处理流——缓冲流

抽象基类	节点流（文件流）	缓冲流
InputStream（字节流）	FileInputStream	BufferedInputStream
OutputStream（字节流）	FileOutputStream	BufferedOutputStream
Reader（字符流）	FileReader	BufferedReader
Writer（字符流）	FileWriter	BufferedWriter

 

 

 

 

 

 

 

@Test

    public void testBufferedReader() throws Exception {

        File f1 = new File("hello3.txt");

        FileReader fr = new FileReader(f1);

        File f2 = new File("hello5.txt");

        FileWriter fw = new FileWriter(f2);

        BufferedReader br = new BufferedReader(fr);

        BufferedWriter bw = new BufferedWriter(fw);

// int len;

// char[] c = new char[100];

// while((len=br.read(c)) != -1){

// String str = new String(c,o,len);

// System.out.println(str);

// }

        String str = "";

        while ((str = br.readLine()) != null) {

            bw.write(str);

            bw.newLine();

            bw.flush();

        }

        bw.close();

        br.close();

        fw.close();

        fr.close();

    }

//使用缓冲流的拷贝文件封装的方法

// @Test

// public void copyFile(String src,String desc) throws Exception{

// long ct1= System.currentTimeMillis();

// File file = new File(src);

// File file2 = new File(desc);

// FileInputStream fis = new FileInputStream(file);

// FileOutputStream fos = new FileOutputStream(file2);

// BufferedInputStream bis = new BufferedInputStream(fis);

// BufferedOutputStream bos = new BufferedOutputStream(fos);

// int len;

// byte[] b = new byte[1024];

// while((len = (bis.read(b))) != -1){

// bos.write(b, 0, len);

// }

// long ct2 = System.currentTimeMillis();

// long time = ct2-ct1;

// System.out.println(time);

// bos.close();

// bis.close();

// fos.close();

// fis.close();

// }

//使用BufferedInputOutputStream实现非文本文件的复制

    @Test

    public void BufferedInputOutputStream() throws Exception {

        long ct1 = System.currentTimeMillis();

        File file = new File("/Users/lixiuming/Desktop/商品详情图片/detail-1.jpg");

        File file2 = new File("/Users/lixiuming/Desktop/project/day_15/detail-3.jpg");

        FileInputStream fis = new FileInputStream(file);

        FileOutputStream fos = new FileOutputStream(file2);

        BufferedInputStream bis = new BufferedInputStream(fis);

        BufferedOutputStream bos = new BufferedOutputStream(fos);

        int len;

        byte[] b = new byte[1024];

        while ((len = (bis.read(b))) != -1) {

            bos.write(b, 0, len);

            bos.flush();// 缓冲流独有的东西

        }

        long ct2 = System.currentTimeMillis();

        long time = ct2 - ct1;

        System.out.println(time);

        bos.close();

        bis.close();

        fos.close();

        fis.close();

    }

 

缓冲流属于处理流，包在节节点流外面