Reader和Writer抽象类

 　　Reader是定义java的流式字符输入流模式的抽象类

　　Writer是定义流式字符输出的抽象类

　　　　该类的方法都返回void值并在错条件下抛出IOException异常

 

FileReader和FileWriter

　　FileReader表示可以读取文件内容的Reader类

　　FileWriter  表示可以写文件的Weiter类

　　　　默认有缓冲区,缓冲区默认大小为8k

 　 　　

public static void main(String[] args) throws IOException {            FileReader fileReader=new FileReader(new File("D:\\zhangsan.txt"));            FileWriter fWriter=new FileWriter(new File("D:\\e.txt"));            char[]buff=new char[100];            int data=0;//实际读到的字符个数            while((data=fileReader.read(buff))!=-1) {                fWriter.write(buff, 0, data);                //fWriter.flush(); 强制关闭            }            fileReader.close();            fWriter.close();        }

 

BufferedReader和BufferedWriter

 　　　　BufferedReader通过缓冲输入提高性能

　　　　 BufferedWriter通过缓冲输出提高性能

public static void main(String[] args) throws IOException {        FileReader fileReader = new FileReader(new File("D:\\\\zhangsan.txt"));        BufferedReader bufferedReader = new BufferedReader(fileReader);        FileWriter fileWriter = new FileWriter(new File("D:\\\\e.txt"));        BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);        String line = null;        while ((line = bufferedReader.readLine()) != null) {            System.out.println(line);            bufferedWriter.write(line);            bufferedWriter.newLine();// 换行            //bufferedWriter.flush();        }        bufferedReader.close();        bufferedWriter.close();    }