Java 遍历文件夹,文件读写
遍历文件夹,输出文件夹下的所有文件和文件名:
1 import java.io.File; 2 3 public class Scaner { 4 5 public static void main(String[] args) { 6 printFiles(new File("E:\\practice\\ReadFileProperty"), 1); 7 } 8 public static void printFiles(File dir,int tab) { 9 if(dir.isDirectory()) { 10 File next[]=dir.listFiles(); 11 for (int i = 0; i < next.length; i++) { 12 for (int j = 0; j < tab; j++) { 13 System.out.print("|--"); 14 } 15 System.out.println(next[i].getName()); 16 if(next[i].isDirectory()) { 17 printFiles(next[i], tab+1); 18 } 19 } 20 } 21 } 22 }
文件的读写操作:
1 import java.io.BufferedReader; 2 import java.io.BufferedWriter; 3 import java.io.File; 4 import java.io.FileInputStream; 5 import java.io.FileNotFoundException; 6 import java.io.FileOutputStream; 7 import java.io.IOException; 8 import java.io.InputStreamReader; 9 import java.io.OutputStreamWriter; 10 import java.io.UnsupportedEncodingException; 11 12 public class readFile { 13 14 public static void main(String[] args) { 15 File file=new File("test.txt"); 16 if(file.exists()) { 17 System.out.println("文件存在"); 18 19 try { 20 FileInputStream fis=new FileInputStream(file); 21 InputStreamReader isr=new InputStreamReader(fis,"UTF-8"); 22 BufferedReader br=new BufferedReader(isr); 23 24 String line; 25 while((line=br.readLine())!=null) { 26 System.out.println(line); 27 } 28 br.close(); 29 isr.close(); 30 fis.close(); 31 } catch (FileNotFoundException e) { 32 e.printStackTrace(); 33 } catch (UnsupportedEncodingException e) { 34 e.printStackTrace(); 35 } catch (IOException e) { 36 e.printStackTrace(); 37 } 38 } 39 try { 40 File newFile=new File("newText.txt"); 41 FileOutputStream fos=new FileOutputStream(newFile); 42 OutputStreamWriter osw=new OutputStreamWriter(fos,"UTF-8"); 43 BufferedWriter bw=new BufferedWriter(osw); 44 45 bw.write("长歌行\n"); 46 bw.write("青青园中葵,朝露待日晞。\n"); 47 bw.write("阳春布德泽,万物生光辉。\n"); 48 bw.write("常恐秋节至,焜黄华叶衰。\n"); 49 bw.write("百川东到海,何时复西归? \n"); 50 bw.write("少壮不努力,老大徒伤悲。\n"); 51 52 bw.close(); 53 osw.close(); 54 fos.close(); 55 56 System.out.println("写入完成"); 57 } catch (FileNotFoundException e) { 58 e.printStackTrace(); 59 } catch (UnsupportedEncodingException e) { 60 e.printStackTrace(); 61 } catch (IOException e) { 62 e.printStackTrace(); 63 } 64 } 65 66 }
程序输出文件test.txt中的内容,并且把内容写入到新文件newText.txt中。