Javaweb teaching system project practical permission management module

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mission target

• Business goal:
  Understand the implementation logic of permission management

• Skill target
  code to implement role management and personnel management

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Involving knowledge points

1. SQL language and basic operations

2. JDBC (Java Database Connection)

3. Use of custom tool classes and properties configuration files

4. JDBC connection pool

5. Enumeration class definition

6. Servlet processes requests ( Servlet working principle , Servlet request and response )

7. JSTL tag library + EL expression

8、JSP

9. AJAX learning

10、HTML、CSS

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Task process

1. Familiar with the functions of the permission module
2. Understand the data tables involved in the permission module
3. Implement user list display
4. Implement the addition, deletion, modification and checking of roles
5. Implement dynamic display of permission menu

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Ideas and code implementation

This module is based on the student management module, so for part of the code (that is, the code with the white title in the file), please refer to the article Javaweb Teaching System Project Practical Student Management Module

The following code is based on the previous article

☆Front-end page creation

Menus, roles and users, each corresponding list, addition and modification

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☆Database creation

Create a database, and create the menu information table menu , the role information table role , the login user information table users and the intermediate table connecting role and menu.

menu

role

users

middle

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☆Backend

1. Toolkit utils

For details, see the article Javaweb Teaching System Project Practical Student Management Module

Create a utils package, create a new class DBUtils, and create a new configuration file db.properties

properties configuration file

Use ResourceBundle to access local resources and read the values ​​we need from them

DBUtils

JDBC tool class encapsulates methods for operating sql, so static methods are recommended.

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2. Definition of entity classes and creation of bean packages

The file with the white file title already exists

For details, see the article Javaweb Teaching System Project Practical Student Management Module

Create the corresponding class based on the created sql.
Class name = table name, attribute name = column name.

Menu

• Define properties

    private Integer menuId;
    private String menuName;
    private Integer upmenuId;
    private Integer state;
    private String desc;
    private String url;

    /**
     * 和role多对多
     */
    private List<Role> roleList;

    /**
     * 保存二级目录
     */
    private List<Menu> secondMenuList;

• Setting and getting values ​​with setters and getters

    public Integer getMenuId() {
    
    
        return menuId;
    }

    public void setMenuId(Integer menuId) {
    
    
        this.menuId = menuId;
    }

    public String getMenuName() {
    
    
        return menuName;
    }

    public void setMenuName(String menuName) {
    
    
        this.menuName = menuName;
    }

    public Integer getUpmenuId() {
    
    
        return upmenuId;
    }

    public void setUpmenuId(Integer upmenuId) {
    
    
        this.upmenuId = upmenuId;
    }

    public Integer getState() {
    
    
        return state;
    }

    public void setState(Integer state) {
    
    
        this.state = state;
    }

    public String getDesc(String desc) {
    
    
        return this.desc;
    }

    public void setDesc(String desc) {
    
    
        this.desc = desc;
    }

    public String getUrl() {
    
    
        return url;
    }

    public void setUrl(String url) {
    
    
        this.url = url;
    }

    public List<Role> getRoleList() {
    
    
        return roleList;
    }

    public void setRoleList(List<Role> roleList) {
    
    
        this.roleList = roleList;
    }

    public List<Menu> getSecondMenuList() {
    
    
        return secondMenuList;
    }

    public void setSecondMenuList(List<Menu> secondMenuList) {
    
    
        this.secondMenuList = secondMenuList;
    }

Role

• Define properties

    private Integer roleId;
    private String roleName;
    private Integer roleState;

    /**
     * 一个角色包含多个用户
     */
    private List<Users> usersList;
    private List<Menu> menuList;

• Setting and getting values ​​with setters and getters

	public Integer getRoleId() {
    
    
        return roleId;
    }

    public void setRoleId(Integer roleId) {
    
    
        this.roleId = roleId;
    }

    public String getRoleName() {
    
    
        return roleName;
    }

    public void setRoleName(String roleName) {
    
    
        this.roleName = roleName;
    }

    public Integer getRoleState() {
    
    
        return roleState;
    }

    public void setRoleState(Integer roleState) {
    
    
        this.roleState = roleState;
    }

    public List<Users> getUsersList() {
    
    
        return usersList;
    }

    public void setUsersList(List<Users> usersList) {
    
    
        this.usersList = usersList;
    }

    public List<Menu> getMenuList() {
    
    
        return menuList;
    }

    public void setMenuList(List<Menu> menuList) {
    
    
        this.menuList = menuList;
    }

Users

• Define properties

    private Integer userId;
    private String loginName;
    private String password;
    private String realName;
    private Integer sex;
    private String email;
    private String address;
    private String phone;
    private String cardId;
    private String desc;
    private Integer roleId;
     /**
     * 一个用户包含一个角色
     * @return
     */
    private Role role;

• Setting and getting values ​​with setters and getters

    public Integer getUserId() {
    
    
        return userId;
    }

    public void setUserId(Integer userId) {
    
    
        this.userId = userId;
    }

    public String getLoginName() {
    
    
        return loginName;
    }

    public void setLoginName(String loginName) {
    
    
        this.loginName = loginName;
    }

    public String getPassword() {
    
    
        return password;
    }

    public void setPassword(String password) {
    
    
        this.password = password;
    }

    public String getRealName() {
    
    
        return realName;
    }

    public void setRealName(String realName) {
    
    
        this.realName = realName;
    }

    public Integer getSex() {
    
    
        return sex;
    }

    public void setSex(Integer sex) {
    
    
        this.sex = sex;
    }

    public String getEmail() {
    
    
        return email;
    }

    public void setEmail(String email) {
    
    
        this.email = email;
    }

    public String getAddress() {
    
    
        return address;
    }

    public void setAddress(String address) {
    
    
        this.address = address;
    }

    public String getPhone() {
    
    
        return phone;
    }

    public void setPhone(String phone) {
    
    
        this.phone = phone;
    }

    public String getCardId() {
    
    
        return cardId;
    }

    public void setCardId(String cardId) {
    
    
        this.cardId = cardId;
    }

    public String getDesc() {
    
    
        return desc;
    }

    public void setDesc(String desc) {
    
    
        this.desc = desc;
    }

    public Integer getRoleId() {
    
    
        return roleId;
    }

    public void setRoleId(Integer roleId) {
    
    
        this.roleId = roleId;
    }

    public Role getRole() {
    
    
        return role;
    }

    public void setRole(Role role) {
    
    
        this.role = role;
    }

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3. Implementation of module functions

The file with the white file title already exists

For details, see the article Javaweb Teaching System Project Practical Student Management Module

Various operations of student management are defined in the service package

The dao layer defines the specific implementation of service layer operations.

Define servlet in web package

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※ Users

Realize user login and logout, user list display

UsersService(Impl)、UsersDao(Impl)、UsersServlet

① User login

Implement dynamic permission list display when logging in

service

UsersService

    /**
     * 登录方法
     */
    public Users login(String username,String password);

UsersServiceImpl

    /**
     * 登录方法
     * @param username
     * @param password
     * @return
     */
    @Override
    public Users login(String username, String password) {
    
    
        Users users = usersDao.login(username, password);

        if(users == null){
    
    
            return null;
        }
        //如果非空，根据角色id查询角色菜单信息（角色名称、菜单名、请求地址。。。三表联查）
        Integer roleId = users.getRoleId();
        //定义一个方法，查询角色信息
        Role role = roleDao.findById(roleId);
        //当前角色没有进行菜单分类，即没有一二级，因此对菜单进行分级
        List<Menu> menuList = role.getMenuList();
        List<Menu> newMenuList = new ArrayList<>();
        for (Menu menu:menuList) {
    
    
            if(menu.getUpmenuId()==0){
    
    //一级菜单

                ArrayList<Menu> secondList = new ArrayList<>();//用于保存二级菜单
                for (Menu second : menuList) {
    
    //跑二级菜单
                    if(second.getUpmenuId()==menu.getMenuId()){
    
    
                        secondList.add(second);
                    }
                }
                menu.setSecondMenuList(secondList);
                newMenuList.add(menu);
            }
        }
        role.setMenuList(newMenuList);//把分级之后的菜单保存到role中
        users.setRole(role);
        return users;
    }

dao

UsersDao

    /**
     * 登录方法
     */
    public Users login(String username, String password);

UsersDaoImpl

    /**
     * 登录方法
     * @param username
     * @param password
     * @return
     */
    @Override
    public Users login(String username, String password) {
    
    
        Users users = null;
        try {
    
    
            String sql = "select * from users where loginname = ? and password = ?";
            ArrayList arrayList = new ArrayList();
            arrayList.add(username);
            arrayList.add(password);
            resultSet = query(sql, arrayList);//查询之后返回结果集
            //包装结果集数据
            users = null;
            if(resultSet == null){
    
    
                return null;
            }
            while (resultSet.next()){
    
    
                users = new Users();
                users.setLoginName(username);
                users.setRealName(resultSet.getString("realname"));
                users.setUserId(resultSet.getInt("userid"));
                users.setRoleId(resultSet.getInt("roleid"));
            }
        } catch (SQLException throwables) {
    
    
            throwables.printStackTrace();
        } finally {
    
    
            closeAll();
        }
        return users;
    }

servlet

LoginServlet

In the login.jsp page, enter username and password and click the login button to submit the form.action=“login” method=“post”

@WebServlet(urlPatterns = "/login")
public class LoginServlet extends HttpServlet {
    
    
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    
    
        //1.接收参数
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        //2.调取service
        UsersService usersService = new UsersServiceImpl();
        Users users = usersService.login(username, password);
        //3.跳转页面
        if(users == null){
    
    
            //以弹窗方式提示用户，登录失败
            resp.setContentType("text/html;charset=utf-8");//防止返回数据乱码
            PrintWriter writer = resp.getWriter();
            writer.println("<script>location.href='login.jsp';alert('用户名或密码不正确');</script>");
        }else{
    
    
            //保存用户信息，重定向跳转到主页面
            //session，整个会话期间
            req.getSession().setAttribute("u1",users);
            resp.sendRedirect("index.jsp");
        }
    }
}

---

② Query user list, total number of items

service

UsersService

	 /**
     * 查询总条数
     */
    public int total();

UsersServiceImpl

    @Override
    public int total() {
    
    
        return usersDao.total();
    }

dao

UsersDao

    /**
     * 查询总条数
     */
    public int total();

UsersDaoImpl

    /**
     * 统计条数
     * @return
     */
    @Override
    public int total() {
    
    
        int total = 0;
        try {
    
    
            String sql = "select count(1) from users u,role r where u.roleid = r.roleid ";
            resultSet = query(sql, null);
            while (resultSet.next()){
    
    
                total = resultSet.getInt(1);
            }
        } catch (SQLException throwables) {
    
    
            throwables.printStackTrace();
        } finally {
    
    
            closeAll();
        }
        return total;
    }

servlet

UsersServlet

    /**
     * 查询列表
     */
    protected void findlist(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    
    
        //1.2分页数据（limit 开始位置，显示条数）
        //页码值
        String pageIndex = req.getParameter("pageIndex");//当前页码值
        //如果页面没有传入pageIndex的值，则默认查询第一页
        int index = pageIndex==null?1:Integer.parseInt(pageIndex);

        //2调取service方法
        PageUtil pageUtil = new PageUtil();
        UsersService service = new UsersServiceImpl();

        /**
         * 获取总页数
         * 总页数=总条数%每页显示的条数>0?总条数/每页显示的条数+1:总条数/每页显示的条数
         */
        int total = service.total();//总条数
        pageUtil.setTotal(total);

        //3跳转页面

        //如果后台想给前台传数据，一定要在后台存值
        //req.setAttribute("stulist",students);
        pageUtil.setPageIndex(index);


        //存储页码值
        req.setAttribute("p1",pageUtil);

        //list前面如果加/表示从根目录下进行寻找
        req.getRequestDispatcher("list.jsp").forward(req,resp);//转发的方式，跳转到list.jsp
    }

---

③ Click to query data by page

service

UsersService

    /**
     * 查询用户列表
     */
    public List<Users> getUsersList(int pageIndex,int pageSize);

UsersServiceImpl

    @Override
    public List<Users> getUsersList(int pageIndex, int pageSize) {
    
    
        return usersDao.getUsersList(pageIndex, pageSize);
    }

dao

UsersDao

    /**
     * 查询用户列表
     */
    public List<Users> getUsersList(int pageIndex, int pageSize);

UsersDaoImpl

@Override
    public List<Users> getUsersList(int pageIndex, int pageSize) {
    
    
        List<Users> usersList = new ArrayList<Users>();
        try {
    
    
            String sql = "select userid,loginname,realname,rolename from users u,role r where u.roleid = r.roleid limit ?,?";
            List params = new ArrayList();
            params.add((pageIndex-1)*pageSize);
            params.add(pageSize);
            resultSet = query(sql, params);
            while (resultSet.next()){
    
    
                //1取出各表的数据
                Users users = new Users();
                users.setUserId(resultSet.getInt("userid"));
                users.setLoginName(resultSet.getString("loginname"));
                users.setRealName(resultSet.getString("realname"));

                Role role = new Role();
                role.setRoleName(resultSet.getString("rolename"));
                //2建立关系
                users.setRole(role);
                usersList.add(users);
            }
        } catch (SQLException throwables) {
    
    
            throwables.printStackTrace();
        } finally {
    
    
            closeAll();
        }
        return usersList;
    }

servlet

UsersServlet

/power/user/users?method=select

    /**
     * 查询数据
     * （分页）
     */
    protected void select(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    
    
        //1接收参数.分页参数、模糊查参数
        String index = req.getParameter("index");
        int pageIndex=(index==null || index.length()==0)?1:Integer.parseInt(index);
        //2调取service方法
        PageUtil pageUtil = new PageUtil();
        List<Users> usersList = usersService.getUsersList(pageIndex, pageUtil.getPageSize());
        int total = usersService.total();
        pageUtil.setTotal(total);//总条数
        pageUtil.setPageIndex(pageIndex);
        pageUtil.setDataList(usersList);

        //3存值跳页面
        req.setAttribute("pi",pageUtil);
        req.getRequestDispatcher("list.jsp").forward(req,resp);
    }

---

④ Add user information

service

UsersService

    /**
     * 新增用户
     */
    public int insertUser(Users users);

UsersServiceImpl

    @Override
    public int insertUser(Users users) {
    
    
        return usersDao.insertUser(users);
    }

RoleService

    /**
     * 查询角色id对应关系
     */
    public List<Role> getRoleMap();

RoleServiceImpl

    @Override
    public List<Role> getRoleMap() {
    
    
        return roleDao.getRoleMap();
    }

dao

UsersDao

    /**
     * 新增用户
     */
    public int insertUser(Users users);

UsersDaoImpl

    @Override
    public int insertUser(Users users) {
    
    
        int i = 0; 
        if(existLoginName(users.getLoginName(),users.getRealName()) == 1 || existLoginName(users.getLoginName(),users.getRealName()) == -1){
    
    
            System.out.println("该用户名已经存在！");
            return -1;
        }
        try {
    
    
            String sql = "insert into users values(null,?,?,?,?,?,?,?,?,?,?)";
            List params = new ArrayList();
            params.add(users.getLoginName());
            params.add(users.getPassword());
            params.add(users.getRealName());
            params.add(users.getSex());
            params.add(users.getEmail());
            params.add(users.getAddress());
            params.add(users.getPhone());
            params.add(users.getCardId());
            params.add(users.getDesc());
            params.add(users.getRoleId());

            i = update(sql, params);//i表示受影响的行数
        } catch (Exception e) {
    
    
            e.printStackTrace();
        } finally {
    
    
            closeAll();
        }
        return i;
    }


	/**
     *根据用户名判断该用户是否存在
     */
    public int existLoginName(String loginname,String realname){
    
    
        int f = 0;
        System.out.println("2判断用户名是否存在");
        System.out.println("传入的loginname："+loginname+"-realname:"+realname);
        Users users = findByName(realname);
        System.out.println("2:  此时传入根据姓名查找用户名的user,"+"此时users：loginname:"+users.getLoginName()+"-realname:"+users.getRealName());
        if(loginname.equals(users.getLoginName())){
    
    
            System.out.println("此时该用户名存在");
            return -1;
        }
        try {
    
    
            String sql = "select * from users where loginname = ?";
            List params = new ArrayList();
            params.add(loginname);
            resultSet = query(sql, params);
            if(resultSet.next()) {
    
    
                f = 1;
            }
        } catch (SQLException throwables) {
    
    
            throwables.printStackTrace();
        } finally {
    
    
            closeAll();
        }
        return f;
    }

    /**
     * 通过姓名查找用户名是否存在
     * @return
     */
    public Users findByName(String realname) {
    
    
        System.out.println("3执行findByName");
        Users users = new Users();
        try {
    
    
            String sql = "select * from users where realname = ?";
            List params = new ArrayList();
            params.add(realname);
            resultSet = query(sql, params);
            System.out.println("传进来的realname："+realname);
            //System.out.println("finebyname resultSet:");
            while(resultSet.next()){
    
    
                //目前只需要获得登录名和姓名，因此其它省略
                users.setLoginName(resultSet.getString("loginname"));
                System.out.println("loginname:"+resultSet.getString("loginname"));
                users.setRealName(resultSet.getString("realname"));
                System.out.println("realname:"+resultSet.getString("realname"));
                System.out.println("此时users：loginname:"+users.getLoginName()+"-realname:"+users.getRealName());
            }
        } catch (SQLException throwables) {
    
    
            throwables.printStackTrace();
        } finally {
    
    
            closeAll();
        }
        return users;
    }

RoleDao

    /**
     * 查询角色id对应关系
     */
    public List<Role> getRoleMap();

RoleDaoImpl

    @Override
    public List<Role> getRoleMap() {
    
    
        List rs = new ArrayList();
        try {
    
    
            String sql = "select * from role";
            resultSet = query(sql, null);
            while (resultSet.next()){
    
    
                Role role = new Role();
                role.setRoleId(resultSet.getInt("roleid"));
                role.setRoleName(resultSet.getString("rolename"));
                rs.add(role);
            }
        } catch (SQLException throwables) {
    
    
            throwables.printStackTrace();
        } finally {
    
    
            closeAll();
        }
        return rs;
    }

servlet

RoleListServlet

Get a list of roles,href="/power/user/getRoleList"

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    
    
        RoleService service = new RoleServiceImpl();
        List<Role> list = service.getRoleMap();
        req.setAttribute("rlist",list);
        req.getRequestDispatcher("add.jsp").forward(req,resp);
    }

UsersServlet

Enter the user information in add and submit it.action="/power/role/roles?method=insert" method=“post”, continue processing in UsersServlet

    /**
     * 新增用户信息
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void insert(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    
    
        //处理乱码
        //req.setCharacterEncoding("utf-8");
        //接收参数
        String loginName = req.getParameter("loginName");
        String password = req.getParameter("password");
        String realName = req.getParameter("realName");
        String sex = req.getParameter("sex");
        String roleId = req.getParameter("roleId");
        String email = req.getParameter("email");
        String phone = req.getParameter("phone");
        String address = req.getParameter("address");
        String cardId = req.getParameter("cardId");
        String desc = req.getParameter("desc");


        //调取service方法
        UsersService service = new UsersServiceImpl();

        //将参数封装到学生对象中
        Users users = new Users();
        users.setLoginName(loginName);
        users.setPassword(password);
        users.setRealName(realName);
        users.setSex(Integer.parseInt(sex));
        users.setRoleId(Integer.parseInt(roleId));
        users.setEmail(email);
        users.setPhone(phone);
        users.setAddress(address);
        users.setCardId(cardId);
        users.setDesc(desc);

        int i = service.insertUser(users);//受影响的行数
        System.out.println("insertUser受影响的行数"+i);
        resp.setContentType("text/html;charset=utf-8");
        PrintWriter writer = resp.getWriter();

        if(i>0){
    
    //新增成功
            writer.println("<script>alert('新增成功');location.href='/power/user/users?method=select'</script>");
        }else if(i == -1){
    
    
            writer.println("<script>alert('该用户名已存在，新增失败');location.href='/power/user/getRoleList'</script>");
        }else{
    
    //新增失败
            writer.println("<script>alert('新增失败,请检查输入信息');location.href='/power/user/getRoleList'</script>");
        }
    }

---

※ Role

Add, delete, modify and check roles

RoleService(Impl)、RoleDao(Impl)、RoleServlet

① Query list

servlet

RoleServlet

    /**
     * 查询列表
     */
    protected void findlist(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    
    
        //1获取参数（两部分，第一部分：模糊从查找的条件  第二部分：分页数据）

//        //1.1模糊查找条件
//        String stuname = req.getParameter("stuname");
//        String stuno = req.getParameter("stuno");
//        String sex = req.getParameter("sex");

        //1.2分页数据（limit 开始位置，显示条数）
        //页码值
        String pageIndex = req.getParameter("pageIndex");//当前页码值
        //如果页面没有传入pageIndex的值，则默认查询第一页
        int index = pageIndex==null?1:Integer.parseInt(pageIndex);

        //2调取service方法
        PageUtil pageUtil = new PageUtil();
        UsersService service = new UsersServiceImpl();

        /**
         * 获取总页数
         * 总页数=总条数%每页显示的条数>0?总条数/每页显示的条数+1:总条数/每页显示的条数
         */
        int total = service.total();//总条数
        pageUtil.setTotal(total);

        //3跳转页面

        //如果后台想给前台传数据，一定要在后台存值
        //req.setAttribute("stulist",students);
        pageUtil.setPageIndex(index);


        //存储页码值
        req.setAttribute("p1",pageUtil);
        //list前面如果加/表示从根目录下进行寻找
        req.getRequestDispatcher("list.jsp").forward(req,resp);//转发的方式，跳转到list.jsp
    }

---

② Query all roles (pagination)

service

RoleService

    /**
     *查询所有角色
     */
    public List<Role> getRoleList(int pageIndex,int pageSize);
    
    /**
     * 查询总条数
     */
    public int total();

RoleServiceImpl

    @Override
    public List<Role> getRoleList(int pageIndex, int pageSize) {
    
    
        return roleDao.getRoleList(pageIndex, pageSize);
    }

    @Override
    public int total() {
    
    
        return roleDao.total();
    }

dao

RoleDao

    /**
     *查询所有角色
     */
    public List<Role> getRoleList(int pageIndex,int pageSize);

    /**
     * 查询总条数
     */
    public int total();

RoleDaoImpl

    @Override
    public List<Role> getRoleList(int pageIndex, int pageSize) {
    
    
        List<Role> rolesList = new ArrayList<Role>();
        try {
    
    
            String sql = "select * from role limit ?,?";
            List params = new ArrayList();
            params.add((pageIndex-1)*pageSize);
            params.add(pageSize);
            resultSet = query(sql, params);
            while (resultSet.next()){
    
    
                //1取出各表的数据
                Role role = new Role();
                role.setRoleId(resultSet.getInt("roleid"));
                role.setRoleName(resultSet.getString("rolename"));
                role.setRoleState(resultSet.getInt("rolestate"));

                rolesList.add(role);
            }
        } catch (SQLException throwables) {
    
    
            throwables.printStackTrace();
        } finally {
    
    
            closeAll();
        }
        return rolesList;
    }

    @Override
    public int total() {
    
    
        int total = 0;
        try {
    
    
            String sql = "select count(1) from role ";
            resultSet = query(sql, null);
            while (resultSet.next()){
    
    
                total = resultSet.getInt(1);
            }
        } catch (SQLException throwables) {
    
    
            throwables.printStackTrace();
        } finally {
    
    
            closeAll();
        }
        return total;
    }

servlet

RoleServlet

    /**
     * 查询数据
     * （分页）
     */
    protected void select(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    
    
        //1接收参数.分页参数、模糊查参数
        String index = req.getParameter("index");
        int pageIndex=(index==null || index.length()==0)?1:Integer.parseInt(index);
        //2调取service方法
        PageUtil pageUtil = new PageUtil();

        List<Role> roleList = roleService.getRoleList(pageIndex, pageUtil.getPageSize());
        int total = roleService.total();
        pageUtil.setTotal(total);//总条数
        pageUtil.setPageIndex(pageIndex);
        pageUtil.setDataList(roleList);

        //3存值跳页面
        req.setAttribute("pi",pageUtil);
        req.getRequestDispatcher("list.jsp").forward(req,resp);
    }

---

③ Add new characters

service

RoleService

    /**
     * 新增角色
     */
    public int insertRole(String rolename,String state,String[] ids);

RoleServiceImpl

    @Override
    public int insertRole(String rolename, String state, String[] ids) {
    
    
        /**
         * 1和2都执行成功，则新增成功
         */
        int k1 = 0;//标记
        try {
    
    
            //1新增角色表
            Role role = new Role();
            role.setRoleName(rolename);
            role.setRoleState(Integer.parseInt(state));

            int k = roleDao.insertRole(role);
            //2新增中间表
            //（获得新增数据的id）
            for (String id : ids) {
    
    
                middleDao.insertMiddle(k,Integer.parseInt(id));
            }

            k1 = 1;
        } catch (NumberFormatException e) {
    
    
            e.printStackTrace();
        }
        return k1;
    }

MenuService

    /**
     * 查询菜单列表，无参数，无分级
     */
    public List<Menu> getMenuList();

MenuServiceImpl

    @Override
    public List<Menu> getMenuList() {
    
    
        List<Menu> menuList = menuDao.getMenuList();//先调取方法返回菜单集合，此时没有分一二级
        /**
         * 进行分页
         */
        //保存分级以后的菜单
        List<Menu> newMenuList = new ArrayList<>();
        for (Menu menu:menuList) {
    
    
            if(menu.getUpmenuId()==0){
    
    //一级菜单

                ArrayList<Menu> secondList = new ArrayList<>();//用于保存二级菜单
                for (Menu second : menuList) {
    
    //跑二级菜单
                    if(second.getUpmenuId()==menu.getMenuId()){
    
    
                        secondList.add(second);
                    }
                }
                menu.setSecondMenuList(secondList);
                newMenuList.add(menu);
            }
        }
        return newMenuList;
    }

dao

RoleDao

    /**
     * 新增角色
     */
    public int insertRole(Role role);

RoleDaoImpl

    @Override
    public int insertRole(Role role) {
    
    
        int key = 0;//新增数据的id
        try {
    
    
            String sql = "insert into role values(null,?,?)";
            List params = new ArrayList();
            params.add(role.getRoleName());
            params.add(role.getRoleState());
            int update = update(sql, params);//update保存的是受影响的行数
            ResultSet generatedKeys = pps.getGeneratedKeys();
            if(generatedKeys.next()){
    
    
                key = generatedKeys.getInt(1);
            }
        } catch (Exception e) {
    
    
            e.printStackTrace();
        } finally {
    
    
            closeAll();
        }
        return key;
    }

MiddleDao

    /**
     * 新增角色
     */
    public int insertMiddle(int roleId,int menuId);

MiddleDaoImpl

@Override
    public int insertMiddle(int roleId, int menuId) {
    
    
        int i = 0;
        try {
    
    
            String sql = "insert into middle values(null,?,?)";
            List params = new ArrayList();
            params.add(roleId);
            params.add(menuId);
            i = update(sql, params);
        } catch (Exception e) {
    
    
            e.printStackTrace();
        } finally {
    
    
            closeAll();
        }
        return i;
    }

servlet

RoleServlet

First get the menu list, that is, the function list corresponding to the rolehref="/power/role/roles?method=selectmenus"

    /**
     * 查询菜单列表
     */
    protected void selectmenus(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    
    
        //1接收参数（无参数跳过）
        //2调取service方法
        List<Menu> menuList = menuService.getMenuList();
        req.setAttribute("menulist",menuList);
        req.getRequestDispatcher("add.jsp").forward(req,resp);
    }

After obtaining the menu list, enter the role information in the add.jsp interface to add a new role.action="/power/role/roles?method=insert" method=“post”

    /**
     * 新增角色
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void insert(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    
    
        //处理乱码
        //req.setCharacterEncoding("utf-8");
        //接收参数
        String rolename = req.getParameter("rolename");
        String state = req.getParameter("state");
        String[] menuids = req.getParameterValues("menuid");

        //调取service方法
        int i = roleService.insertRole(rolename, state, menuids);

        resp.setContentType("text/html;charset=utf-8");
        PrintWriter writer = resp.getWriter();

        if(i>0){
    
    //新增成功
            writer.println("<script>alert('新增成功');location.href='/power/role/roles?method=select'</script>");
        }else{
    
    //新增失败
            writer.println("<script>alert('新增失败,请检查输入信息');location.href='/power/role/roles?method=selectmenus'</script>");
        }

    }

---

④ Primary key query

Query role information based on id

service

RoleService

    /**
     * 根据id查找角色
     */
    public Role findById(int roleid);

RoleServiceImpl

    @Override
    public Role findById(int roleid) {
    
    
        Role role = roleDao.findById(roleid);
        return role;
    }

MenuService

    /**
     * 获取菜单列表(菜单对象里存有拥有该菜单的角色列表)
     */
    public List<Menu> getMenuList(Role role);

MenuServiceImpl

    @Override
    public List<Menu> getMenuList(Role role) {
    
    
        List<Menu> menuList = menuDao.getMenuList();//未分级
        //1.遍历集合，将role赋值
        for (Menu menu : menuList) {
    
    
            for (Menu roleMenu : role.getMenuList()) {
    
    
                if(menu.getMenuId() == roleMenu.getMenuId()){
    
    
                    List<Role> list = new ArrayList<>();
                    list.add(role);
                    menu.setRoleList(list);
                }
            }
        }
        //2.分级
        List<Menu> newMenuList = new ArrayList<>();
        for (Menu menu : menuList) {
    
    
            if(menu.getUpmenuId() == 0){
    
    
                List<Menu> secondList = new ArrayList<>();
                for (Menu second : menuList) {
    
    
                    if(second.getUpmenuId() == menu.getMenuId()){
    
    
                        secondList.add(second);
                    }
                }
                menu.setSecondMenuList(secondList);
                newMenuList.add(menu);
            }
        }
        return newMenuList;
    }

dao

RoleDao

    /**
     * 根据id查找角色
     */
    public Role findById(int roleid);

RoleDaoImpl

    @Override
    public Role findById(int roleid) {
    
    
        Role role = new Role();
        ArrayList<Menu> ms = new ArrayList<>();
        try {
    
    
            String sql ="select * from role,middle,menu where role.roleid = middle.roleid and middle.menuid = menu.menuid and role.roleid = ?";
            List params = new ArrayList();
            params.add(roleid);

            resultSet = query(sql,params);
            while (resultSet.next()){
    
    
                role.setRoleId(resultSet.getInt("roleid"));
                role.setRoleName(resultSet.getString("rolename"));
                role.setRoleState(resultSet.getInt("rolestate"));

                Menu menu = new Menu();
                menu.setMenuId(resultSet.getInt("menuid"));
                menu.setMenuName(resultSet.getString("menuname"));
                menu.setUrl(resultSet.getString("url"));
                menu.setState(resultSet.getInt("state"));
                menu.setUpmenuId(resultSet.getInt("upmenuid"));
                ms.add(menu);
            }
            role.setMenuList(ms);
        } catch (SQLException throwables) {
    
    
            throwables.printStackTrace();
        } finally {
    
    
            closeAll();
        }
        return role;
    }

MenuDao

    /**
     * 查询菜单列表
     */
    public List<Menu> getMenuList();

MenuDaoImpl

    @Override
    public List<Menu> getMenuList() {
    
    
        List<Menu> menuList = new ArrayList<>();
        try {
    
    
            String sql = "select * from menu";
            resultSet = query(sql, null);
            while (resultSet.next()){
    
    
                Menu menu = new Menu();
                menu.setMenuId(resultSet.getInt("menuid"));
                menu.setMenuName(resultSet.getString("menuname"));
                menu.setUpmenuId(resultSet.getInt("upmenuid"));
                menu.setState(resultSet.getInt("state"));
                menu.setDesc(resultSet.getString("desc"));
                menu.setUrl(resultSet.getString("url"));
                menuList.add(menu);
            }
        } catch (SQLException throwables) {
    
    
            throwables.printStackTrace();
        } finally {
    
    
            closeAll();
        }
        return menuList;
    }

servlet

RoleServlet

href="/power/role/roles?method=findbyid&roleid=${r.roleId}"

    /**
     * 主键查询
     */
    protected void findbyid(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    
    
        //1接收参数
        String roleId = req.getParameter("roleid");
        //2处理查询方法,根据主键查询学生信息
        Role role = roleService.findById(Integer.parseInt(roleId));
        List<Menu> menuList = menuService.getMenuList(role);

        req.setAttribute("role",role);
        req.setAttribute("menulist",menuList);
        req.getRequestDispatcher("edit.jsp").forward(req,resp);

    }

---

⑤ Modify role

service

RoleService

    /**
     * 更新角色
     */
    public int updateRole(String rolename, String state,String[] ids, String roleid);

RoleServiceImpl

    @Override
    public int updateRole(String rolename, String state,String[] ids, String roleid) {
    
    
        Role role = new Role();
        role.setRoleId(Integer.parseInt(roleid));
        role.setRoleName(rolename);
        role.setRoleState(Integer.parseInt(state));
        int update = roleDao.updateRole(role);
        System.out.println("RoleServiceIimpl-role-Id:"+role.getRoleId());
        int delete = middleDao.deleteMiddle(Integer.parseInt(roleid));

        //新增middle表
        int count = 0;
        for (String menu : ids) {
    
    
            count += middleDao.insertMiddle(Integer.parseInt(roleid), Integer.parseInt(menu));
        }
        return count;
    }

dao

RoleDao

    /**
     * 更新角色
     */
    public int updateRole(Role role);

RoleDaoImpl

    @Override
    public int updateRole(Role role) {
    
    
        int update = 0;
        try {
    
    
            String sql = "update role set rolename=?,rolestate=? where roleid=?";
            List params = new ArrayList();
            params.add(role.getRoleName());
            params.add(role.getRoleState());
            params.add(role.getRoleId());
            update = update(sql,params);
        } catch (Exception e) {
    
    
            e.printStackTrace();
        } finally {
    
    
            closeAll();
        }
        return update;
    }

MiddleDao

    /**
     * 更新时先将原来的id删掉
     */
    public int deleteMiddle(int roleId);

MiddleDaoImpl

    @Override
    public int deleteMiddle(int roleId) {
    
    
        int delete = 0;
        try {
    
    
            String sql = "delete from middle where roleid=? ";
            List params = new ArrayList();
            params.add(roleId);
            delete = update(sql,params);
        } catch (Exception e) {
    
    
            e.printStackTrace();
        } finally {
    
    
            closeAll();
        }
        return delete;
    }

servlet

RoleServlet

First, find the role information by performing a primary key query on the id of the role to be modified.href="/power/role/roles?method=findbyid&roleid=${r.roleId}", and then jump to the edit.jsp page to modify the information.

After modifying the information, click Submitaction="/power/role/roles?method=update" method=“post”

    /**
     * 修改角色信息
     */
    protected void update(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    
    
        //处理乱码
        //req.setCharacterEncoding("utf-8");
        //接收参数
        String roleid = req.getParameter("roleid");       
        String rolename = req.getParameter("rolename");        
        String state = req.getParameter("state");        
        String[] menuids = req.getParameterValues("menuid");
	     //调取service方法
        int i = roleService.updateRole(rolename,state,menuids,roleid);//成功count

        resp.setContentType("text/html;charset=utf-8");
        PrintWriter writer = resp.getWriter();

        if(i == menuids.length){
    
    //修改成功
            writer.println("<script>alert('修改成功');location.href='/power/role/roles?method=select'</script>");
        }else{
    
    //修改失败
            writer.println("<script>alert('修改失败,请检查输入信息');location.href='/power/role/roles?method=findbyid&roleid="+Integer.parseInt(roleid)+"'</script>");
        }
    }

---

⑥ Delete role

service

RoleService

    /**
     * 删除角色
     */
    public int deletebyid(String roleid);

RoleServiceImpl

    @Override
    public int deletebyid(String roleid) {
    
    
        int deleteMiddle = middleDao.delete(Integer.parseInt(roleid));
        int deleteRole = roleDao.deleteRole(Integer.parseInt(roleid));
        if(deleteRole>0 && deleteMiddle>0){
    
    
            return 1;
        }
        return 0;
    }

dao

RoleDao

    /**
     * 删除角色
     */
    public int deleteRole(int roleid);

RoleDaoImpl

    @Override
    public int deleteRole(int roleid) {
    
    
        int i = 0;
        try {
    
    
            String sql = "delete from role where roleid=? ";
            List params = new ArrayList();
            params.add(roleid);
            i = update(sql,params);
        } catch (Exception e) {
    
    
            e.printStackTrace();
        } finally {
    
    
            closeAll();
        }
        return i;
    }

MiddleDao

    /**
     * 删除
     */
    public int delete(int roleid);

MiddleDaoImpl

    /**
     * 删除
     */
    @Override
    public int delete(int roleid) {
    
    
        int i = 0;
        try {
    
    
            String sql = "delete from middle where roleid=? ";
            List params = new ArrayList();
            params.add(roleid);
            i = update(sql,params);
        } catch (Exception e) {
    
    
            e.printStackTrace();
        } finally {
    
    
            closeAll();
        }
        return i;
    }

servlet

RoleServlet

    /**
     * 删除角色
     */
    protected void delete(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    
    
        //处理乱码
        //req.setCharacterEncoding("utf-8");
        //接收参数
        String roleid = req.getParameter("roleid");


        //调取service方法
        int i = roleService.deletebyid(roleid);//成功返回1，失败返回0

        resp.setContentType("text/html;charset=utf-8");
        PrintWriter writer = resp.getWriter();

        if(i>0){
    
    //删除成功
            writer.println("<script>alert('删除成功');location.href='/power/role/roles?method=select'</script>");
        }else{
    
    //删除失败
            writer.println("<script>alert('删除失败');location.href='/power/role/roles?method=select'</script>");
        }
    }

---