10.4 缓冲流 BufferedReader & BufferedWriter& 缓冲流特殊功能readLine

package day10_io_fileWrite_Read.buffer_stream;

import java.io.*;

/*
 * BufferedWriter:将文本写入字符输出流，缓冲各个字符，从而提供单个字符、数组和字符串的高效写入。
 * BufferedReader:从字符输入流中读取文本，缓冲各个字符，从而实现字符、数组和行的高效读取。
 */
public class BufferedStream {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new FileReader("c.txt")); //bufferedreader(reader)
        BufferedWriter bw = new BufferedWriter(new FileWriter("copy.txt"));

//        //一次读写一个字符
//        int len;
//        while((len=br.read())!=-1) {
//            bw.write(len);
//        }
//
        //一次读写一个数组
        char[] arr = new char[1024];
        int len1;
        while((len1=br.read(arr))!=-1) {
            bw.write(arr);
        }


        bw.close();
        br.close();
    }
}

package day10_io_fileWrite_Read.buffer_stream;

import java.io.*;

/*
 * 缓冲流的特殊功能：
 * BufferedWriter
 *         void newLine():写一个换行符，这个换行符由系统决定
 * BufferedReader
 *         String readLine():一次读取一行数据，但是不读取换行符
 */
public class BufferLine {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new FileReader("b.txt"));
        BufferedWriter bw = new BufferedWriter(new FileWriter("copy.txt"));

        /*一次读取一行
        String line = br.readLine();
        System.out.println(line);
        line = br.readLine();
        System.out.println(line);//当行读完时返回为null
        */

        String len;
        while((len=br.readLine())!=null) {
            bw.write(len);
            bw.newLine();
            bw.flush();
        }


        bw.close();
        br.close();
    }
}