两个小的java程序，用于练习java基本语法

1、输入两个数，求其加减乘除。用窗口的形式呈现

 import javax.swing.JOptionPane;
 
 public class JJCC {
     public static void main(String[] args)
     {
         String firstNumber,secondNumber;
         int number1,number2;
         int he,cha,ji,shang;
         firstNumber = JOptionPane.showInputDialog
                 ("input the first integer please");
         secondNumber = JOptionPane.showInputDialog
                 ("inout the second integer please");
         number1 = Integer.parseInt(firstNumber);
         number2 = Integer.parseInt(secondNumber);
         he = number1 + number2;
         cha = number1 - number2;
         ji = number1 * number2;
         shang = number1 / number2;
         JOptionPane.showMessageDialog(null, "number1 + number2 is "
                 +he+"\nnumber1 - number2 is "+cha+"\nnumber1 *"
                         + " number2 is "+ji+"\nnumber1 / number2 is "+shang
                         ,"Results", JOptionPane.PLAIN_MESSAGE);
     }
 }

2、生成一个6位的随机字符串验证码（以窗口的形式）（位数可改）

 import javax.swing.JOptionPane;
 
 public class RandomStr {
 //    public void createRandomStr(int weishu)
 //    {
 //        String str = "";
 //        for(int i=1;i<=weishu;i++)
 //        {
 //            //生成一个表示a~z的ASCII的随机数
 //            int intValue = (int)(Math.random()*26+97);
 //            //将此随机数转化为其对应的字母并连接在str后面
 //            str = str + (char)intValue;
 //        }
 //    }
 
     public static void main(String[] args) {
     //生成一个6位的由小写字母组成的随机字符串
         int weishu=6;
         String str = "";
         for(int i=1;i<=weishu;i++)
         {
             //生成一个表示a~z的ASCII的随机数
             int intValue = (int)(Math.random()*26+97);
             //将此随机数转化为其对应的字母并连接在str后面
             str = str + (char)intValue;
         }
     //随机字符串生成完毕
         String inputStr;
         inputStr = JOptionPane.showInputDialog("请输入以下验证码\n"+str);
         if(inputStr.equals(str))
         {
             JOptionPane.showMessageDialog(null, "验证成功");
         }
         else
         {
             JOptionPane.showMessageDialog(null, "抱歉，验证失败");
         }
     }
 
 }