Java IO流读取文件的几种方式

1.InputStream：

public static void main(String[] args) {
        try {
            InputStream inputStream =new FileInputStream("E:/1.txt");
            OutputStream outputStream = new FileOutputStream("E:/kk/1.txt");
            int bytesRead = 0;
            byte[] buffer = new byte[8192];
            while ((bytesRead = inputStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, bytesRead);
            }
            inputStream.close();
        }catch (IOException e){
            e.printStackTrace();
        }
    }

2.FileInputStream

 public static void main(String[] args) {
        copeFile("C:/Users/liang/Pictures/Saved Pictures/lql.txt","D:/lql.txt");
    }
    public static void copeFile(String sourceFile,String targetFile){
        try {
            //实例化字节流
            FileInputStream fileInputStream = new FileInputStream(sourceFile);
            FileOutputStream fileOutputStream=new FileOutputStream(targetFile);
            //实例化处理流
            BufferedInputStream bf=new BufferedInputStream(fileInputStream);
            BufferedOutputStream bo=new BufferedOutputStream(fileOutputStream);
            byte [] buffer=new byte[1024];//字符数组缓冲区
           int temp=0;
           while ((temp=bf.read(buffer))!=-1){
               bo.write(buffer,0,temp);
           }
           
           bo.flush();

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

3.FileReader:字符缓冲流readLine()每次会读取文本中的一行数据

public static void main(String[] args) {
        try{
            FileReader fr=new FileReader("C:/Users/liang/Pictures/Saved Pictures/lql.txt");
            BufferedReader br=new BufferedReader(fr);
            String temp="";
            //readLine()：表示读取一行文本。
            while ((temp=br.readLine())!=null){
                System.out.println(temp);
            }
        }catch (IOException e){
            e.printStackTrace();
        }
    }