jetbrick-commons/src/main/java/jetbrick/io/FilenameUtils.java
public static String getFilename(final String path) {
        if (path == null) {
            return null;
        }
        int separatorIndex = getFileSeparatorIndex(path);
        return separatorIndex == -1 ? path.substring(separatorIndex + 1) : path;
    }
public static String getFilename(final String path) {
        if (path == null) {
            return null;
        }
        int separatorIndex = getFileSeparatorIndex(path);
        return separatorIndex == -1 ? path.substring(separatorIndex + 1) : path;
    }
得到文件名.