java 获取文件夹大小，文件大小，文件个数

import java.io.File;
import java.text.DecimalFormat;
import java.io.FileInputStream;

public class GetFileSize
{
public long getFileSizes(File f) throws Exception{//取得文件大小
long s=0;
if (f.exists()) {
FileInputStream fis = null;
fis = new FileInputStream(f);
s= fis.available();
} else {
f.createNewFile();
System.out.println("文件不存在");
}
return s;
}
// 递归
public long getFileSize(File f)throws Exception//取得文件夹大小
{
long size = 0;
File flist[] = f.listFiles();
for (int i = 0; i < flist.length; i++)
{
if (flist[i].isDirectory())
{
size = size + getFileSize(flist[i]);
} else
{
size = size + flist[i].length();
}
}
return size;
}

public String FormetFileSize(long fileS) {//转换文件大小
DecimalFormat df = new DecimalFormat("#.00");
String fileSizeString = "";
if (fileS < 1024) {
fileSizeString = df.format((double) fileS) + "B";
} else if (fileS < 1048576) {
fileSizeString = df.format((double) fileS / 1024) + "K";
} else if (fileS < 1073741824) {
fileSizeString = df.format((double) fileS / 1048576) + "M";
} else {
fileSizeString = df.format((double) fileS / 1073741824) + "G";
}
return fileSizeString;
}

public long getlist(File f){//递归求取目录文件个数
long size = 0;
File flist[] = f.listFiles();
size=flist.length;
for (int i = 0; i < flist.length; i++) {
if (flist[i].isDirectory()) {
size = size + getlist(flist[i]);
size--;
}
}
return size;

}

public static void main(String args[])
{
GetFileSize g = new GetFileSize();
long startTime = System.currentTimeMillis();
try
{
long l = 0;
String path = "C://WINDOWS";
File ff = new File(path);
if (ff.isDirectory()) { //如果路径是文件夹的时候
System.out.println("文件个数 " + g.getlist(ff));
System.out.println("目录");
l = g.getFileSize(ff);
System.out.println(path + "目录的大小为：" + g.FormetFileSize(l));
} else {
System.out.println(" 文件个数 1");
System.out.println("文件");
l = g.getFileSizes(ff);
System.out.println(path + "文件的大小为：" + g.FormetFileSize(l));
}

} catch (Exception e)
{
e.printStackTrace();
}
long endTime = System.currentTimeMillis();
System.out.println("总共花费时间为：" + (endTime - startTime) + "毫秒...");
}
}