jsp 通过cookie 记住用户名博客分类： Java Web 记住用户名记住密码remember mecookie会话

程序员文章站 2024-02-23 20:27:58

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java web中登录时如何记住用户名呢?

具体思路:

登录界面如下:
jsp 通过cookie 记住用户名

博客分类： Java Web 记住用户名记住密码remember mecookie会话
在后台(Servlet 或struts 的action)中进行判断,若登录成功则通过HttpServletResponse 添加一个cookie.

在登录的jsp页面中,通过request 获取cookie数组,然后遍历,若找到相应的cookie,则把cookie的value设置到表单的对应文本框中.

具体代码如下:

登录的JSP页面中(核心代码):

<body>
<%
Cookie[] cookies = request.getCookies();
String username33="";
if (cookies != null) {
	for (Cookie c : cookies) {
		/*if ("password22".equals(c.getName())) {
			user.setPassword(URLDecoder.decode(c.getValue(), "utf-8"));
			continue;
		}*/
		if ("userEmail".equals(c.getName())) {
			username33=URLDecoder.decode(c.getValue(), "utf-8");
			break;
		}
	}
}
%>
<script type="text/javascript">
window.onload=function(){
var username1='<%=username33 %>';
//alert("username1:"+username1);
if(username1){
	if(username1!='' && username1!=null &&username1!=undefined){
		document.getElementsByName("user.username")[0].value=username1;
	}
}
}
</script>
...
</body>

后台的action:

if (isLogin) {
			
			//保存用户名(目前是邮箱)
			
				String emaiCookieName = "userEmail";
		        HttpServletRequest request=ServletActionContext.getRequest();
		        Cookie[] cookies = request.getCookies();
				boolean flag = false;
		        Cookie emailCook = null;
		        if (cookies != null)
		        {
		        	System.out.println("cookie 不为空");
		            for (Cookie c : cookies)
		            {

		                if (emaiCookieName.equals(c.getName()))
		                {
		                	System.out.println("找到了 "+emaiCookieName);
		                	System.out.println("cookie的值为 "+c.getValue());
		                    try {
								c.setValue(URLEncoder.encode(this.user.getUsername(), "utf-8"));
							} catch (UnsupportedEncodingException e) {
								e.printStackTrace();
							}
		                    emailCook = c;
		                    flag = true;
		                    break;
		                }
		            }
		            
		        }
		        if (!flag)
		        {
		        	System.out.println("没有找到 "+emaiCookieName);


		            try {
						emailCook = new Cookie(emaiCookieName, URLEncoder.encode(
								this.user.getUsername(), "utf-8"));
					} catch (UnsupportedEncodingException e) {
						e.printStackTrace();
					}
		        }

		            if (null != emailCook)
		            {
		            	 HttpServletResponse response=ServletActionContext.getResponse();
		            	if(!ValueWidget.isNullOrEmpty(issave) && issave.equalsIgnoreCase("save")){
			                emailCook.setMaxAge(10000000);
			               
			                response.addCookie(emailCook);
			                System.out.println("保存cookie");
			             }else{
			                	System.out.println("让 cookie 失效");
			                	emailCook.setMaxAge(0);
			                	response.addCookie(emailCook);
			             }
		            }

		           
			
			return Action.SUCCESS;
		}

源代码见附件

说明:

该项目使用maven 构建;

IDE:eclipse

数据库:mysql

登录地址:http://localhost:8080/shop_goods/user/loginInput.action