超适合练手的一套JavaWeb项目 （超市后台管理系统）_luckyshop后台管理系统后台代码

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import java.io.IOException; public class LoginServlet extends HttpServlet {

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    String userCode = req.getParameter("userCode");
    String userPassword = req.getParameter("userPassword");

    UserService userService = new UserServiceImpl();
    User user = userService.login(userCode, userPassword);

    if(user != null){
        req.getSession().setAttribute(Constants.USER_SESSION,user);
        resp.sendRedirect("jsp/frame.jsp");
    }else{
        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);
}

}


### 8.注册servlet


xml代码
LoginServlet com.syj.servlet.LoginServlet LoginServlet /login.do 

### 9.测试访问确保以上功能成功



## 三、登陆功能优化



### 注销功能：


思路：移除Session,返回登录界面  
 java servlet代码

package com.syj.servlet; import com.syj.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 { req.getSession().removeAttribute(Constants.USER_SESSION); resp.sendRedirect("/login.jsp"); }

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    doGet(req, resp);
}

}


xml 代码




<servlet>
    <servlet-name>LogoutServlet</servlet-name>
    <servlet-class>com.syj.servlet.LogoutServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>LogoutServlet</servlet-name>
    <url-pattern>/jsp/logout.do</url-pattern>
</servlet-mapping>


## 四、登录拦截优化



### 编写一个过滤器并注册


java 代码

package com.syj.filter;

import com.syj.entity.User; import com.syj.util.Constants;

import javax.servlet.*; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException;

public class SysFilter implements Filter { public void init(FilterConfig filterConfig) throws ServletException {

}

public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IOException, ServletException {
    HttpServletRequest request = (HttpServletRequest) req;
    HttpServletResponse response = (HttpServletResponse) resp;

    User user = (User) request.getSession().getAttribute(Constants.USER_SESSION);

    if(user==null){
        response.sendRedirect("/smbms/error.jsp");
    }else{
        chain.doFilter(req,resp);
    }


}

public void destroy() {

}

}


xml 代码




<filter>
    <filter-name>SysFilter</filter-name>
    <filter-class>com.syj.filter.SysFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>SysFilter</filter-name>
    <url-pattern>/jsp/*</url-pattern>
</filter-mapping>


测试，登录，注销，权限，以上功能都要保证执行成功



## 五、密码修改



### 1.导入前端素材


pwdmodify.jsp




> 

> <li.><a.href=“${pageContext.request.contextPath }/jsp/pwdmodify.jsp”>密码修改</li.>

> 

> 

> 




### 2.写项目，建议从底层向上写



### 3.UserDao接口

//修改用户密码 public int updatePwd(Connection connection,int id,int password) throws SQLException;


### 4.UserDao接口实现类

//修改用户密码 public int updatePwd(Connection connection, int id, int password) throws SQLException { PreparedStatement pstm = null; int execute = 0; if(connection != null){ String sql = "update smbms_user set userPassword = ? where id = ?"; Object[] params = {password,id}; execute = BaseDao.execute(connection,pstm,sql,params); BaseDao.closeResource(null,pstm,null); }

    return execute;
}


### 5.UserService层

//根据用户Id修改密码 public boolean updatePwd(int id,int pwd);


### 6.UserService实现类

public boolean updatePwd(int id, int pwd) { Connection connection = null; boolean flag = false; //修改密码 try { connection = BaseDao.getConnection(); if(userDao.updatePwd(connection,id,pwd) > 0){ flag = true; } } catch (SQLException e) { e.printStackTrace(); }finally { BaseDao.closeResource(connection,null,null); } return false; }


### 7. servlet控制器层


记得实现复用，需要提取方法

@Override package com.mario.servlet;

import com.mario.entity.User; import com.mario.service.user.UserService; import com.mario.service.user.UserServiceImpl; import com.mario.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 UserServlet extends HttpServlet {

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    String method = req.getParameter("method");
    if(method.equals("savepwd") && method != null){
        this.updatePwd(req,resp);
    }
}

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    doGet(req, resp);
}

public void updatePwd(HttpServletRequest req, HttpServletResponse resp){
    Object obj = req.getSession().getAttribute(Constants.USER_SESSION);
    String newpassword = req.getParameter("newpassword");

    System.out.println(newpassword);

    boolean flag = false;

    if(obj != null && newpassword != null){
        UserService userService = new UserServiceImpl();
        flag = userService.updatePwd(((User) obj).getId(), newpassword);
        if(flag){
            req.setAttribute("message","修改密码成功");
            req.getSession().removeAttribute(Constants.USER_SESSION);
        }else{
            req.setAttribute("message","密码修改失败");
        }
    }else{
        req.setAttribute("message","新密码有问题");
    }
    try {
        req.getRequestDispatcher("pwdmodify.jsp").forward(req,resp);
    } catch (ServletException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

}


### 8. 测试



### 优化密码修改使用Ajax



### 1.阿里巴巴的fastjson


pom.xml
com.alibaba fastjson 1.2.61 

### 2.后台修改的代码

package com.mario.servlet; import com.alibaba.fastjson.JSONArray; import com.mario.entity.User; import com.mario.service.user.UserService; import com.mario.service.user.UserServiceImpl; import com.mario.util.Constants; import com.mysql.jdbc.StringUtils; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.io.PrintWriter; import java.util.HashMap; import java.util.Map;

public class UserServlet extends HttpServlet {

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    String method = req.getParameter("method");
    if(method.equals("savepwd") && method != null){
        this.updatePwd(req,resp);
    }else if(method.equals("pwdmodify") && method != null){
        this.pwdModify(req,resp);
    }
}

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    doGet(req, resp);
}

//修改密码
public void updatePwd(HttpServletRequest req, HttpServletResponse resp){
    Object obj = req.getSession().getAttribute(Constants.USER_SESSION);
    String newpassword = req.getParameter("newpassword");

    System.out.println(newpassword);

    boolean flag = false;

    if(obj != null && newpassword != null){
        UserService userService = new UserServiceImpl();
        flag = userService.updatePwd(((User) obj).getId(), newpassword);
        if(flag){
            req.setAttribute("message","修改密码成功");
            req.getSession().removeAttribute(Constants.USER_SESSION);
        }else{
            req.setAttribute("message","密码修改失败");
        }
    }else{
        req.setAttribute("message","新密码有问题");
    }
    try {
        req.getRequestDispatcher("pwdmodify.jsp").forward(req,resp);
    } catch (ServletException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

//验证旧密码,session中有用户的密码
public void pwdModify(HttpServletRequest req, HttpServletResponse resp){
    Object obj = req.getSession().getAttribute(Constants.USER_SESSION);
    String oldpassword = req.getParameter("oldpassword");

    Map<String, String> resultMap = new HashMap<String, String>();

    if(obj==null){
        resultMap.put("result","sessionerror");
    }else if(StringUtils.isNullOrEmpty(oldpassword)){
        resultMap.put("result","error");
    }else{
        String userPassword = ((User) obj).getUserPassword();
        if(oldpassword.equals(userPassword)){
            resultMap.put("result","true");
        }else{
            resultMap.put("result","false");
        }
    }

    try {
        resp.setContentType("application/json");
        PrintWriter writer = resp.getWriter();
        writer.write(JSONArray.toJSONString(resultMap));
        writer.flush();
        writer.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

}


### 3.测试



## 六、用户管理实现



### 1.获取用户数量



#### 1.UserDao

//查询用户总数 public int getUserCount(Connection connection,String username,int userRole) throws SQLException;


#### 2.UserDaoImpl




public int getUserCount(Connection connection, String username, int userRole) throws SQLException {
    PreparedStatement pstm = null;
    ResultSet rs = null;
    int count = 0;
    if(connection != null){
        StringBuilder sql = new StringBuilder();
        sql.append("select count(1) as count from smbms\_user u,smbms\_role r where u.userRole = r.id");
        ArrayList<Object> list = new ArrayList<Object>();

        if(!StringUtils.isNullOrEmpty(username)){
            sql.append(" and u.userName like ? ");
            list.add("%"+username+"%");
        }

        if(userRole>0){
            sql.append(" and u.userRole = ? ");
            list.add(userRole);
        }

        Object[] params = list.toArray();
        rs = BaseDao.execute(connection,pstm,rs,sql.toString(),params);
        if(rs.next()){
            count = rs.getInt("count");
        }
        BaseDao.closeResource(null,pstm,rs);
    }
    return count;
}


#### 3.UserService

//查询记录数 public int getUserCount(String username,int userRole);


#### 4.UserServiceImpl

public int getUserCount(String username, int userRole) { Connection connection = null; int count = 0; try { connection = BaseDao.getConnection(); count = userDao.getUserCount(connection,username,userRole); } catch (SQLException e) { e.printStackTrace(); }finally { BaseDao.closeResource(connection,null,null); } return count; }


### 2.用户列表页导入



#### 1.UserDao

//通过用户输入的条件查询用户列表 public List getUserList(Connection connection, String userName, int userRole, int currentPageNo, int pageSize) throws Exception;


#### 2.UserDaoImpl

//通过用户输入的条件查询用户列表 public List getUserList(Connection connection, String userName, int userRole, int currentPageNo, int pageSize) throws Exception { List userList = new ArrayList(); PreparedStatement pstm=null; ResultSet rs=null; if(connection!=null){ StringBuffer sql = new StringBuffer(); sql.append("select u.*,r.roleName as userRoleName from smbms_user u,smbms_role r where u.userRole = r.id"); List list = new ArrayList(); if(!StringUtils.isNullOrEmpty(userName)){ sql.append(" and u.userName like ?"); list.add("%"+userName+"%"); } if(userRole > 0){ sql.append(" and u.userRole = ?"); list.add(userRole); } sql.append(" order by creationDate DESC limit ?,?"); currentPageNo = (currentPageNo-1)*pageSize; list.add(currentPageNo); list.add(pageSize);

        Object[] params = list.toArray();
        System.out.println("sql ----> " + sql.toString());
        rs = BaseDao.execute(connection,pstm,rs,sql.toString(),params);
        while(rs.next()){
            User _user = new User();
            _user.setId(rs.getInt("id"));
            _user.setUserCode(rs.getString("userCode"));
            _user.setUserName(rs.getString("userName"));
            _user.setGender(rs.getInt("gender"));
            _user.setBirthday(rs.getDate("birthday"));
            _user.setPhone(rs.getString("phone"));
            _user.setUserRole(rs.getInt("userRole"));
            _user.setUserRoleName(rs.getString("userRoleName"));
            userList.add(_user);
        }
        BaseDao.closeResource(null, pstm, rs);
    }
    return userList;
}


#### 3.UserService

//根据条件查询用户列表 public List getUserList(String queryUserName, int queryUserRole, int currentPageNo, int pageSize);


#### 4.UserServiceImpl

public List getUserList(String queryUserName, int queryUserRole, int currentPageNo, int pageSize) { Connection connection = null; List userList = null; try { connection = BaseDao.getConnection(); userList = userDao.getUserList(connection, queryUserName,queryUserRole,currentPageNo,pageSize); } catch (Exception e) { e.printStackTrace(); }finally{ BaseDao.closeResource(connection, null, null); } return userList; }


### 3.获取角色操作



#### 1.RoleDao

//获取角色列表 public List getRoleList(Connection connection) throws SQLException;


#### 2.RoleDaoImpl

package com.mario.dao.role;

import com.mario.dao.BaseDao; import com.mario.entity.Role;

import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List;

public class RoleDaoImpl implements RoleDao{ //获取角色列表 public List getRoleList(Connection connection) throws SQLException { PreparedStatement pstm = null; ResultSet rs = null; ArrayList rolesList = new ArrayList();

    if(connection != null){
        String sql = "select \* from smbms\_role";
        Object[] params = {};
        rs =  BaseDao.execute(connection,pstm,rs,sql,params);

        while (rs.next()){
            Role _role = new Role();
            _role.setId( rs.getInt("id"));
            _role.setRoleCode( rs.getString("roleCode"));
            _role.setRoleName( rs.getString("roleName"));
            rolesList.add(_role);
        }
        BaseDao.closeResource(null, pstm, rs);
    }
    return rolesList;
}

}


#### 3.RoleService

//获取角色列表 public List getRoleList();


#### 4.RoleServiceImpl

package com.mario.service.role;

import com.mario.dao.BaseDao; import com.mario.dao.role.RoleDao; import com.mario.dao.role.RoleDaoImpl; import com.mario.entity.Role;

import java.sql.Connection; import java.util.List;

public class RoleServiceImpl implements RoleService{

private RoleDao roleDao;
public RoleServiceImpl(){
    roleDao = new RoleDaoImpl();
}

//获取角色列表
public List<Role> getRoleList() {
    Connection connection=null;
    List<Role> roleList=null;
    try {
        connection= BaseDao.getConnection();
        roleList = roleDao.getRoleList(connection);
    } catch (Exception e) {
        e.printStackTrace();
    }finally {
        BaseDao.closeResource(connection,null,null);
    }
    return roleList;
}

}


### 4.用户显示的Servlet


* 获取用户前端的数据（查询）
* 判断请求是否需要执行，看参数的值判断
* 为了实现分页，需要计算出当前页面和总页面，页面的大小
* 用户列表展示
* 返回前端

package com.mario.servlet;

import com.alibaba.fastjson.JSONArray; import com.mario.entity.Role; import com.mario.entity.User; import com.mario.service.role.RoleService; import com.mario.service.role.RoleServiceImpl; import com.mario.service.user.UserService; import com.mario.service.user.UserServiceImpl; import com.mario.util.Constants; import com.mario.util.PageSupport; import com.mysql.jdbc.StringUtils;

import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.io.PrintWriter; import java.util.HashMap; import java.util.List; import java.util.Map;

public class UserServlet extends HttpServlet {

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    String method = req.getParameter("method");
    if(method.equals("savepwd") && method != null){
        this.updatePwd(req,resp);
    }else if(method.equals("pwdmodify") && method != null){
        this.pwdModify(req,resp);
    }else if(method.equals("query") && method != null){
        this.query(req,resp);
    }
}

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    doGet(req, resp);
}

public void query(HttpServletRequest req, HttpServletResponse resp){
    //接收前端传来的参数
    String queryUserName = req.getParameter("queryname");
    String temp = req.getParameter("queryUserRole");//从前端传回来的用户角色码不知是否为空或者是有效角色码，所以暂存起来
    String pageIndex = req.getParameter("pageIndex");
    int queryUserRole=0;

    //通过UserServiceImpl得到用户列表,用户数
    UserServiceImpl userService = new UserServiceImpl();
    List<User> userList = null;//用来存储用户列表

    //设置每页显示的页面容量
    int pageSize = 5;
    //设置当前的默认页码
    int currentPageNo=1;

    //前端传来的参数若不符合查询sql语句，即如果用户不进行设置，值为空会影响sql查询，需要给它们进行一些约束
    if(queryUserName==null){//这里为空，说明用户没有输入要查询的用户名，则sql语句传值为""，%%，会查询所有记录
        queryUserName="";
    }
    if(temp!=null && !temp.equals("")){
        //不为空，说明前端有传来的用户所设置的userCode，更新真正的角色码
        queryUserRole=Integer.parseInt(temp);//强制转换，前端传递的参数都是默认字符串，要转成int类型
    }
    if(pageIndex!=null){//说明当前用户有进行设置跳转页面
        currentPageNo=Integer.valueOf(pageIndex);
    }

    //有了用户名和用户角色后可以开始查询了，所以需要显示当前查询到的总记录条数
    int totalCount = userService.getUserCount(queryUserName, queryUserRole);
    //根据总记录条数以及当前每页的页面容量可以算出，一共有几页，以及最后一页的显示条数
    PageSupport pageSupport = new PageSupport();
    pageSupport.setCurrentPageNo(currentPageNo);
    pageSupport.setPageSize(pageSize);
    pageSupport.setTotalCount(totalCount);

    //可显示的总页数
    int totalPageCount=pageSupport.getTotalPageCount();

    //约束首位页，即防止用户输入的页面索引小于1或者大于总页数
    if(currentPageNo<1){
        currentPageNo=1;
    }else if(currentPageNo>totalPageCount){
        currentPageNo=totalPageCount;
    }

    //有了，待查询条件，当前页码，以及每页的页面容量后，就可以给出每页的具体显示情况了
     userList = userService.getUserList(queryUserName, queryUserRole, currentPageNo, pageSize);
    req.setAttribute("userList",userList);

    //通过RoleServiceImpl得到角色表
    RoleService roleService = new RoleServiceImpl();
    List<Role> roleList = roleService.getRoleList();//用来存储角色表
    //得到了用户表与角色表以及各种经过处理后的参数，都存进req中
    req.setAttribute("roleList",roleList);
    req.setAttribute("totalCount", totalCount);
    req.setAttribute("currentPageNo", currentPageNo);
    req.setAttribute("totalPageCount", totalPageCount);
    req.setAttribute("queryUserName", queryUserName);
    req.setAttribute("queryUserRole", queryUserRole);
    
    //将所得到的的所有req参数送回给前端
    try {
        req.getRequestDispatcher("userlist.jsp").forward(req,resp);
    } catch (ServletException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

//修改密码
public void updatePwd(HttpServletRequest req, HttpServletResponse resp){
    Object obj = req.getSession().getAttribute(Constants.USER_SESSION);
    String newpassword = req.getParameter("newpassword");

    System.out.println(newpassword);

    boolean flag = false;

    if(obj != null && newpassword != null){
        UserService userService = new UserServiceImpl();
        flag = userService.updatePwd(((User) obj).getId(), newpassword);
        if(flag){
            req.setAttribute("message","修改密码成功");
            req.getSession().removeAttribute(Constants.USER_SESSION);
        }else{
            req.setAttribute("message","密码修改失败");
        }
    }else{
        req.setAttribute("message","新密码有问题");
    }
    try {
        req.getRequestDispatcher("pwdmodify.jsp").forward(req,resp);
    } catch (ServletException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

//验证旧密码,session中有用户的密码
public void pwdModify(HttpServletRequest req, HttpServletResponse resp){
    Object obj = req.getSession().getAttribute(Constants.USER_SESSION);
    String oldpassword = req.getParameter("oldpassword");

    Map<String, String> resultMap = new HashMap<String, String>();

    if(obj==null){
        resultMap.put("result","sessionerror");
    }else if(StringUtils.isNullOrEmpty(oldpassword)){
        resultMap.put("result","error");

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