超市订单管理系统updating
Posted hitenine
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SMBMS
数据库:
项目搭建准备工作
使用Maven
搭配一个maven web项目
配置Tomcat
测试项目是否能够跑起来
导入项目中会遇到的jar包
jsp, Servlet, mysql驱动, jstl, standard...创建包结构
编写实体类
ORM映射:表-类映射
编写基础公共类
数据库配置文件
driver=com.mysql.cj.jdbc.Driver url=jdbc:mysql://localhost:3306/smbms?useSSL=true&useUnicode=true&characterEncoding=utf-8 username=root password=123456
编写数据库公共类
package com.hitenine.dao; import java.io.IOException; import java.io.InputStream; import java.sql.*; import java.util.Properties; //操作数据库的公共类 public class BaseDao { private static String driver; private static String url; private static String username; private static String password; //静态代码块,类加载的时候就初始化了 static { Properties properties = new Properties(); //通过类加载器读取对应的资源 InputStream is = BaseDao.class.getClassLoader().getResourceAsStream("db.properties"); try { properties.load(is); } catch (IOException e) { e.printStackTrace(); } driver = properties.getProperty("driver"); url = properties.getProperty("url"); username = properties.getProperty("username"); password = properties.getProperty("password"); } //获取数据库的连接 public static Connection getConnection() { Connection connection = null; try { Class.forName(driver); connection = DriverManager.getConnection(url, username, password); } catch (Exception e) { e.printStackTrace(); } System.out.println("ok"); return connection; } /* 有些bug */ //编写查询公共方法 public static ResultSet execute(Connection connection, PreparedStatement preparedStatement, ResultSet resultSet, String sql, Object[] params) throws SQLException { //预编译的sql,在后面直接执行就可以了 preparedStatement = connection.prepareStatement(sql); for (int i = 0; i < params.length; i++) { //setObject,占据符从1开始,但是我们的数组是从0开始的 preparedStatement.setObject(i + 1, params[i]); } resultSet = preparedStatement.executeQuery(); return resultSet; } //编写增删改公共方法 public static int execute(Connection connection, PreparedStatement preparedStatement, String sql, Object[] params) throws SQLException { //预编译的sql,在后面直接执行就可以了 preparedStatement = connection.prepareStatement(sql); for (int i = 0; i < params.length; i++) { //setObject,占据符从1开始,但是我们的数组是从0开始的 preparedStatement.setObject(i + 1, params[i]); } int updateRows = preparedStatement.executeUpdate(); return updateRows; } //释放资源 public static boolean closeResource(Connection connection, PreparedStatement preparedStatement, ResultSet resultSet) { boolean flag = true; if (null != resultSet) { try { resultSet.close(); //GC回收 resultSet = null; } catch (SQLException e) { e.printStackTrace(); flag = false; } } if (null != preparedStatement) { try { preparedStatement.close(); //GC回收 preparedStatement = null; } catch (SQLException e) { e.printStackTrace(); flag = false; } } if (null != connection) { try { connection.close(); //GC回收 connection = null; } catch (SQLException e) { e.printStackTrace(); flag = false; } } return flag; } }
编写字符编码过滤器
导入静态资源
登录功能实现
编写前端页面
设置首页
<!--设置首页--> <welcome-file-list> <welcome-file>login.jsp</welcome-file> </welcome-file-list>
编写dao层登录用户登录的接口
//得到要登录的用户 public User getLoginUser(Connection connection, String userCode) throws SQLException;
编写dao接口的实现类
package com.hitenine.dao.user; import com.hitenine.dao.BaseDao; import com.hitenine.pojo.User; import javax.servlet.http.HttpServlet; import java.sql.*; public class UserDaoImpl extends HttpServlet implements UserDao{ //得到要登录的用户 @Override public User getLoginUser(Connection connection, String userCode) throws SQLException { PreparedStatement pstm = null; ResultSet rs = null; User user = null; if (null != connection) { String sql = "select * from smbms_user where userCode=?"; Object[] params = {userCode}; Statement statement = connection.createStatement(); rs = BaseDao.execute(connection, pstm, rs, sql, params); if (rs.next()) { user = new User(); user.setId(rs.getInt("id")); user.setUserCode(rs.getString("userCode")); user.setUserName(rs.getString("userName")); user.setUserPassword(rs.getString("userPassword")); user.setGender(rs.getInt("gender")); user.setBirthday(rs.getDate("birthday")); user.setPhone(rs.getString("phone")); user.setAddress(rs.getString("address")); user.setUserRole(rs.getInt("userRole")); user.setCreatedBy(rs.getInt("createdBy")); user.setCreationDate(rs.getTimestamp("creationDate")); user.setModifyBy(rs.getInt("modifyBy")); user.setModifyDate(rs.getTimestamp("modifyDate")); } BaseDao.closeResource(null, pstm, rs); } return user; } }
业务层接口
//用户登录 public User login(String userCode, String password);
业务层实现类
package com.hitenine.service.user; import com.hitenine.dao.BaseDao; import com.hitenine.dao.user.UserDao; import com.hitenine.dao.user.UserDaoImpl; import com.hitenine.pojo.User; import java.sql.Connection; import java.sql.SQLException; public class UserServiceImpl implements UserService { //业务层都会调用dao层,所以我们要引入Dao层 private UserDao userDao; public UserServiceImpl() { userDao = new UserDaoImpl(); } @Override public User login(String userCode, String password) { Connection connection = null; User user = null; try { connection = BaseDao.getConnection(); //通过业务层调用对应的数据库操作 user = userDao.getLoginUser(connection, userCode); } catch (SQLException e) { e.printStackTrace(); } finally { BaseDao.closeResource(connection, null, null); } return user; }
编写Servlet
package com.hitenine.servlet.user; import com.hitenine.pojo.User; import com.hitenine.service.user.UserServiceImpl; import com.hitenine.util.Constants; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; public class LoginServlet extends HttpServlet { //Servlet:控制层,调用业务层 @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { System.out.println("LoginServlet---start---"); //获取用户名和密码 String userCode = req.getParameter("userCode"); String userPassword = req.getParameter("userPassword"); //和数据库中的密码进行对比,调用业务层 UserServiceImpl userService = new UserServiceImpl(); User user = userService.login(userCode, userPassword); //这里已经把登录的人给查出来了 //判断语句加上user.getUserPassword().equals(userPassword),为了便于测试暂不加 if (null != user) { //查有此人,可以登录 //将用户的信息放到Session中 req.getSession().setAttribute(Constants.USER_SESSION, user); //跳转到内部主页 resp.sendRedirect("jsp/frame.jsp"); } else { //查无此人,无法登录 //转发会登陆页面,顺带提示用户名或者密码错误 req.setAttribute("error", "用户名或者密码不正确"); req.getRequestDispatcher("login.jsp").forward(req, resp); } } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { doGet(req, resp); } }
注册Servlet
<!--Servlet--> <servlet> <servlet-name>LoginServlet</servlet-name> <servlet-class>com.hitenine.servlet.user.LoginServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>LoginServlet</servlet-name> <url-pattern>/login.do</url-pattern> </servlet-mapping>
测试访问,确保以上功能成功!
登录功能优化
注销功能
思路:移除Session,返回登陆页面
package com.hitenine.servlet.user;
import com.hitenine.util.Constants;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class LogoutServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//移除用户的Constants.USER_SESSION
req.getSession().removeAttribute(Constants.USER_SESSION);
resp.sendRedirect(req.getContextPath() + "/login.jsp"); //返回登录页面
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req, resp);
}
}
注册xml
<servlet>
<servlet-name>LogoutServlet</servlet-name>
<servlet-class>com.hitenine.servlet.user.LogoutServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LogoutServlet</servlet-name>
<url-pattern>/jsp/logout.do</url-pattern>
</servlet-mapping>
登录拦截优化
package com.hitenine.filter;
import com.hitenine.pojo.User;
import com.hitenine.util.Constants;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
public class SysFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
HttpServletRequest req = (HttpServletRequest) request;
HttpServletResponse resp = (HttpServletResponse) response;
User user = (User) req.getSession().getAttribute(Constants.USER_SESSION);
if (null == user) { //已经被移除或者注销了,或者未登录
resp.sendRedirect("/smbms/error.jsp");
} else {
chain.doFilter(request, response);
}
}
@Override
public void destroy() {
}
}
注册xml
<!--用户登录过滤器-->
<filter>
<filter-name>SysFilter</filter-name>
<filter-class>com.hitenine.filter.SysFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>SysFilter</filter-name>
<url-pattern>/jsp/*</url-pattern>
</filter-mapping>
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