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：

import java.io.File;
 
public class Scaner {
 
    public static void main(String[] args) {
        printFiles(new File("E:\\practice\\ReadFileProperty"), 1);
    }
    public static void printFiles(File dir,int tab) {
        if(dir.isDirectory()) {
            File next[]=dir.listFiles();
            for (int i = 0; i < next.length; i++) {
                for (int j = 0; j < tab; j++) {
                    System.out.print("|--");
                }
                System.out.println(next[i].getName());
                if(next[i].isDirectory()) {
                    printFiles(next[i], tab+1);
                }
            }
        }
    }
}

文件的读写操作：

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
 
public class readFile {
 
    public static void main(String[] args) {
        File file=new File("test.txt");
        if(file.exists()) {
            System.out.println("文件存在");
             
            try {
                FileInputStream fis=new FileInputStream(file);
                InputStreamReader isr=new InputStreamReader(fis,"UTF-8");
                BufferedReader br=new BufferedReader(isr);
                  
                String line;
                while((line=br.readLine())!=null) {
                    System.out.println(line);
                }
                br.close();
                isr.close();
                fis.close();
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        try {
            File newFile=new File("newText.txt");
            FileOutputStream fos=new FileOutputStream(newFile);
            OutputStreamWriter osw=new OutputStreamWriter(fos,"UTF-8");
            BufferedWriter bw=new BufferedWriter(osw);
             
            bw.write("长歌行\n");
            bw.write("青青园中葵，朝露待日晞。\n");
            bw.write("阳春布德泽，万物生光辉。\n");
            bw.write("常恐秋节至，焜黄华叶衰。\n");
            bw.write("百川东到海，何时复西归? \n");
            bw.write("少壮不努力，老大徒伤悲。\n");
             
            bw.close();
            osw.close();
            fos.close();
             
            System.out.println("写入完成");
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
 
}

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。