java对文件名的几个操作，获取文件扩展名，去掉扩展名

** * Return the extension portion of the file’s name . * * @see #getExtension */ public static String getExtension(File f) { return (f != null) ? getExtension(f.getName()) : “”; }

public static String getExtension(String filename) { return getExtension(filename, “”); }

public static String getExtension(String filename) { return getExtension(filename, “”); }

public static String getExtension(String filename, String defExt) { if ((filename != null) && (filename.length() > 0)) { int i = filename.lastIndexOf(‘.’);

if ((i >-1) && (i < (filename.length() – 1))) { return filename.substring(i + 1); } } return defExt; }

public static String trimExtension(String filename) { if ((filename != null) && (filename.length() > 0)) { int i = filename.lastIndexOf(‘.’); if ((i >-1) && (i < (filename.length()))) { return filename.substring(0, i); } } return filename; }

也许叔本华是对的，人与人的距离太远会寂寞到寒冷，