javaWeb|Javaweb菜单信息管理的一级菜单和二级菜单显示 java|sql|数据库

对于?个系统??，系统功能是由程序员进?开发和实现的，菜单相对?较固定的；如果要新增?个菜单，则需要有对应的功能?撑，因此对于菜单的添加操作不会让管理员来实现，?是由程序员实现的。因此菜单信息管理功能主要就是对菜单的展示。
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数据库操作代码实现查询所有的?级菜单查询所有的?级菜单根据?级菜单查询所有的?级菜单 1. 涉及数据表菜单信息表tb_menus2.SQL 指令-- 1查询所有?级菜单selectmenu_id,menu_code,menu_name,menu_order,menu_level,menu_iconfromtb_menuswheremenu_level = 1order bymenu_order; -- 2查询所有的?级菜单selectmenu_id,menu_code,menu_name,menu_order,menu_level,parent_menu_code,menu_urlfromtb_menuswheremenu_level = 2order bymenu_order; -- 3根据?级菜单 code 查询当前?级菜单下的?级菜单selectmenu_id,menu_code,menu_name,menu_order,menu_level,parent_menu_code,menu_urlfromtb_menuswhereparent_menu_code = '01'order bymenu_order; 3. 在 MenuDAO 类中实现数据库操作

package com.it.dao; import com.it.entity.Menu1; import com.it.entity.Menu2; import com.it.untils.DruidUtils; import org.apache.commons.dbutils.QueryRunner; import org.apache.commons.dbutils.handlers.BeanListHandler; import javax.sql.DataSource; import java.sql.Array; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; //实现菜单的查询 public class MenuDAO { //根据管理员ID查询对应的一级菜单 public List selectFirstLevelMenusById(String mgrId) throws SQLException { List menu1List = new ArrayList<>(); String str="SELECT c.menu_id menuId,menu_code menuCode,menu_name menuName,menu_order menuOrder,menu_level menuLevel,menu_icon menuIcon FROM tb_mgr_role a " + "INNER JOIN tb_role_menu b INNER JOIN tb_menus c ON a.role_id=b.role_id AND b.menu_id=c.menu_id WHERE a.mgr_id=? AND menu_level=1 ORDER BY c.menu_order"; QueryRunner queryRunner = new QueryRunner(DruidUtils.getDataSource()); menu1List= queryRunner.query(str, new BeanListHandler(Menu1.class), mgrId); return menu1List; } //根据管理员ID和一级菜单ID，查询当前一级菜单所拥有的二级菜单 public List selectSecondLevelMenusByIdAndParentCode(String mgrId,String parentCode) throws SQLException { List menu2List = new ArrayList<>(); String sql="SELECT c.menu_id menuId,menu_code menuCode,menu_name menuName,menu_order menuOrder,menu_level menuLevel,parent_menu_code parentMenuCode,menu_url menuUrl FROM tb_mgr_role a " + "INNER JOIN tb_role_menu b INNER JOIN tb_menus c ON a.role_id=b.role_id AND b.menu_id=c.menu_id WHERE a.mgr_id=? AND menu_level=2 AND parent_menu_code=? ORDER BY c.menu_order"; QueryRunner queryRunner = new QueryRunner(DruidUtils.getDataSource()); menu2List=queryRunner.query(sql,new BeanListHandler(Menu2.class),mgrId,parentCode); return menu2List; }//查询所有的一级菜单 public List selectMenu1() throws SQLException { Listmenu1List = new ArrayList<>(); String sql="SELECT menu_id menuId,menu_code menuCode,menu_name menuName,menu_order menuOrder,menu_level menuLevel,menu_icon menuIcon FROM tb_menus WHERE menu_level=1 ORDER BY menu_order"; QueryRunner queryRunner=new QueryRunner(DruidUtils.getDataSource()); menu1List= queryRunner.query(sql, new BeanListHandler(Menu1.class)); returnmenu1List; } //查询所有的二级菜单 public List selectMenu2() throws SQLException { List menu2List=new ArrayList<>(); String sql="SELECT menu_id menuId,menu_code menuCode,menu_name menuName,menu_order menuOrder,menu_level menuLevel,parent_menu_code parentMenuCode,menu_url menuUrl FROM tb_menus WHERE menu_level=2 ORDER BY menu_code "; QueryRunner queryRunner = new QueryRunner(DruidUtils.getDataSource()); menu2List = queryRunner.query(sql, new BeanListHandler(Menu2.class)); return menu2List; } //查询某一级菜单所拥有的二级菜单 public List selectMenu2ByMenu1Code(String parentMenuCode) throws SQLException { List menu2List=new ArrayList<>(); String sql="SELECT menu_id menuId,menu_code menuCode,menu_name menuName,menu_order menuOrder,menu_level menuLevel,parent_menu_code parentMenuCode,menu_url menuUrl FROM tb_menus " + "WHERE parent_menu_code=? AND menu_level=2 ORDER BY menu_code; "; QueryRunner queryRunner = new QueryRunner(DruidUtils.getDataSource()); menu2List= queryRunner.query(sql, new BeanListHandler(Menu2.class), parentMenuCode); return menu2List; } }

4业务逻辑层代码实现在 MenuService 中实现两个业务查询所有?级菜单和?级菜单根据?级菜单查询?级菜单

package com.it.service; import com.it.dao.MenuDAO; import com.it.entity.Menu1; import com.it.entity.Menu2; import java.sql.SQLException; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; public class MenuService { public List selectMenuByMgrId(String mgrId) throws SQLException { MenuDAO menuDAO = new MenuDAO(); //根据管理员ID查询该管理员的一级菜单 List menu1List = menuDAO.selectFirstLevelMenusById(mgrId); //查询每一个一级菜单中的二级菜单 for (int i = 0; i < menu1List.size(); i++) { Menu1 menu1 = menu1List.get(i); List menu2s = menuDAO.selectSecondLevelMenusByIdAndParentCode(mgrId, menu1.getMenuCode()); menu1.setChildMenus(menu2s); } return menu1List; } //查询所有的一级二级菜单 public Map listMenus() throws SQLException { Map mapMenus = new HashMap<>(); MenuDAO menuDAO = new MenuDAO(); List menu1List = menuDAO.selectMenu1(); List menu2List = menuDAO.selectMenu2(); mapMenus.put("menu1List",menu1List); mapMenus.put("menu2List",menu2List); return mapMenus; } //查询某个一级菜单所拥有的二级菜单 public List selectMenu2ByMenu1Code(String menu1Code) throws SQLException { List menu2List = new ArrayList<>(); MenuDAO menuDAO = new MenuDAO(); menu2List = menuDAO.selectMenu2ByMenu1Code(menu1Code); return menu2List; } }

5创建MenuListServlet类

package com.it.servlets; import com.it.service.MenuService; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.sql.SQLException; import java.util.List; import java.util.Map; @WebServlet("/MenuListServlet") public class MenuListServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { doPost(req,resp); }@Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { MenuService menuService = new MenuService(); try { Map map = menuService.listMenus(); req.setAttribute("menu1List",map.get("menu1List")); req.setAttribute("menu2List",map.get("menu2List")); req.getRequestDispatcher("admin_menu_list.jsp").forward(req,resp); } catch (SQLException e) { e.printStackTrace(); }} }

6.在admin_menu_list.jsp使? JSTL+EL 显示菜单信息

管理员一级菜单列表全部管理员（13） ${menu1.menuName} 菜单编号菜单名称菜单排序菜单级别菜单编号菜单URL 状态操作 ${menu2.menuCode} ${menu2.menuName} ${menu2.menuOrder} ${menu2.menuLevel} ${menu2.parentMenuCode} ${menu2.menuUrl} 已启用 *管理员：*初始密码：*确认密码：*性别：保密男女*手机：*邮箱：角色：备注：剩余字数：100字