Java缓冲流

BufferedReader和BufferedWriter类创建的对象称为缓冲输入、输出流，两者增强了读写文件的能力。BufferedReader流和BufferedWriter流，二者的源和目的地必须是字符输入流reader和字符输出流writer。

BufferedReader和BufferedWriter类的构造方法分别是：

BufferedReader(Reader in);

BufferedWriter(Writer out);

BufferedReader流能够读取文本行，方法是readLine();

BufferedWriter流有一个独特的想问你那写入一个回车符的方法newline()；

写一个小例子加深记忆：

import java.io.*;
import java.util.StringTokenizer;

public class Example10_7 {
    public static void main(String[] args) {
        File fRead = new File("D:/JavaProject/JavaShiYan/src/com/java/zhang10/","test.txt");
        File fWrite = new File("D:/JavaProject/JavaShiYan/src/com/java/zhang10/","result.txt");
        try{
            Reader in = new FileReader(fRead);
            BufferedReader bufferedReader = new BufferedReader(in);
            Writer out = new FileWriter(fWrite,true);
            BufferedWriter bufferedWriter = new BufferedWriter(out);
            String str = null;
            while ((str=bufferedReader.readLine())!=null){
//                StringTokenizer会分割句子，以指定的符号或者标记，默认可以是空格回车等
                StringTokenizer fenxi = new StringTokenizer(str);
//                StringTokenizer类的countTokens方法会统计分割后的字符串
                int count = fenxi.countTokens();
                str = str+" 句子中单词的个数"+count;
                bufferedWriter.write(str);
                bufferedWriter.newline();
            }
            bufferedWriter.close();
            out.close();
            in = new FileReader(fRead);
            bufferedReader = new BufferedReader(in);
            String s = null;
            System.out.println(fWrite.getName()+"内容是：");
            while ((s=bufferedReader.readLine())!=null){
                System.out.println(s);
            }
            bufferedReader.close();
            in.close();
        }catch (IOException e){
            System.out.println(e);
        }
    }
}

test文件存在内容且内容是这样：

I am chinese
I love CHINA
Happy every day

result文件是空文件，运行后是这样;

I am chinese 句子中单词的个数3
I love CHINA 句子中单词的个数3
Happy every day 句子中单词的个数3