一个常用的Java文件操作类FileUtil.java源代码，类中的所有方法都是静态方法，不需要生成此类的实例，这些Java文件操作类主要有修改文件的最后访问时间、判断指定的文件是否存在、创建指定的目录、清空指定目录中的文件、删除指定目录及其中的所有内容、列出目录中的所有内容，包括其子目录中、将目录中的内容添加到列表、返回文件的URL地址、从文件路径得到文件名、将DOS/Windows格式的路径转换为UNIX/Linux格式的路径、得到文件类型和文件名、得到路径分隔符在文件路径中指定位置后首次出现的位置、将文件名中的类型部分去掉、得到相对路径、检查给定目录的存在性、读取文件的内容、获取图片文件的扩展名、计算图片数量-A common file operations class FileUtil.java Java source code, class all the methods are static methods need to generate instances of this class, the Java class file operations are mainly modified the file last access time to determine whether the specified file exist, create the specified directory, empty files in the specified directory, delete the specified directory and all contents, list all the contents of the directory, including subdirectories, add the contents of the directory to the list, returns the file s URL address, to get the file name from the file path, the path of DOS/Windows format into the path UNIX/Linux format to get the file type and file name, to get the position after the first path separator specified location in the file path, file type the name of the part removed, get a relative path, check the existence of a given directory, read the contents of the file, get the picture file extensions, calculate the number of images, etc.