java 给一个借口对象,得到全部实现类对象的方法！

public static List<Class> getAllClassByInterface(Class c){
List<Class> returnClassList = new ArrayList<Class>();  // 
  if(c.isInterface()){
  String packageName = c.getPackage().getName();  //
   try {
   List<Class>  allClass = getClasses(packageName);  //
   
    //
    for(int i=0;i<allClass.size();i++){
     if(c.isAssignableFrom(allClass.get(i))){  //
      if(!c.equals(allClass.get(i))){   //
      returnClassList.add(allClass.get(i));
     }     
    }
   }
  } catch (ClassNotFoundException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  }
  }
   return returnClassList;
} 

private static List<Class> getClasses(String packageName)
   throws ClassNotFoundException, IOException {
ClassLoader classLoader = Thread.currentThread()
   .getContextClassLoader();
String path = packageName.replace('.', '/');
Enumeration<URL> resources = classLoader.getResources(path);
List<File> dirs = new ArrayList<File>();
  while (resources.hasMoreElements()) {
  URL resource = resources.nextElement();
  dirs.add(new File(resource.getFile()));
}
ArrayList<Class> classes = new ArrayList<Class>();
  for (File directory : dirs) {
  classes.addAll(findClasses(directory, packageName));
}
  return classes;
}

  private static List<Class> findClasses(File directory, String packageName)
throws ClassNotFoundException {
        List<Class> classes = new ArrayList<Class>();
        if (!directory.exists()) {
            return classes;
        }
        File[] files = directory.listFiles();
        for (File file : files) {
            if (file.isDirectory()) {
                assert !file.getName().contains(".");
                classes.addAll(findClasses(file, packageName + "." +
file.getName()));
            } else if (file.getName().endsWith(".class")) {
            classes.add(Class.forName(packageName+ '.' +
            file.getName().substring(0, file.getName().length() - 6)));
   }
        }
        return classes;
    }