Java File IO 练习题：把一个文件夹下的.java文件复制到另一个文件夹下的.txt文件

package com.swift;

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 Copy_java_To_txt {

    public static void main(String[] args) {
        /*
         * 把一个文件夹下的.java文件复制到另一个文件夹下的.txt文件
         */
        try {
            StringBuffer sb = new StringBuffer();
            BufferedReader br = new BufferedReader(
                    new InputStreamReader(new FileInputStream("e:\\neck\\test.java"), "utf-8"));
            String str;
            while ((str = br.readLine()) != null) {
                System.out.println("从文件中读取了一行...");
                sb.append(str);
                sb.append("\r\n");
            }
            
            System.out.println("文件读取到容器成功"+"\r\n"+sb.toString());
            
            String dir="e:\\apple";
            String fileName="test.txt";
            File file=new File(dir,fileName);
            if(!file.getParentFile().exists()) {
                System.out.println(file.getParentFile()+"目录不存在，即将创建...");
                file.getParentFile().mkdirs();
            }else {
                System.out.println("目录存在，不用创建...");
            }
            BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file),"utf-8"));
            bw.write(sb.toString());
            bw.flush();

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}