SMBMS

SMBMS是超市订单管理系统的简称

数据库：

项目如何让搭建？

考虑使用不使用Maven？ 依赖，jar

项目搭建准备工作

1.搭建一个mavenweb项目

2.配置Tomcat

3.测试项目是否能够跑起来

4.导入项目中会遇到的jar包

jsp,servlet,mysql驱动，jstl，stand...

  <dependencies><dependency><groupId>javax.servlet</groupId><artifactId>servlet-api</artifactId><version>2.5</version></dependency><dependency><groupId>javax.servlet.jsp</groupId><artifactId>jsp-api</artifactId><version>2.2</version></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.47</version></dependency><!--JSTL表达式的依赖--><dependency><groupId>javax.servlet.jsp.jstl</groupId><artifactId>jstl-api</artifactId><version>1.2</version></dependency><!--standard标签库--><dependency><groupId>taglibs</groupId><artifactId>standard</artifactId><version>1.1.2</version></dependency></dependencies>

5.创建项目包结构

6.编写实体类

package com.jibu.pojo;import java.util.Date;public class User {private Integer id; //idprivate String userCode; //用户编码private String userName; //用户名称private String userPassword; //用户密码private Integer gender;  //性别private Date birthday;  //出生日期private String phone;   //电话private String address; //地址private Integer userRole;    //用户角色private Integer createdBy;   //创建者private Date creationDate; //创建时间private Integer modifyBy;     //更新者private Date modifyDate;   //更新时间private Integer age;//年龄private String userRoleName;    //用户角色名称public String getUserRoleName() {return userRoleName;}public void setUserRoleName(String userRoleName) {this.userRoleName = userRoleName;}public Integer getAge() {/*long time = System.currentTimeMillis()-birthday.getTime();Integer age = Long.valueOf(time/365/24/60/60/1000).IntegerValue();*/Date date = new Date();Integer age = date.getYear()-birthday.getYear();return age;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getUserCode() {return userCode;}public void setUserCode(String userCode) {this.userCode = userCode;}public String getUserName() {return userName;}public void setUserName(String userName) {this.userName = userName;}public String getUserPassword() {return userPassword;}public void setUserPassword(String userPassword) {this.userPassword = userPassword;}public Integer getGender() {return gender;}public void setGender(Integer gender) {this.gender = gender;}public Date getBirthday() {return birthday;}public void setBirthday(Date birthday) {this.birthday = birthday;}public String getPhone() {return phone;}public void setPhone(String phone) {this.phone = phone;}public String getAddress() {return address;}public void setAddress(String address) {this.address = address;}public Integer getUserRole() {return userRole;}public void setUserRole(Integer userRole) {this.userRole = userRole;}public Integer getCreatedBy() {return createdBy;}public void setCreatedBy(Integer createdBy) {this.createdBy = createdBy;}public Date getCreationDate() {return creationDate;}public void setCreationDate(Date creationDate) {this.creationDate = creationDate;}public Integer getModifyBy() {return modifyBy;}public void setModifyBy(Integer modifyBy) {this.modifyBy = modifyBy;}public Date getModifyDate() {return modifyDate;}public void setModifyDate(Date modifyDate) {this.modifyDate = modifyDate;}}

package com.jibu.pojo;import java.util.Date;public class Role {private Integer id;   //idprivate String roleCode; //角色编码private String roleName; //角色名称private Integer createdBy; //创建者private Date creationDate; //创建时间private Integer modifyBy; //更新者private Date modifyDate;//更新时间public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getRoleCode() {return roleCode;}public void setRoleCode(String roleCode) {this.roleCode = roleCode;}public String getRoleName() {return roleName;}public void setRoleName(String roleName) {this.roleName = roleName;}public Integer getCreatedBy() {return createdBy;}public void setCreatedBy(Integer createdBy) {this.createdBy = createdBy;}public Date getCreationDate() {return creationDate;}public void setCreationDate(Date creationDate) {this.creationDate = creationDate;}public Integer getModifyBy() {return modifyBy;}public void setModifyBy(Integer modifyBy) {this.modifyBy = modifyBy;}public Date getModifyDate() {return modifyDate;}public void setModifyDate(Date modifyDate) {this.modifyDate = modifyDate;}}

package com.jibu.pojo;import java.util.Date;public class Provider {private Integer id;   //idprivate String proCode; //供应商编码private String proName; //供应商名称private String proDesc; //供应商描述private String proContact; //供应商联系人private String proPhone; //供应商电话private String proAddress; //供应商地址private String proFax; //供应商传真private Integer createdBy; //创建者private Date creationDate; //创建时间private Integer modifyBy; //更新者private Date modifyDate;//更新时间public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getProCode() {return proCode;}public void setProCode(String proCode) {this.proCode = proCode;}public String getProName() {return proName;}public void setProName(String proName) {this.proName = proName;}public String getProDesc() {return proDesc;}public void setProDesc(String proDesc) {this.proDesc = proDesc;}public String getProContact() {return proContact;}public void setProContact(String proContact) {this.proContact = proContact;}public String getProPhone() {return proPhone;}public void setProPhone(String proPhone) {this.proPhone = proPhone;}public String getProAddress() {return proAddress;}public void setProAddress(String proAddress) {this.proAddress = proAddress;}public String getProFax() {return proFax;}public void setProFax(String proFax) {this.proFax = proFax;}public Integer getCreatedBy() {return createdBy;}public void setCreatedBy(Integer createdBy) {this.createdBy = createdBy;}public Date getCreationDate() {return creationDate;}public void setCreationDate(Date creationDate) {this.creationDate = creationDate;}public Integer getModifyBy() {return modifyBy;}public void setModifyBy(Integer modifyBy) {this.modifyBy = modifyBy;}public Date getModifyDate() {return modifyDate;}public void setModifyDate(Date modifyDate) {this.modifyDate = modifyDate;}}

package com.jibu.pojo;import java.math.BigDecimal;
import java.util.Date;public class Bill {private Integer id;   //idprivate String billCode; //账单编码private String productName; //商品名称private String productDesc; //商品描述private String productUnit; //商品单位private BigDecimal productCount; //商品数量private BigDecimal totalPrice; //总金额private Integer isPayment; //是否支付private Integer providerId; //供应商IDprivate Integer createdBy; //创建者private Date creationDate; //创建时间private Integer modifyBy; //更新者private Date modifyDate;//更新时间private String providerName;//供应商名称public String getProviderName() {return providerName;}public void setProviderName(String providerName) {this.providerName = providerName;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getBillCode() {return billCode;}public void setBillCode(String billCode) {this.billCode = billCode;}public String getProductName() {return productName;}public void setProductName(String productName) {this.productName = productName;}public String getProductDesc() {return productDesc;}public void setProductDesc(String productDesc) {this.productDesc = productDesc;}public String getProductUnit() {return productUnit;}public void setProductUnit(String productUnit) {this.productUnit = productUnit;}public BigDecimal getProductCount() {return productCount;}public void setProductCount(BigDecimal productCount) {this.productCount = productCount;}public BigDecimal getTotalPrice() {return totalPrice;}public void setTotalPrice(BigDecimal totalPrice) {this.totalPrice = totalPrice;}public Integer getIsPayment() {return isPayment;}public void setIsPayment(Integer isPayment) {this.isPayment = isPayment;}public Integer getProviderId() {return providerId;}public void setProviderId(Integer providerId) {this.providerId = providerId;}public Integer getCreatedBy() {return createdBy;}public void setCreatedBy(Integer createdBy) {this.createdBy = createdBy;}public Date getCreationDate() {return creationDate;}public void setCreationDate(Date creationDate) {this.creationDate = creationDate;}public Integer getModifyBy() {return modifyBy;}public void setModifyBy(Integer modifyBy) {this.modifyBy = modifyBy;}public Date getModifyDate() {return modifyDate;}public void setModifyDate(Date modifyDate) {this.modifyDate = modifyDate;}}

 ORM映射：表和类映射

7.编写基础公共类

        1.数据库配置文件
        db.properties

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/jdbc?useUnicode=true&characterEncoding=utf-8&useSSL=false
username=root
password=123456

        2.编写数据库的公共类

package com.jibu.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();}return connection;}//编写查询公共方法public static ResultSet execute(Connection connection,String sql,Object[] params,ResultSet resultSet,PreparedStatement preparedStatement) 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,占位符从1开始，但是我们的数组是从0开始！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,String sql,Object[] params,PreparedStatement preparedStatement) throws SQLException {preparedStatement = connection.prepareStatement(sql);for (int i = 1; i < params.length; i++) {//setObject,占位符从1开始，但是我们的数组是从0开始！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 (resultSet != null) {try {resultSet.close();//GC回收resultSet = null;} catch (SQLException e) {e.printStackTrace();flag = false;}}if (preparedStatement != null) {try {preparedStatement.close();//GC回收preparedStatement = null;} catch (SQLException e) {e.printStackTrace();flag = false;}}if (connection != null) {try {connection.close();//GC回收connection = null;} catch (SQLException e) {e.printStackTrace();flag = false;}}return flag;}
}

         3.编写字符编码过滤器

package com.jibu.filter;import javax.servlet.*;
import java.io.IOException;public class CharacterEncodingFilter implements Filter {@Overridepublic void init(FilterConfig filterConfig) throws ServletException {}@Overridepublic void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {request.setCharacterEncoding("utf-8");response.setCharacterEncoding("utf-8");chain.doFilter(request,response);}@Overridepublic void destroy() {}
}

    <!--字符编码过滤器--><filter><filter-name>CharacterEncodingFilter</filter-name><filter-class>com.jibu.filter.CharacterEncodingFilter</filter-class></filter><filter-mapping><filter-name>CharacterEncodingFilter</filter-name><url-pattern>/*</url-pattern></filter-mapping>

8.导入静态资源 

地址：smbms: 狂神说Java Javaweb练习项目 超市订单管理系统 SMBMS smbmsTomcat10.1.5+jdk21+Mariadb

登录功能实现

流程结构

1.编写前端页面 

2.设置首页

    <!--设置欢迎页面--><welcome-file-list><welcome-file>login.jsp</welcome-file></welcome-file-list>

3.编写Dao层登录用户登录的接口

package com.jibu.dao.user;import com.jibu.pojo.User;import java.sql.Connection;
import java.sql.SQLException;public interface UserDao {//得到要登陆的用户public User getLoginUser(Connection connection,String userCode) throws SQLException;}

4. 编写接口的实现类

package com.jibu.dao.user;import com.jibu.dao.BaseDao;
import com.jibu.pojo.User;import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;public class UserDaoImpl implements UserDao{@Overridepublic User getLoginUser(Connection connection, String userCode) throws SQLException {PreparedStatement pstm = null;ResultSet rs = null;User user = null;if (connection != null) {String sql = "select * from smbms_user where userCode=?";Object[] params = {userCode};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;}
}

5.业务层接口

package com.jibu.service.user;import com.jibu.pojo.User;public interface UserService {//用户登录public User login(String userCode,String password);
}

6.业务层实现类 

package com.jibu.service.user;import com.jibu.dao.BaseDao;
import com.jibu.dao.user.UserDao;
import com.jibu.dao.user.UserDaoImpl;
import com.jibu.pojo.User;
import org.junit.Test;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();}@Overridepublic User login(String userCode, String password) {Connection connection = null;User user = null;try {connection = BaseDao.getConnection();//通过业务层调用具体的数据库操作user = userDao.getLoginUser(connection, userCode);} catch (SQLException e) {e.printStackTrace();}finally {BaseDao.closeResource(connection,null,null);}return user;}
//    @Test
//    public void test(){
//        UserServiceImpl userService = new UserServiceImpl();
//        User admin = userService.login("admin", "1234567");
//        System.out.println(admin.getUserPassword());
//    }
}

7.编写servlet

package com.jibu.servlet.user;import com.jibu.pojo.User;
import com.jibu.service.user.UserService;
import com.jibu.service.user.UserServiceImpl;
import com.jibu.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，调用业务层代码@Overrideprotected 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；UserService userService = new UserServiceImpl();User user = userService.login(userCode, userPassword); //这里已经把登录的人给查出来了if (user!=null){//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);//跳转到主页resp.sendRedirect("jsp/frame.jsp");}else {//查无此人，无法登录//转发会登录页面，顺带提示它，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);}}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {doGet(req, resp);}
}

 8.注册Servlet

    <!--Servlet--><servlet><servlet-name>LoginServlet</servlet-name><servlet-class>com.jibu.servlet.user.LoginServlet</servlet-class></servlet><servlet-mapping><servlet-name>LoginServlet</servlet-name><url-pattern>/login.do</url-pattern></servlet-mapping>

9.测试访问，确保以上功能成功！

登录功能优化 

注销功能：

思路：一处Session，返回登录页面

package com.jibu.servlet.user;import com.jibu.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 {@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {//移除用户的Session：Constants.USER_SESSIONreq.getSession().removeAttribute(Constants.USER_SESSION);resp.sendRedirect("/login.jsp");//返回登录页面}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {doGet(req, resp);}
}

注销XML

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

登录拦截器

编写一个过滤器，并注册

package com.jibu.filter;import com.jibu.pojo.User;
import com.jibu.util.Constants;import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;public class SysFilter implements Filter {@Overridepublic void init(FilterConfig filterConfig) throws ServletException {}@Overridepublic void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IOException, ServletException {HttpServletRequest request = (HttpServletRequest) req;HttpServletResponse response = (HttpServletResponse) resp;//过滤器，从Session中获取用户，User user = (User) request.getSession().getAttribute(Constants.USER_SESSION);if (user!=null){// 用户已登录，允许请求继续chain.doFilter(req,resp);}  else {// 用户未登录，重定向到登录页面或显示错误信息response.sendRedirect("/smbms/error.jsp");}}@Overridepublic void destroy() {}
}

    <!--用户登录过滤器--><filter><filter-name>SysFilter</filter-name><filter-class>com.jibu.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，权限都要保证OK！

密码修改

1.导入前端素材

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

2.写项目，建议从底层向上写 

3.UserDao接口

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

4.UserDao接口实现类

    //修改当前用户密码@Overridepublic 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

    @Overridepublic 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 flag;}

 7.记得实现复用，需要提取出方法

package com.jibu.servlet.user;import com.jibu.pojo.User;
import com.jibu.service.user.UserService;
import com.jibu.service.user.UserServiceImpl;
import com.jibu.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;//实现Servlet复用
public class UserServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {String method = req.getParameter("method");if (method.equals("savepwd")&&method!=null){this.updatePwd(req,resp);}}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {doGet(req,resp);}public void updatePwd(HttpServletRequest req, HttpServletResponse resp){//从Session里面拿ID;Object o = req.getSession().getAttribute(Constants.USER_SESSION);String newpassword = req.getParameter("newpassword");boolean flag = false;if (o!=null && newpassword!=null){UserService userService = new UserServiceImpl();flag = userService.updatePwd(((User) o).getId(), newpassword);if (flag){req.setAttribute("message","修改密码成功，请退出，使用新密码登录");//密码修改成功，移除当前Sessionreq.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();}}
}

    <servlet><servlet-name>UserServlet</servlet-name><servlet-class>com.jibu.servlet.user.UserServlet</servlet-class></servlet><servlet-mapping><servlet-name>UserServlet</servlet-name><url-pattern>/jsp/user.do</url-pattern></servlet-mapping>

 8.测试

优化密码修改使用Ajax

1.阿里巴巴的fastjson

    <dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>1.2.61</version></dependency>

2.后台代码修改

//修改密码public void updatePwd(HttpServletRequest req, HttpServletResponse resp){//从Session里面拿ID;Object o = req.getSession().getAttribute(Constants.USER_SESSION);String newpassword = req.getParameter("newpassword");boolean flag = false;if (o!=null && !StringUtils.isNullOrEmpty(newpassword)){UserService userService = new UserServiceImpl();flag = userService.updatePwd(((User) o).getId(), newpassword);if (flag){req.setAttribute("message","修改密码成功，请退出，使用新密码登录");//密码修改成功，移除当前Sessionreq.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){//从Session里面拿ID;Object o = req.getSession().getAttribute(Constants.USER_SESSION);String oldpassword = req.getParameter("oldpassword");//万能的Map : 结果集Map<String, String> resultMap = new HashMap<>();if (o==null){//session失效了，session过期了resultMap.put("result","sessionerror");}else if (StringUtils.isNullOrEmpty(oldpassword)){//输入的密码为空resultMap.put("result","error");}else {String userPassword = ((User) o).getUserPassword();//session中用户的密码if (oldpassword.equals(userPassword)){resultMap.put("result","true");}else {resultMap.put("result","false");}}try {resp.setContentType("application/json");PrintWriter writer = resp.getWriter();//JSONArray 阿里巴巴的JSON工具类，转换格式/*resultMap = ["result","sessionerror","result","error"]Json格式 = {key:value}*/writer.write(JSONArray.toJSONString(resultMap));writer.flush();writer.close();} catch (IOException e) {e.printStackTrace();}}

3.测试 

用户管理实现

思路：

1.导入分页的工具类

2.用户列表页面导入 

userlist.jsp

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

//根据用户名或者角色查询用户总数【最难理解的sql】@Overridepublic int getUserCount(Connection connection, String username, int userRole) throws SQLException {PreparedStatement pstm = null;ResultSet rs = null;int count = 0;if (connection!=null){StringBuffer sql = new StringBuffer();sql.append("select count(1) as count from smbms_user u ,smbms_role r where u.userRole = r.id");ArrayList<Object> list = new ArrayList<>();//存放我们的参数if (!StringUtils.isNullOrEmpty(username)){sql.append(" and u.userName like ?");list.add("%"+username+"%");//index：0}if (userRole>0){sql.append(" and u.userRole = ?");list.add(userRole);//index：1}//怎么把list转换为数组Object[] params = list.toArray();System.out.println("UserDaoImpl->getUserCount:"+sql.toString());//输出最后完整的SQL语句rs = BaseDao.execute(connection, pstm, rs, sql.toString(), params);if (rs.next()){count = rs.getInt("count");//从结果集中获取最终的数量}BaseDao.closeResource(null,pstm,rs);}return count;}

3.UserService

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

3.UserServiceImpl

    //查询记录数@Overridepublic 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、获取用户列表

1.UserDao

//通过条件查询-userList
public List<User> getUserList(Connection connection, String userName, int userRole, int currentPageNo, int pageSize)throws Exception;

2.UserDaoImpl

    @Overridepublic List<User> getUserList(Connection connection, String userName, int userRole, int currentPageNo, int pageSize) throws Exception {// TODO Auto-generated method stubPreparedStatement pstm = null;ResultSet rs = null;List<User> userList = new ArrayList<User>();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<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);}//在数据库中分页使用 limit startIndex，pageSize; 总数//0,5       1//5,5//10,5sql.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<User> getUserList(String queryUserName, int queryUserRole, int currentPageNo, int pageSize);

4.UserSeviceImpl

    @Overridepublic List<User> getUserList(String queryUserName, int queryUserRole, int currentPageNo, int pageSize) {// TODO Auto-generated method stubConnection connection = null;List<User> userList = null;System.out.println("queryUserName ---- > " + queryUserName);System.out.println("queryUserRole ---- > " + queryUserRole);System.out.println("currentPageNo ---- > " + currentPageNo);System.out.println("pageSize ---- > " + pageSize);try {connection = BaseDao.getConnection();userList = userDao.getUserList(connection, queryUserName,queryUserRole,currentPageNo,pageSize);} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}finally{BaseDao.closeResource(connection, null, null);}return userList;}

3、获取角色操作

为了我们职责统一，可以把角色的操作单独放在一个包中，和POJO类对应

1.RoleDao 

package com.jibu.dao.role;import com.jibu.pojo.Role;import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;public interface RoleDao {//获取角色列表public List<Role> getRoleList(Connection connection) throws SQLException;
}

2.RoleDaoImpl 

package com.jibu.dao.role;import com.jibu.dao.BaseDao;
import com.jibu.pojo.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@Overridepublic List<Role> getRoleList(Connection connection) throws SQLException {PreparedStatement pstm = null;ResultSet resultSet = null;ArrayList<Role> roleList = new ArrayList<>();if (connection != null){String sql = "select * from smbms_role";Object[] params = {};resultSet = BaseDao.execute(connection, pstm, resultSet, sql, params);while (resultSet.next()){Role _role = new Role();_role.setId(resultSet.getInt("id"));_role.setRoleCode(resultSet.getString("userCode"));_role.setRoleName(resultSet.getString("userName"));roleList.add(_role);}BaseDao.closeResource(null,pstm,resultSet);}return roleList;}
}

3.RoleService 

package com.jibu.service.role;import com.jibu.pojo.Role;import java.util.List;public interface RoleService {//获取角色列表public List<Role> getRoleList();
}

 4.RoleServiceImpl

package com.jibu.service.role;import com.jibu.dao.BaseDao;
import com.jibu.dao.role.RoleDao;
import com.jibu.dao.role.RoleDaoImpl;
import com.jibu.pojo.Role;import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;public class RoleServiceImpl implements RoleService{//引入Daoprivate RoleDao roleDao;public RoleServiceImpl() {roleDao = new RoleDaoImpl();}@Overridepublic List<Role> getRoleList() {Connection connection = null;List<Role> roleList = null;try {connection = BaseDao.getConnection();roleList = roleDao.getRoleList(connection);} catch (SQLException e) {e.printStackTrace();}finally {BaseDao.closeResource(connection,null,null);}return roleList;}
}

4、用户显示的Servlet

1.获取用户前端的数据（查询）

2.判断请求是否需要执行，看参数的值判断

3.为了实现分页，需要计算出当前页面和总页面，页面大小

4.用户列表展示

5.返回前端

    //重点、难点public void query(HttpServletRequest req, HttpServletResponse resp){//查询用户列表//从前端获取数据String queryUserName = req.getParameter("queryname");String temp = req.getParameter("queryUserRole");String pageIndex = req.getParameter("pageIndex");int queryUserRole = 0;//获取用户列表UserServiceImpl userService = new UserServiceImpl();List<User> userList = null;//第一次走这个请求一定是第一页，并且页面大小是固定的int pageSize = 5;//可以把这个写到配置文件里，方便后期修改；int currentPageNo = 1;if (queryUserName == null){queryUserName = "";}if (temp!=null && !temp.equals("")){queryUserRole = Integer.parseInt(temp); //给查询赋值}if (pageIndex!=null){currentPageNo = Integer.parseInt(pageIndex);}//获取用户的总数(分页：   上一页，下一页的情况)int totalCount = userService.getUserCount(queryUserName, queryUserRole);//总页数支持PageSupport pageSupport = new PageSupport();pageSupport.setCurrentPageNo(currentPageNo);pageSupport.setPageSize(pageSize);pageSupport.setTotalCount(totalCount);int totalPageCount = pageSupport.getTotalPageCount();//最大页数//控制首页和尾页//如果页面要小于1了，就显示第一页的东西if (totalPageCount<1){totalPageCount = 1;} else if (currentPageNo>totalPageCount) {//当前页面大于了最后一页；currentPageNo = totalPageCount;}//获取用户列表展示userList = userService.getUserList(queryUserName, queryUserRole, currentPageNo, pageSize);req.setAttribute("userList",userList);RoleServiceImpl roleService = new RoleServiceImpl();List<Role> roleList = roleService.getRoleList();req.setAttribute("roleList",roleList);req.setAttribute("totalCount",totalCount);req.setAttribute("currentPageNo",currentPageNo);req.setAttribute("totalPageCount",totalPageCount);req.setAttribute("queryUserName",queryUserName);req.setAttribute("queryUserRole",queryUserRole);//返回前端try {req.getRequestDispatcher("userlist.jsp").forward(req,resp);} catch (ServletException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}

小黄鸭调试法