1 public class wori                                    //先用InputStreamReader套System.in，再用BufferedReader套是常用方法 2 { 3     public static void main(String args[]) 4     { 5         InputStreamReader a = new InputStreamReader(System.in);                // System.in是InputStream父类的引用，用于键盘输入 6         BufferedReader b = new BufferedReader(a);                               7         String s = null; 8         try 9         {10             while((s = b.readLine()) != null)                //使用BufferedReader的方法readLine()11             {12                 if(s.equalsIgnoreCase("exit"))                //13                 {14                     break;15                 }16                 System.out.println(s.toUpperCase());17             }18             b.close();                                                    //b close即可19         }20         catch(IOException e)21         {22             e.printStackTrace();23         }24     }25 }

 1 public class wori 2 { 3     public static void main(String args[]) 4     { 5         ByteArrayOutputStream baos = new ByteArrayOutputStream();       //分配内存给一个字节数组，以此为节点 6         DataOutputStream dos = new DataOutputStream(baos);              // 7         try 8         { 9             dos.writeDouble(Math.random());                            //10             ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());  //toByteArray()返回一个字节数组作为节点11             DataInputStream dis = new DataInputStream(bais);12             System.out.println(dis.readDouble());                   //13             dos.close();14             dis.close();15         }16         catch(IOException e)17         {18             System.exit(-1);19         }20         21     }22 }

 1 public class wori 2 { 3     public static void main(String args[]) 4     { 5         PrintStream ps = null; 6         try 7         { 8             FileOutputStream fos = new FileOutputStream("d:/1.txt"); 9             ps = new PrintStream(fos);10         }11         catch(IOException e)12         {13             System.exit(0);14         }15         System.setOut(ps);                               //16         int i = 0;17         while(i < 100)18         {19             System.out.println(i);20             i++;21         }22         ps.close();23     }24 }

 1 public class wori 2 { 3     public static void main(String args[]) 4     { 5         try{ 6         FileOutputStream a = new FileOutputStream("d:/1.txt"); 7         FileInputStream b = new FileInputStream("d:/1.txt"); 8         ObjectOutputStream oos = new ObjectOutputStream(a); 9         ObjectInputStream ois = new ObjectInputStream(b);10         Animal n = new Animal();11         oos.writeObject(n);                        //12         oos.flush();13         oos.close();14         Animal n1 = (Animal)ois.readObject();                       //15         ois.close();16         System.out.println(n1.a );17         System.out.println( n1.k);18         }19         catch(IOException e)20         {21             22         }23         catch(ClassNotFoundException o)24         {25             26         }27         28     }29 }