                        课程
                    
                        /后端开发
                        
                            /Java
                        
                        /JAVA遇见HTML——JSP篇

一直找不到错误，我是eclipse写的

<%@page import="java.util.*,java.net.*"%>

<%@ page language="java" contentType="text/html; charset=UTF-8" 
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<h1>用户登录</h1>
<%
	request.setCharacterEncoding("utf-8");
	String username="";
	String password = "";
	
	Cookie[] cookies = request.getCookies();
    if(cookies!=null&&cookies.length>0)
    {
         for(Cookie c:cookies)
         {
            if(c.getName().equals("username"))
            {
                 username =URLDecoder.decode(c.getValue(), "utf-8")  ;
            }
            if(c.getName().equals("password"))
            {
                 password =URLDecoder.decode(c.getValue(), "utf-8");
            }
         }
    }
%>
 <form action="dologin.jsp" name="login" method="post">
<table>
	<tr>
	<td>姓名：</td>
	<td><input type="text" name="username " value="<%=username %>" /></td>
	</tr>
	<tr>
	<td>密码：</td>
	<td>
		<input type="password" name="password" value="<%=password %>" />
	</td>
	</tr>
	<tr>
	<td colspan="2" ><input type="checkbox" name="useCookie" checked >十天内免登陆</td>
	</tr>
	<tr>
	<td colspan="2" ><input type="submit" value="提交" ></td>
	</tr>
</table>

</form>
<br>
<br>


</body>
</html>

这是log.jsp

<%@page import="java.util.*,java.net.*"%>

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<h1>登录成功</h1>
<hr>
<%
	request.setCharacterEncoding("utf-8");
	//判断用户是否选择记住密码
	String[] useCookie=request.getParameterValues("useCookie");
	if(useCookie!=null&&useCookie.length>0){
		//用户名和密码保存在cookie里
		String username = URLEncoder.encode(request.getParameter("username"),"utf-8");
		//使用URLEncoder解决无法在Cookie当中保存中文字符串问题
		String password=URLEncoder.encode(request.getParameter("password"), "utf-8");
		
		Cookie usernameCookie=new Cookie("username",username);
		Cookie passwordCookie=new Cookie("password",password);
		
		usernameCookie.setMaxAge(864000);
		passwordCookie.setMaxAge(864000);//最大生存期限10天
		response.addCookie(usernameCookie);
		response.addCookie(passwordCookie);
		
	}else{
		Cookie[] cookies=request.getCookies();
		if(cookies!=null&&cookies.length>0){
			for(Cookie c:cookies){
				if(c.getName().equals("username")||c.getName().equals("password")){
					c.setMaxAge(0);//设置cookie失效
					response.addCookie(c);//重新保存
				}
			}
			
		}
	}

%>

<a href="users.jsp" target="_blank">查看用户信息</a>
</body>
</html>

这是dologin.jsp

<%@page import="java.util.*,java.net.*"%>

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<h1>用户信息</h1>
<br>
<%
	request.setCharacterEncoding("utf-8");
	String username="";
	String password="";
	
	Cookie[] cookies=request.getCookies();
	if(cookies!=null&&cookies.length>0){
		for(Cookie c:cookies){
			if(c.getName().equals("username")){
				username=URLDecoder.decode(c.getValue(), "utf-8") ;
			}
			if(c.getName().equals("password")){
				password=URLDecoder.decode(c.getValue(), "utf-8");
			}
		}
		
	}
%>
用户名：<%=username %><br>
密码：<%=password %><br>

</body>
</html>

这是users.jsp