import java.io.File;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.List;

public class FileViewer {

	public static List<String> getListFiles(String path, String suffix,
			boolean isdepth) {
		List<String> lstFileNames = new ArrayList<String>();
		File file = new File(path);
		return FileViewer.listFile(lstFileNames, file, suffix, isdepth);
	}

	private static List<String> listFile(List<String> lstFileNames, File f,
			String suffix, boolean isdepth) {
		// 若是目录, 采用递归的方法遍历子目录
		if (f.isDirectory()) {
			File[] t = f.listFiles();

			for (int i = 0; i < t.length; i++) {
				if (isdepth || t[i].isFile()) {
					listFile(lstFileNames, t[i], suffix, isdepth);
				}
			}
		} else {
			String filePath = f.getAbsolutePath();
			if (!suffix.equals("")) {
				int begIndex = filePath.lastIndexOf("."); // 最后一个.(即后缀名前面的.)的索引
				String tempsuffix = "";

				if (begIndex != -1) {
					tempsuffix = filePath.substring(begIndex + 1,
							filePath.length());
					if (tempsuffix.equals(suffix)) {
						lstFileNames.add(filePath);
					}
				}
			} else {
				lstFileNames.add(filePath);
			}
		}
		return lstFileNames;
	}

	// 递归取得文件夹（包括子目录）中所有文件的大小
	public static 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 static 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 static void main(String[] args) {
		File file = new File("D:\\tools");
		List<String> list = getListFiles("D:\\tools", "", true);
		for (String fileName : list) {
			System.out.println(fileName);
		}
		System.out.println(list.size());
		try {
			System.out.println(FormetFileSize(getFileSize(file)));
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}