1.随机生成优惠码代码如下：

import java.util.Random;
/**
*功能：随机生成优惠码
*@author iamwiam
*
*/
public class Activatedcode {
 public int ACTIVATEDCODENUM = 200; //生成的优惠码数量
 Random random = new Random();
 String candicatedCode = "abcedefghijklmnopqrstuvwxyz";//优惠码包含小写字母
 candicatedCode+=candicatedCode.toUpperCase()；//优惠码包含大写字母
 candicatedCode+="12345670";//优惠码包含阿拉伯数字
 for(int i=0; i< ACTIVATEDCODENUM;i++){
 String res ="";
 for(int j=0;j<8;j++){
 res+=candicatedCode.charAt(random.nextInt(candicatedCode.lenght()));
 }
 System.out.println(res);//随机生成200个8位的优惠码
 }
}

2.将优惠码保存在数据库中

private static void insertToMySql(String res){ 
int n = 0; 
try{ 
Class.forName(“com.mysql.jdbc.Driver”); 
Connection connection = DriverMannager.getConnection(“jdbc:mysql://127.0.0.1/tb_act_code”,”zy”,”IamWiam”); 
String sql = “insert into checkNum(value) values(?)”; 
PreparedStatement ps = connection.prepareStatement(sql); 
ps.setObject(1,res); //占位符顺序从1开始，第一个参数是占位符的位置，第二个参数是占位符的值 
n = ps.executeUpdate(); 
}catch(ClassNotFoundException e){ 
e.printStackTrace(); 
}catch(SQLException e){ 
e.printStackTrace(); 
} 
}

3.整合

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Random;
/**
 * 功能：随机生成优惠码
 * @author iamwiam
 *
 */
public class Activatedcode {
 public static void main(String[] args) {
 final int ACTIVATEDCODENUM = 200;
 Random random = new Random();
 String candicatedCode = "abcdefghijklmnopqrstuvwxyz";
 candicatedCode+=candicatedCode.toUpperCase();
 candicatedCode+="12345670";
 for(int i=0;i<ACTIVATEDCODENUM;i++){
 String res ="";
 for(int j=0;j<8;j++){
 res+=candicatedCode.charAt(random.nextInt(candicatedCode.length()));
 }
// String pwd = Activatedcode.getMD5(Activatedcode.getMD5(res));
 insertToMysql(res);
 }
 }
 private static void insertToMysql(String res) {
 int n=0;
 try {
 Class.forName("com.mysql.jdbc.Driver");
 Connection connection = DriverManager.getConnection(
 "jdbc:mysql://127.0.0.1/new2017", "zy", "IamWiam");
 String sql = "insert into checkNum(value) values(?)";
 PreparedStatement ps = connection.prepareStatement(sql);
 ps.setObject(1, res);
 n = ps.executeUpdate();
 } catch (ClassNotFoundException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 } catch (SQLException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }
 }
}

4.结果如下