Flink-如何在flink sinkfunction中查找java包下的所有类

Question

如何在flink sinkfunction中查找java包下的所有类？在 SinkFunction 中运行这些代码时我什么也没得到。请参阅以下代码

public Set<Class> findAllClassesUsingClassLoader(String packageName) {
    InputStream stream = ClassLoader.getSystemClassLoader()
      .getResourceAsStream(packageName.replaceAll("[.]", "/"));
    BufferedReader reader = new BufferedReader(new InputStreamReader(stream));
    return reader.lines()
      .filter(line -> line.endsWith(".class"))
      .map(line -> getClass(line, packageName))
      .collect(Collectors.toSet());
}

private Class getClass(String className, String packageName) {
    try {
        return Class.forName(packageName + "."
          + className.substring(0, className.lastIndexOf('.')));
    } catch (ClassNotFoundException e) {
        // handle the exception
    }
    return null;
}