文件，目录的使用

import java.io.*;
public class TestFile {
public static void main(String[] args) {		String separator = File.separator;		String filename = "myfile.txt";		String directory = "mydir1"+separator+"mydir2";		File f = new File(directory,filename);		if(f.exists()){			System.out.println("文件名"+f.getAbsolutePath());			System.out.println("文件夹"+f.length());		}else{			f.getParentFile().mkdirs();			try{				f.createNewFile();			}catch(IOException e){				e.printStackTrace();			}		}	}
}