FilenameUtils

public static void main(String[] args) {
    String str = "group1/M00/01/25/wKgAvl4QDf-AdbR6AACRYiVw7CE045.jpg";
    String fullPath = FilenameUtils.getFullPath(str);
    String baseName = FilenameUtils.getBaseName(str);
    String extension = FilenameUtils.getExtension(str);
    System.out.println("文件夾名:"+fullPath);  // group1/M00/01/25/
    System.out.println("文件名："+baseName); // wKgAvl4QDf-AdbR6AACRYiVw7CE045
    System.out.println("文件後綴名:"+extension); // jpg

}