IO流之字符流-1

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();

    }