JavaWeb 期末复习

//查询所有的员工信息

List<Emp> getAllErp();

//查询详细员工信息

Emp getEmpById(int id);

//新增员工

boolean insertEmp(Emp emp);

//删除员工

boolean delEmp(int id);

//修改员工信息

boolean updateEmp(Emp emp);

}

UserDaoImpl.java

package com.blb.dao.impl;

import com.blb.dao.UserDao;

import com.blb.entity.User;

import com.blb.util.DBUtil;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

/**

• UserDao 的实现类，做数据库表的增删改查

*/

public class UserDaoImpl implements UserDao {

Connection conn = null;

PreparedStatement ps = null;

ResultSet rs =null;

/**

• 通过用户名从数据库查询用户信息，并返回

• idea 提示快捷键 alt+enter

• @param user

• @return

*/

@Override

public User getUserByUserName(User user) {

//写数据查询

//获取连接

conn = DBUtil.getConnection();

User user1 = null;

//Sql 语句

String sql = "select * from user where u_name = ?";

try {

//预编译

ps=conn.prepareStatement(sql);

//值的插入

ps.setString(1,user.getUsername());

//查询

rs = ps.executeQuery();

while (rs.next()){

int id = rs.getInt("id");

String username = rs.getString("u_name");

String password = rs.getString("u_pwd");

//实例化 User 对象

user1 = new User(id,username,password);

//System.out.println(user1);

}

} catch (SQLException e) {

e.printStackTrace();

}

return user1;

}

@Override

public boolean insertUser(User user) {

conn = DBUtil.getConnection();

String sql = "insert into user (u_name,u_pwd) values(?,?)";

//

try {

ps = conn.prepareStatement(sql);

ps.setString(1,user.getUsername());

ps.setString(2,user.getPassword());

int count = ps.executeUpdate();

return count>0;

} catch (SQLException e) {

e.printStackTrace();

}

return false;

}

}

EmpDaoImpl.java

package com.blb.dao.impl;

import com.blb.dao.EmpDao;

import com.blb.entity.Emp;

import com.blb.util.DBUtil;

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 EmpDaoImpl implements EmpDao {

Connection conn = null;

PreparedStatement ps = null;

ResultSet rs = null;

/**

• 查询所有员工信息

• @return 存储员工对象的集合

*/

@Override

public List<Emp> getAllErp() {

List<Emp> emps = new ArrayList<>();

conn = DBUtil.getConnection();

String sql = "select * from erp";

try {

ps = conn.prepareStatement(sql);

rs = ps.executeQuery();

while (rs.next()) {

int id = rs.getInt("s_id");

String erpName = rs.getString("s_name");

String deptName = rs.getString("dept_name");

Emp emp = new Emp(id, erpName, deptName);

emps.add(emp);

}

} catch (SQLException e) {

e.printStackTrace();

}

return emps;

}

/**

• 通过 id 查询对应员工的详细信息

• @param id

• @return emp 对象

*/

@Override

public Emp getEmpById(int id) {

conn = DBUtil.getConnection();

String sql = "Select * from erp where s_id = ?";

try {

ps = conn.prepareStatement(sql);

ps.setInt(1, id);

rs = ps.executeQuery();

while (rs.next()){

int sid = rs.getInt("s_id");

String erpName = rs.getString("s_name");

String deptName = rs.getString("dept_name");

Emp emp = new Emp(sid,erpName,deptName);

return emp;

}

} catch (SQLException e) {

e.printStackTrace();

}

return null;

}

/**

• 新增员工

• @param emp

• @return 布尔信息

*/

@Override

public boolean insertEmp(Emp emp) {

conn = DBUtil.getConnection();

String sql = "insert into erp (s_name,dept_name) values(?,?)";

try {

ps = conn.prepareStatement(sql);

ps.setString(1,emp.getErpName());

ps.setString(2,emp.getDeptName());

int count = ps.executeUpdate();

return count>0;

} catch (SQLException e) {

e.printStackTrace();

}

return false;

}

/**

• 删除员工

• @param id

• @return 布尔值

*/

@Override

public boolean delEmp(int id) {

conn = DBUtil.getConnection();

String sql = "delete from erp where s_id = ?";

try {

ps = conn.prepareStatement(sql);

ps.setInt(1,id);

int count = ps.executeUpdate();

return count>0;

} catch (SQLException e) {

e.printStackTrace();

}

return false;

}

@Override

public boolean updateEmp(Emp emp) {

conn = DBUtil.getConnection();

String sql = "update erp set s_name =? , dept_name = ? where s_id = ?";

try {

ps = conn.prepareStatement(sql);

ps.setString(1,emp.getErpName());

ps.setString(2,emp.getDeptName());

ps.setInt(3,emp.getId());

int count = ps.executeUpdate();

return count>0;

} catch (SQLException e) {

e.printStackTrace();

}

return false;

}

}

service 层

UserService（接口）

package com.blb.service;

import com.blb.entity.User;

/**

• service 接口，一个 login（登录判断）

*/

public interface UserService {

//user 其实是 servlet 获取到的用户信息，封装的 user 对象

boolean login(User user);

//注册方法

boolean register(User user);

}

EmpService（接口）

package com.blb.service;

import com.blb.entity.Emp;

import java.util.List;

public interface EmpService {

List<Emp> getAllErp();

Emp getEmpById(int id);

boolean insertEmp(Emp emp);

boolean delEmp(int id);

boolean updateEmp(Emp emp);

}

UserServiceImpl.java

package com.blb.service.impl;

import com.blb.dao.UserDao;

import com.blb.dao.impl.UserDaoImpl;

import com.blb.entity.User;

import com.blb.service.UserService;

public class UserServiceImpl implements UserService {

UserDao userDao = new UserDaoImpl();

/**

• 登录的实现方法

• @param user

• @return

*/

@Override

public boolean login(User user) {

User user1 = userDao.getUserByUserName(user);

if (user1==null){

return false;

}else if (!user.getPassword().equals(user1.getPassword())){

return false;

}

return true;

}

/**

• 注册的实现方法

• @param user

• @return

*/

@Override

public boolean register(User user) {

System.out.println(userDao.getUserByUserName(user));

if (userDao.getUserByUserName(user)!=null){

return false;

} if (userDao.insertUser(user)==false){

return false;

}

return true;

}

}

EmpServiceImpl.java

package com.blb.service.impl;

import com.blb.dao.EmpDao;

import com.blb.dao.impl.EmpDaoImpl;

import com.blb.entity.Emp;

import com.blb.service.EmpService;

import java.util.List;

public class EmpServiceImpl implements EmpService {

EmpDao empDao = new EmpDaoImpl();

@Override

public List<Emp> getAllErp() {

return empDao.getAllErp();

}

@Override

public Emp getEmpById(int id) {

return empDao.getEmpById(id);

}

@Override

public boolean insertEmp(Emp emp) {

return empDao.insertEmp(emp);

}

@Override

public boolean delEmp(int id) {

return empDao.delEmp(id);

}

@Override

public boolean updateEmp(Emp emp) {

return empDao.updateEmp(emp);

}

}

Servlet 层：对接我们的 JSP 页面

DoAddServlet.java

package com.blb.servlet;

import com.blb.entity.Emp;

import com.blb.service.EmpService;

import com.blb.service.impl.EmpServiceImpl;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.IOException;

@WebServlet("/doAdd")

public class DoAddServlet extends HttpServlet {

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

//获取 jsp 页面的员工信息

String empName = req.getParameter("empName");

String deptName = req.getParameter("deptName");

//封装员工对象

Emp emp = new Emp(empName,deptName);

//实例化 empService

EmpService empService = new EmpServiceImpl();

//获取新增结果

boolean res = empService.insertEmp(emp);

//如果成功，则返回首页，失败则提示信息

if (res){

req.getRequestDispatcher("/toIndex").forward(req,resp);

}else{

req.setAttribute("msg","新增失败");

req.getRequestDispatcher("/add.jsp").forward(req,resp);

}

}

}

DoDeleteServlet.java

package com.blb.servlet;

import com.blb.service.EmpService;

import com.blb.service.impl.EmpServiceImpl;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.IOException;

@WebServlet("/doDelete")

public class DoDeleteServlet extends HttpServlet {

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

int id = Integer.parseInt(req.getParameter("id"));

EmpService empService = new EmpServiceImpl();

boolean res = empService.delEmp(id);

if(res){

req.getRequestDispatcher("/toIndex").forward(req,resp);

}else {

req.setAttribute("msg","删除失败");

req.getRequestDispatcher("/toIndex").forward(req,resp);

}

}

}

DoRegisterServlet.java

package com.blb.servlet;

import com.blb.entity.User;

import com.blb.service.UserService;

import com.blb.service.impl.UserServiceImpl;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.IOException;

@WebServlet("/doRegister")

public class DoRegisterServlet extends HttpServlet {

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

UserService userService = new UserServiceImpl();

//获取 jsp 页面数据

String username = req.getParameter("username");

String password = req.getParameter("password");

//实例化 User 对象

User user = new User(username,password);

boolean res = userService.register(user);

System.out.println(res);

if (res){

req.getRequestDispatcher("/login.jsp").forward(req,resp);

}else {

req.getRequestDispatcher("/register.jsp").forward(req,resp);

}

}

}

DoSelectServlet.java

package com.blb.servlet;

import com.blb.entity.Emp;

import com.blb.service.EmpService;

import com.blb.service.impl.EmpServiceImpl;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

import java.io.IOException;

@WebServlet("/doSelect")

public class DoSelectServlet extends HttpServlet {

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

HttpSession session = req.getSession();

int id = Integer.parseInt(req.getParameter("id"));

EmpService empService = new EmpServiceImpl();

Emp emp = empService.getEmpById(id);

session.setAttribute("emp",emp);

req.getRequestDispatcher("/xq.jsp").forward(req,resp);

}

}

DoUpdateServlet.java

package com.blb.servlet;

import com.blb.entity.Emp;

import com.blb.service.EmpService;

import com.blb.service.impl.EmpServiceImpl;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.IOException;

@WebServlet("/doUpdate")

public class DoUpdateServlet extends HttpServlet {

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

//获取 jsp 页面的员工信息

String empName = req.getParameter("empName");

String deptName = req.getParameter("deptName");

int id = Integer.parseInt(req.getParameter("id"));

//封装员工对象

Emp emp = new Emp(id,empName,deptName);

//实例化 empService

EmpService empService = new EmpServiceImpl();

boolean res = empService.updateEmp(emp);

if(res){

req.getRequestDispatcher("/toIndex").forward(req,resp);

}else {

req.setAttribute("msg","更新失败");

req.getRequestDispatcher("/toIndex").forward(req,resp);

}

}

}

IndexServlet.java

package com.blb.servlet;

import com.blb.entity.Emp;

import com.blb.service.EmpService;

import com.blb.service.impl.EmpServiceImpl;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

import java.io.IOException;

import java.util.List;

@WebServlet("/toIndex")

public class IndexServlet extends HttpServlet {

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

//

HttpSession session = req.getSession();

EmpService empService = new EmpServiceImpl();

List<Emp> emps = empService.getAllErp();

session.setAttribute("emps", emps);

resp.sendRedirect("/User_demo_war_exploded/index.jsp");

}

@Override

protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

doGet(req,resp);

}

}

LoginServlet.java

package com.blb.servlet;

import com.blb.entity.User;

import com.blb.service.UserService;

import com.blb.service.impl.UserServiceImpl;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.IOException;

@WebServlet("/login")

public class LoginServlet extends HttpServlet {

@Override

protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

//实例化 Service 对象

UserService userService = new UserServiceImpl();

//从 jsp 页面的请求获取用户名和密码

String username = req.getParameter("username");

String password = req.getParameter("password");

//实例化 User 对象

User user = new User(username,password);

//登录判断

boolean result = userService.login(user);

if (result){

req.setAttribute("username",username);

req.getRequestDispatcher("/toIndex").forward(req,resp);

}else {

req.setAttribute("msg","用户名或密码错误");

req.getRequestDispatcher("/login.jsp").forward(req,resp);

}

}

}

ToAddServlet.java

package com.blb.servlet;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.IOException;

@WebServlet("/toAdd")

public class ToAddServlet extends HttpServlet {

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

resp.sendRedirect("/User_demo_war_exploded/add.jsp");

}

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ToRegisterServlet.java

package com.blb.servlet;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.IOException;

@WebServlet("/toRegister")

public class ToRegisterServlet extends HttpServlet {

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

resp.sendRedirect("/User_demo_war_exploded/register.jsp");

}

}

JSP 页面

添加用户：

<html>

<head>

<title>Title</title>

</head>

<body>

${msg}

<form action="doAdd">

姓名：<input type="text" name="empName"><br>

部门：<select name="deptName">

<option>人力资源</option>

<option selected>市场</option>

<option>财务</option>

<option>研发部</option>

</select>

<input type="submit" value="添加">

</form>

</body>

</html>

首页：

<html>

<head>

<title>$Title$</title>

</head>

<body>

${msg}

<table border="1" cellpadding="0" cellspacing="0">

<tr>

<th>员工编号</th>

<th>姓名</th>

<th>部门名称</th>

<th>操作</th>

</tr>

<c:forEach items="${emps}" var="emp">