新改的生成验证码

package yanzhengma;
import java.math.*;
import java.util.Random;
import java.util.Scanner;
public class RandomStr {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String str="ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
StringBuilder sb=new StringBuilder(6);
char[] ch=new char[100];
String[] q=new String[100];
String[] m=new String[100];
String[] s=new String[100];
int k=-1;
int e=1;
while(e==1) {
for(int i=0;i<6;i++)
{
ch[i]=str.charAt(new Random().nextInt(str.length()));
q[i]=String.valueOf(ch[i]);
if(i==5)k++;
}
m[k]=q[0]+q[1]+q[2]+q[3]+q[4]+q[5];
s[k]=m[k];
for(int i=1;i<k;i++) {
if(s[k]==s[i]) {
k--;
continue;
}
}
System.out.println(m[k]);
System.out.println("是否继续生成验证码，1为是，0为否");
e=sc.nextInt();
}
}
}