Java基础之IO流，转换流应用InputStreamReader,OutputStreamWriter

import java.io.*;

class SystemInDemo
{
    /*
        以键盘录入与屏幕输出为例
    */
    public static void main(String[] args) throws IOException
    {        
        //改变标准输入与输出设备实例文件复制操作
        System.setIn(new FileInputStream(new File("BufferedCopyFileDemo.java")));
        System.setOut(new PrintStream(new File("hah.txt")));
    
        //字节流->字符流
        //字符流->字节流
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        String line = null;
        while((line=br.readLine())!=null)
        {
            if("over".equals(line))
                break;
            
            bw.write(line);
            bw.newLine();
            bw.flush();
        }
        
        br.close();
        
        /*
        //读取字节流
        InputStream inputStream = System.in;
        StringBuilder sb = new StringBuilder();
        int ch = 0;
        while((ch=inputStream.read())!=-1)
        {
            if('\r'==ch)
                continue;
            if('\n'==ch)
            {
                if(sb.toString().equals("over"))
                    break;
                
                System.out.println(sb.toString());
                sb.delete(0,sb.length());
            }
            else
                sb.append((char)ch);
        }
                
        inputStream.close();
        */
    }
}