Question

jsp+servlet实现cookie保存用户信息的问题。没分了，大神么帮忙看看吧

小弟写了个登陆的模块，想用cookie保存用户的信息，再次打开浏览器登陆时，cookie中的信息就可以显示在登陆的表单上面。写了半天，cookie是存进去了，就是显示在表单上这点一直想不明白。下面是我的代码：
Jsp部分：
<form action="${pageContext.request.contextPath }/before/LoginServlet" method="POST">
<table border="1px">
<tr>
<td>用户名:</td>
<td><input type="text" name="username" value="${name }"/></td>
</tr>
<tr>
<td>密 码:</td>
<td><input type="password" name="password" value="${pass }"/></td>
</tr>
<tr>
<td>验证码:</td>
<td><input type="text" name="checkcode"/></td>
<td><img src="${pageContext.request.contextPath}/images/checkcode.jpg" title="点击图片换一张" onclick="changeImg(this)"/></td>
</tr>
<tr>
<td><input type="submit" value="登录"/></td>
</tr>
</table>
<font color="red" size="+2">${error }</font>
</form>
UserDao userDao = new UserDaoImpl();
String username = request.getParameter("username");
String password = request.getParameter("password");
String checkcode = request.getParameter("checkcode");
String codes = (String) request.getSession().getAttribute("checkcode");

Answer 1

<script type="text/javascript">
function setCookie(name, value) {
    var exp = new Date();
    exp.setTime(exp.getTime() + 30 * 24 * 60 * 60 * 1000);
    document.cookie = name + "=" + escape(value) + ";expires=" + exp.toGMTString();
}
function getCookie(name) {
    var arr = document.cookie.match(new RegExp("(^| )" + name + "=([^;]*)(;|$)"));
    if (arr == null) {
        return null;
    }
    return unescape(arr[2]);
}
</script>
<form action="login">
    <table>
        <tr>
            <td>username :</td>
            <td>
                <input id="username_input" type="text" name="username" label="username"
                    onblur="setCookie('username_input',this.value);" />
            </td>
        </tr>
        <tr>
            <td>password :</td>
            <td>
                <input type="password" name="password" label="password" />
            </td>
        </tr>
        <tr>
            <td align="right" colspan="2">
                <button type="submit">submit</button>
            </td>
        </tr>
    </table>
</form>
<script type="text/javascript">
var username_input = getCookie("username_input");
if(username_input!=null){
    document.getElementById("username_input").value = username_input;
}
</script>

Answer 2

session是会话，退出无效。