1、获取单个属性并已经知道该属性的名称
Object size = Files.getAttribute(Paths.get(dirAbsolutePath + "/" + filename), "size");
2、获取多个属性,对属性名称不太熟悉
BasicFileAttributeView fileAttributeView = Files.getFileAttributeView(Paths.get(dirAbsolutePath + "/" + filename), BasicFileAttributeView.class);
BasicFileAttributes basicFileAttributes = fileAttributeView.readAttributes();
long size = basicFileAttributes.size();