验证码识别技术研究现状（验证码识别java）

java怎么实现随机4个带有数字和字母的验证码？

参考代码：

private String generateWord() {

String[] beforeShuffle = new String[] { "2", "3", "4", "5", "6", "7",

"8", "9", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J",

"K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V",

"W", "X", "Y", "Z" };

List list = Arrays.asList(beforeShuffle);

Collections.shuffle(list);

StringBuilder sb = new StringBuilder();

for (int i = 0; i < list.size(); i++) {

sb.append(list.get(i));

}

String afterShuffle = sb.toString();

String result = afterShuffle.substring(5, 9);

return result;

}

求java表单验证制作注册页面的代码？

简单举例：

function checkForm(){

var username =document.getElementById('username').value;

var pwd=document.getElementById('pwd').value;

var rePwd=document.getElementById('rePwd').value;

var email=document.getElementById('email').value;

var checkAgree=document.getElementById('checkAgree');

var form=document.getElementById('form');

var emailReg=/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/ ;

if(username==''){

alert('用户名不能为空');

document.getElementById('username').focus();

return false;

}

if(pwd==""){

//不能为空

}

if(pwd.lentht

//长度不能小于6位

}

if(pwd!=rePwd){

//密码确认密码不一致

}

//日期的话建议用日历控件 可以参考网上自己弄一弄

if(!emailReg.test(email)){

//邮箱格式不对

}

if(!checkAgree.checked){

//尚未统一协议

}

//所有验证通过之后提交表单

();

}

写了基本的东西出来 还是希望你能自己研究研究 自己动手搞定