文件读写并处理FileNotFoundException异常

package lianxi;

 

import java.io.BufferedReader;

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.PrintWriter;

import java.util.Scanner;

/**

 * 读写文件，处理FileNotFoundException异常

 * @author xiaoyu

 *

 */

public class ReadWriterFile {

    public static void main(String[] args)throws Exception {

        ReadWriterFile rwf = new ReadWriterFile();

        rwf.readFile();

        rwf.writeFile();

    }

    public void readFile()throws IOException {

        Scanner scanner = new Scanner(System.in);

        System.out.println("请输入要读取的文件名:");

        String name = scanner.nextLine();

        BufferedReader br = null;

        while(br == null) {

            try {

                br = new BufferedReader(

                        new InputStreamReader(

                                new FileInputStream(name)));

            } catch (FileNotFoundException e) {

                System.out.println(br);

                System.out.println("读取文件错误，请重新输入:");

                name = scanner.nextLine();

            }  

        }

        System.out.println("读取文件成功!");

        while(true) {

                String line = br.readLine();

                if(line == null) {

                    break;

                }

                System.out.println(line);

        }

        br.close();

    }

     

    public void writeFile()throws IOException {

        Scanner scanner = new Scanner(System.in);

        System.out.println("请输入文件名:");

        PrintWriter pw = null;

        String name;

        while(pw == null) {

            try {

                name = scanner.nextLine();

                pw = new PrintWriter(

                        new OutputStreamWriter(

                                new FileOutputStream(name,true)));

                //true表示追加，没有表示覆盖原文件！

            } catch (FileNotFoundException e) {

                e.printStackTrace();

                System.out.println("文件格式错误，请重新输入：");

                name = scanner.nextLine();

                pw = null;

            }

        }

        System.out.println("创建或读取文件成功!");

        pw.write("don't worry,");

        pw.write("be happy!");

        pw.flush();

        pw.close();

    }

}