amp什么意思啊_登录 Login

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关于注册页面和登录页面的业务流程

form表单中确定action提交地址 method 确定提交的方法—》写出相对应的Servlet,假如接受的数据不多 ，那么用

String username = request.getParameter(“username”); String password = request.getParameter(“password”);接受账户和密码 假如数据多 那么需要工具类集合对数据进行处理 ，对于regist需要建立对应的数据库 和domain—>生成get 和set方法，便于插入数据，将这些数据进行转发，request.getRequestDispatcher(“/login.jsp”).forward(request, response);登录成功 跳转首页面response.sendRedirect(request.getContextPath());详细代码和效果图 如下

package cn.lijun.Demo

import java.io.IOException; import java.sql.SQLException;

import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse;

import org.apache.commons.dbutils.QueryRunner; import org.apache.commons.dbutils.handlers.BeanHandler;

import com.ithiema.register.User; import com.ithiema.utils.DataSourceUtils;

public class LoginServlet extends HttpServlet {

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //1 解决乱码 request.setCharacterEncoding(“UTF-8”);

//2、获得用户名和密码 String username = request.getParameter(“username”); String password = request.getParameter(“password”);

User login = null; try { login = login(username,password); } catch (SQLException e) { e.printStackTrace(); } //3、通过user是否为null判断用户名和密码是否正确 if(login!=null){ //用户名和密码正确 //登录成功 跳转到网站的首页 response.sendRedirect(request.getContextPath()); }else{ //4用户名或密码错误 //跳回当前login.jsp //使用转发 转发到login.jsp 向request域中存储错误信息 request.setAttribute(“loginInfo”, “用户名或密码错误”); //转发 request.getRequestDispatcher(“/login.jsp”).forward(request, response); }

}

public User login(String username,String password) throws SQLException{ QueryRunner runner = new QueryRunner(DataSourceUtils.getDataSource()); String sql = “select * from user where username=? and password=?”; //只有一个对象 User user = runner.query(sql, new BeanHandler<User>(User.class), username,password); return user; }

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }

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