输入输出流

PrintWriter和PrintStream类的作用和用法:

  stream   是byte方式的，writer，reader是char的，char是2个byte。文本是基于char的，writer,reader替你做了这个转化，所以建立writer的时候，一般要一个stream做参数。  

BufferedReader:

        FileReader reder=new FileReader(new File("c:\\test.txt"));
        BufferedReader bf=new BufferedReader(reder);
        while(bf.ready())
        {
            System.out.println(bf.readLine());

        }

BufferedWriter:

        FileWriter writer=new FileWriter("c:/test.txt",true);
        BufferedWriter bw=new BufferedWriter(writer);

      String a="我爱JAVA,哈哈\n哈哈哈哈哈哈";
      FileWriter fw=new FileWriter("c:/test.txt");
      BufferedWriter bw0=new BufferedWriter(fw);
      bw0.write(a);
      bw0.newLine();
      bw0.close();

从控制台输入后再输出：

String s="";
        System.out.println("Enter a character Please ");
        try
        {
            int q;
            BufferedReader in= new BufferedReader(new InputStreamReader(System.in));
            s=in.readLine();
            do{
                System.out.println(s);
            }while((q=in.read())!=-1);
            System.out.println(q);
        } catch(IOException e){};