按行读取

fileInputStream是字节byte型
FileWriter 是字节char型

补充案例（按行读取）

        package com.IO;
 
        import java.io.*;
 
        public class Line {
            public static void main(String[] args) {
                File file = new File("D://IDEA/Demo.txt");
                File file1 = new File("D://IDEA/DemoCopy.txt");
                try {
                    FileReader fileInputStream = new FileReader(file);
                    FileWriter fileOutputStream =new FileWriter(file1);//FileWriter/字符char级fileInputStream是字节byte型
                    BufferedReader bufferedInput = new BufferedReader(fileInputStream);
                    BufferedWriter bufferedOutput = new BufferedWriter(fileOutputStream);
                    //创建缓存队列
                    /*
                    main:1
                    char []chars = new char[1024*6];
                    int read = bufferedInput.read(chars);
                    while (read!=-1){
                        bufferedOutput.write(chars,0,read);
                        read = bufferedInput.read(chars);
                    }*/
                    /*
                    main:按行读取
                    String str =bufferedInput.readLine();
                    while (str!=null){
                        bufferedOutput.write(str);
                        bufferedOutput.newLine();
                        str =bufferedInput.readLine();
                    }*/
                    bufferedOutput.close();
                    bufferedInput.close();
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }