class RegexDemo{
    public static void main(String[]args){
        checkQQ();
    }
    static void checkQQ(){
        /**
        *对QQ号进行校验，
        *要求：5-15位，第一位不能为0,不能有非法字符
        */
        String QQ = "a01b33333";
        if( ! (QQ.length()< 5 || QQ.length() >15)){
            if(! QQ.startsWith("0")){
                char[] arr= QQ.toCharArray();
                boolean flag = true;
                for(int i =0;i< arr.length;i++){
                    if( arr[i]<'0' || arr[i] >'9'){
                        flag =false;
                        break;
                    }                
                }            
                if(flag)    
                    System.out.println("QQ号:"+QQ);
                else 
                    System.out.println("非法QQ号!");
            }
            else{
                System.out.println("QQ号不能以0开头！");
            }
        }
        else {
            System.out.println("QQ号超度不符合要求！");
        }
    }
}