1、编写表单前端页面
<form action="UserLogin" method="post">
用户名：<input type="text" name="username" ><br/>
密码：<input type="password" name="password"><br/>
<input type="submit" value="登录">
</form>
2、Servlet的实现(UserLogin)，用来接受数据和判断：
public class UserLogin extends HttpServlet {
private static final long serialVersionUID = 1L;
public UserLogin() {
super();
}
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
try {
//接受表单提交的数据
String username = req.getParameter("username");
String password = req.getParameter("password");
//封装到实体对象中，通过这个对象传递数据
User user = new User();
user.setUNAME(username);
user.setUPASS(password);
//调用业务层处理数据
UserService userservice = new UserService();
//将返回的数据保存，用户存在即返回这个用户的User对象，否则返回null
User existuser = userservice.login(user);
//判断是否存在这个用户
if(existuser!=null) {
resp.getWriter().write("Welcom! "+ user.getUNAME());
}else {
resp.getWriter().write("Login Failed...");
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
3、service的实现(UserService)：
public class UserService {
public User login(User user) throws SQLException {
UserDao userdao = new UserDao();
return userdao.login(user);
}
}
4、DAO的实现(UserDao)：
public class UserDao {
public User login(User user) throws SQLException {
QueryRunner query = new QueryRunner(JDBCUtils.getDataSource());
String sql = "select * from userinfo where uname=? and upass=?";
User existuser = query.query(sql, new BeanHandler<User>(User.class),user.getUNAME(),user.getUPASS());
return existuser;
}
}
