转换流InputStreamReader,OutputStreamWriter
import java.io.*;/*规律：1，明确数据源和数据目的。其实就是在明确到底是输入流还是输出流。2，明确操作的数据是否是纯文本数据。其实就是在明确到底是用字符流还是字节流。需求：1，通过键盘录入将数据打印在控制台上。2，复制一个文本文件。3，将键盘录入的数据存储到一个文件中。4，将一个文件打印在控制台上。*/class TransStream{public static void main(String[] args) throws IOException{System.setIn(new FileInputStream("CopyBmp.java"));System.setOut(new PrintStream("zz.txt"));//InputStream in = System.in;//InputStreamReader isr = new InputStreamReader(in);//BufferedReader bufr = new BufferedReader(isr);BufferedReader bufr = new BufferedReader(new InputStreamReader(System.in));//OutputStream out = System.out;//OutputStreamWriter osw = new OutputStreamWriter(out);//BufferedWriter bufw = new BufferedWriter(osw);BufferedWriter bufw = new BufferedWriter(new OutputStreamWriter(System.out));String line = null;while((line=bufr.readLine())!=null){if("over".equals(line))break;bufw.write(line.toUpperCase());bufw.newLine();bufw.flush();}bufw.close();bufr.close();}public static void readIn()throws IOException{StringBuilder sb = new StringBuilder();int ch = 0;while(true){InputStream in = System.in;ch = in.read();if(ch=='\r')continue;if(ch=='\n'){String s = sb.toString();if("over".equals(s))return ;//break;System.out.println(s.toUpperCase());sb.delete(0,sb.length());}elsesb.append((char)ch);}}}?