자바의 신 ch.26

package e.io.practice;


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

public class FileSizeSummary {
  public static void main(String[] args) {
    FileSizeSummary sample = new FileSizeSummary();
    String path = "C:\\godofjava";
    long sum = sample.printFileSize(path);
    System.out.println(path+"'s total size= " + sample.convertFileLength(sum));
  }

  public long printFileSize(String dirName) {
    File file = new File(dirName);
    long sum=0;
    if(file.isDirectory()) {
      File[] fileList = file.listFiles();
      for(File files : fileList) {
        if(files.isFile()) {
          String tempFileName = files.getAbsolutePath();
          long fileLength = files.length();

          sum += fileLength;
        } else {
          String tempDirName = files.getAbsolutePath();
          long fileLength = printFileSize(tempDirName);
          System.out.println("["+tempDirName+"]= "+convertFileLength(fileLength));
          sum+=fileLength;
        }

      }
    } return sum;
  }
  private String convertFileLength(long fileLength) {
    DecimalFormat decimal = new DecimalFormat("####.##");
    String size;
    if(fileLength <=1024) {
      size = decimal.format(fileLength) +" b";
    } else if(fileLength<=(1024*1024)) {
      size = decimal.format(1.0 * fileLength / 1024) +" kb";
    } else if(fileLength <= (1024*1024*1024)) {
      size = decimal.format(1.0 * fileLength / (1024 * 1024)) +" mb";
    } else {
      size = decimal.format(1.0 * fileLength / (1024 * 1024 * 1024)) +" gb";
    }
    return size;
  }
}