//生成验证码
String z="abcdefghigklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
Random r= new Random();
//第一种方法
int a=r.nextInt(61);
int b=r.nextInt(61);
int c=r.nextInt(61);
int d1=r.nextInt(61);
String s1=z.substring(a,a+1);
String s2=z.substring(b,b+1);
String s3=z.substring(c,c+1);
String s4=z.substring(d1,d1+1);
String ss=s1+s2+s3+s4;
System.out.println("验证码="+ss);
//第二种方法
for(int i=0;i<4;i++){
int g=r.nextInt(z.length());
System.out.print(z.substring(g,g+1));
}System.out.println();
//第三种方法
String [] gg=z.split("");
for(int i=0;i<4;i++){
int q=r.nextInt(z.length()-1);
System.out.print(gg[q]); }
System.out.println();
//随机彩票
Random ra= new Random();
System.out.println("随机彩票:");
for(int n=0;n<7;n++){
System.out.print(" "+ra.nextInt(30));
}
![](https://images2015.cnblogs.com/blog/867506/201601/867506-20160114170727928-1713949820.png)