import java.io.File;

/**

 * 遍历文件夹

 */

public class ScannerFile {

    public static void main(String[] args) {

        // 1代表缩进，以便更好的显示

        printFiles(new File("E:\\eclipse32_workspace\\test"),1);

    }

    public static void printFiles(File dir,int tab){

        // 判断是否是文件夹

        if(dir.isDirectory()){

            // 将文件夹下的文件存入next

            File[] next = dir.listFiles();

            for(File file : next){

                // 分级显示

                for(int i = 0 ; i<tab-1;i++){

                    System.out.print("|--");

                }

                System.out.println(file.getName());

                // 嵌套显示

                if(file.isDirectory()){

                    printFiles(file,tab+1);

                }

            }

        }

    }

}

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) {

        // 文件读取

        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();

            }

        }

        // 文件写入（具有覆盖性）

        File newFile = new File("newtest.txt");

        try {

            FileOutputStream fos = new FileOutputStream(newFile);

            OutputStreamWriter osw = new OutputStreamWriter(fos, "UTF-8");

            BufferedWriter bw = new BufferedWriter(osw);

            bw.write("长歌行 汉乐府");

            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");

            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();

        }

    }

}