需求：模拟登录
如果登录了，首页显示登录用户名
如果没有登录，提示用户登录
Paste_Image.png
User.java
public class User {
private int id;
private String name;
private String password;
public User(int id,String name,String password){
this.id = id;
this.name = name;
this.password = password;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
LoginServlet
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("utf-8");
String name = req.getParameter("name");
String password = req.getParameter("password");
resp.setContentType("text/html;charset=utf-8");
if (name.equals("丁昌江")){
if (password.equals("1111")){
HttpSession session = req.getSession();
session.setAttribute("name",name);
//这里是把post过来的请求转发到UserListServlet
req.getRequestDispatcher("/UserListServlet").forward(req, resp);//
}else{
resp.getWriter().write("密码错误");
}
}else{
resp.getWriter().write("用户名错误");
}
}
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req, resp);
}
}
UserListServlet
public class UserListServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
List<User>list = new ArrayList<User> ();
list.add(new User(1,"a","a-1"));
list.add(new User(1,"a","a-1"));
list.add(new User(1,"a","a-1"));
request.setAttribute("userList",list);
request.getRequestDispatcher("/userList.jsp").forward(request, response);
}
}
login.jsp
<body>
<form action="${pageContext.request.contextPath}/LoginServlet" method="post">
用户名：<input type="text" name="name"/><br/>
密码：<input type="password" name="password"/><br/>
<button type="submit">登录</button>
</form>
</body>
userList.jsp
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<link rel="stylesheet" href="//cdn.bootcss.com/bootstrap/3.3.5/css/bootstrap.min.css">
<style type="text/css">
table{
margin: 0px auto;
border: 1px solid #223344;
text-align:center;
}
table td,th{
border: 1px solid #112233;
text-align: center;
}
</style>
</head>
<body>
<c:choose>
<c:when test="${empty sessionScope.name}">
请先<a href="${pageContext.request.contextPath}/login.jsp">登录</a><br/>
</c:when>
<c:otherwise>
欢迎${sessionScope.name}回来
</c:otherwise>
</c:choose>
<table class="table table-bordered">
<caption>员工信息统计</caption>
<tr>
<th>编号</th>
<th>姓名</th>
<th>密码</th>
</tr>
<c:forEach items="${userList}" var="user">
<tr>
<td>${user.id }</td>
<td>${user.name }</td>
<td>${user.password }</td>
</tr>
</c:forEach>
</table>
</body>
</html>
login.gif
