Integrated Case (no database)
servlet
@WebServlet("/userManage")
public class UserManage extends HttpServlet {
private Map<String, User> userMap = new HashMap<String,User>();
public UserManage(){
User user1 = new User("1","小明",20);
User user2 = new User("2","小红",30);
User user3 = new User("3","小刚",18);
User user4 = new User("4","小牛",27);
userMap.put("1",user1);
userMap.put("2",user2);
userMap.put("3",user3);
userMap.put("4",user4);
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
String type = req.getParameter("type");
if(StringUtils.isEmpty(type)){
type = "findAll";
}
switch (type){
case "delete":
String id = req.getParameter("id");
userMap.remove(id);
resp.sendRedirect("/userManage");
break;
case "findAll":
req.setAttribute("userList",userMap.values());
req.getRequestDispatcher("userList.jsp").forward(req,resp);
break;
case "update":
id = req.getParameter("id");
User user = userMap.get(id);
req.setAttribute("user",user);
req.getRequestDispatcher("/userUpdate.jsp").forward(req,resp);
break;
}
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("UTF-8");
String id = req.getParameter("id");
String name = req.getParameter("name");
String age = req.getParameter("age");
User user = new User(id,name,Integer.valueOf(age));
userMap.put(id,user);
resp.sendRedirect("/userManage");
}
}
List page
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<title>用户列表</title>
</head>
<body>
<a href="/userAdd.jsp">新增</a>
<table border="1px">
<tr>
<th>操作</th>
<th>用户号</th>
<th>姓名</th>
<th>年龄</th>
</tr>
<c:forEach items="${userList}" var="user">
<tr>
<td>
<a href="/userManage?type=update&id=${user.id}">编辑</a>
<a href="/userManage?type=delete&id=${user.id}">删除</a>
</td>
<td>${user.id}</td>
<td>${user.name}</td>
<td>${user.age}</td>
</tr>
</c:forEach>
</table>
</body>
</html>
Add page & Edit Page
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>用户新增</title>
</head>
<body>
<form action="/userManage" method="post">
用户名：<input name="id" id="id" type="text" /><br/>
姓名：<input name="name" id="name" type="text" /><br/>
年龄：<input name="age" id="age" type="text" /><br/>
<input type="submit" name="保存" value="保存" />
</form>
</body>
</html>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>用户编辑</title>
</head>
<body>
<form action="/userManage" method="post">
用户名：<input name="id" id="id" type="text" value="${user.id}" readonly/><br/>
姓名：<input name="name" id="name" type="text" value="${user.name}"/><br/>
年龄：<input name="age" id="age" type="text" value="${user.age}"/><br/>
<input type="submit" name="保存" value="保存" />
</form>
</body>
</html>