Java中缓冲流的使用

• Java中缓冲流的使用
• • 一、功能
  • 二、示例
  • • （一）字节流
    • （二）字符流

内部提供了一个缓冲区，可以提高读写速度。

@Test
    public void bufferedInputStreamTest() {
        FileInputStream fileInputStream = null;
        FileOutputStream fileOutputStream = null;
        BufferedInputStream bufferedInputStream = null;
        BufferedOutputStream bufferedOutputStream = null;
        try {
            //1、造文件
            File srcFile = new File("hello.txt");
            File destFile = new File("hi.txt");
            //2、造节点流
            fileInputStream = new FileInputStream(srcFile);
            fileOutputStream = new FileOutputStream(destFile);
            //3、造缓冲流
            bufferedInputStream = new BufferedInputStream(fileInputStream);
            bufferedOutputStream = new BufferedOutputStream(fileOutputStream);

            //4、读取、写入
            byte[] buffer = new byte[10];
            int len;
            while ((len = bufferedInputStream.read(buffer)) != -1) {
                bufferedOutputStream.write(buffer, 0, len);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            //5、关闭流
            if (bufferedOutputStream != null) {
                try {
                    bufferedOutputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (bufferedInputStream != null) {
                try {
                    bufferedInputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            //关闭外层流的同时，内存流也会自动的进行关闭，关于内层流的关闭，可以省略。
            
        }
    }

@Test
    public void bufferedStreamTest() {
        FileReader fileReader = null;
        FileWriter fileWriter = null;
        BufferedReader bufferedReader = null;
        BufferedWriter bufferedWriter = null;
        try {
            //1、造文件
            File srcFile = new File("hello.txt");
            File destFile = new File("hi.txt");
            //2、造节点流
            fileReader = new FileReader(srcFile);
            fileWriter = new FileWriter(destFile);
            //3、造缓冲流
            bufferedReader = new BufferedReader(fileReader);
            bufferedWriter = new BufferedWriter(fileWriter);

            //4、读取、写入
            //方式一
            

            //方式二
            String data;
            while ((data = bufferedReader.readLine()) != null) {
                //一次读取一行，不包括换行符
                bufferedWriter.write(data);
                //加一个换行符
                bufferedWriter.newline();
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            //5、关闭流
            if (bufferedWriter != null) {
                try {
                    bufferedWriter.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (bufferedReader != null) {
                try {
                    bufferedReader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            //关闭外层流的同时，内存流也会自动的进行关闭，关于内层流的关闭，可以省略。
        }
    }