博客

1.用来判断文件大小的方法的类
package com.email.filesize;

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

public class GetFileSize {

	public GetFileSize() {

	}

	public long getFileSizes(File f) throws Exception {

		long s = 0;
		if (f.exists()) {
			FileInputStream fis = null;
			fis = new FileInputStream(f);
			s = fis.available();
			fis.close();
		} else {
			f.createNewFile();
			System.out.println("文件夹不存在");
		}

		return s;
	}

	/**
	 * 递归
	 * */
	public long getFileSize(File f) {
		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;
	}

	/**
	 * 转换文件大小
	 * */
	public String FormentFileSize(long fileS) {
		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;
	}

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

}

2.判断文件大小，在主函数中写的语句
GetFileSize g = new GetFileSize();
String path = File.separator + "mnt" + File.separator + "sdcard" + File.separator + "1.txt";
File ff = new File(path);
try {
       l = g.getFileSizes(ff);
    } catch (Exception e) {
      e.printStackTrace();
    }
 System.out.println(path + "文件的大小为：" + g.FormentFileSize(l));