java file 获取文件大小 返回 xx BT xx KB xx MB

public static String GetFileSize(String Path){

return GetFileSize(new File(Path));

}

public static String GetFileSize(File file){

String size = "";

if(file.exists() && file.isFile()){

long fileS = file.length();

DecimalFormat df = new DecimalFormat("#.00");

if (fileS < 1024) {

size = df.format((double) fileS) + "BT";

} else if (fileS < 1048576) {

size = df.format((double) fileS / 1024) + "KB";

} else if (fileS < 1073741824) {

size = df.format((double) fileS / 1048576) + "MB";

} else {

size = df.format((double) fileS / 1073741824) +"GB";

}

}else if(file.exists() && file.isDirectory()){

size = "";

}else{

size = "0BT";

}

return size;

}