".class"));
        if (classFiles == null) {
            continue;
        }
        for (String classFileName : classFiles) {
            classNames.add(classFileName.substring(0, classFileName.length() - 6));
        }
    } else {
        try (JarFile jarFile = new JarFile(classFile)) {
            Enumeration<JarEntry> entries = jarFile.entries();
            while (entries.hasMoreElements()) {
                JarEntry jarEntry = entries.nextElement();
                String jarEntryName = jarEntry.getName();
                if (!jarEntryName.endsWith(".class")) {
                    continue;
                }
                String className = jarEntryName.substring(0, jarEntryName.lastIndexOf(".")).replace("/", ".");
                classNames.add(className);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}