转换流InputStreamReader、OutputStreamWriter

InputStreamReaderDemo:

 1 import java.io.*;
 2 //为方便演示便省略异常处理。
 3 class SystemDemo2
 4 {
 5     public static void main(String[] args)throws IOException
 6     {
 7         InputStream in = System.in;
 8         InputStreamReader ins = new InputStreamReader(in);
 9         BufferedReader bufr = new BufferedReader(ins);
10         while (true)
11         {
12             String s = bufr.readLine();
13             System.out.println(s.toUpperCase());
14             if (s.equals("over"))
15             {
16                 break;
17             }
18         }
19         //bufr.close();爆出了无法访问的语句，可能是此缓存区最终的数据时键盘所以无需关闭流。
20     }
21 }

键盘的最常见写法：

BufferedReader bufr = new BufferedReader(new InputStream(System.in));

OutputStreamWriterDemo:

 1 import java.io.*;
 2 class OutputStreamReaderDemo
 3 {
 4     public static void main(String[] args) throws IOException
 5     {
 6         OutputStream out = System.out;//创建输出对象。
 7         OutputStreamWriter outw = new OutputStreamWriter(out);//转换流对象，将需要转换的字节流作为参数传入转换流对象
 8         BufferedWriter bufw = new BufferedWriter(outw);//缓冲区
 9         bufw.write("afd");//调用写出方法
10         bufw.flush();//刷新
11         bufw.close();//关闭资源
12 //        //三行变一行输出方式
13 //        BufferedWriter bufw = new BufferedWriter(new OutputStreamWriter(System.out));
14     }
15 }

InputStream、OutputSreamDemo：（综合）

 1 import java.io.*;
 2
 3 class  TransStreamDemo
 4 {
 5     public static void main(String[] args) throws IOException
 6     {
 7         //获取键盘录入对象。
 8         //InputStream in = System.in;
 9
10         //将字节流对象转成字符流对象，使用转换流。InputStreamReader
11         //InputStreamReader isr = new InputStreamReader(in);
12
13         //为了提高效率，将字符流进行缓冲区技术高效操作。使用BufferedReader
14
15         //BufferedReader bufr = new BufferedReader(isr);
16
17
18         //键盘的最常见写法。
19         BufferedReader bufr =
20                 new BufferedReader(new InputStreamReader(System.in));
21
22
23
24
25
26
27 //        OutputStream out = System.out;
28 //        OutputStreamWriter osw = new OutputStreamWriter(out);
29 //        BufferedWriter bufw = new BufferedWriter(osw);
30         BufferedWriter bufw = new BufferedWriter(new OutputStreamWriter(System.out));
31
32
33
34
35         String line = null;
36
37         while((line=bufr.readLine())!=null)
38         {
39             if("over".equals(line))
40                 break;
41             bufw.write(line.toUpperCase());
42             bufw.newLine();
43             bufw.flush();
44         }
45
46         bufr.close();
47
48     }
49 }