一、项目先容
该项目是基于JavaWeb实现的学生管理系统,使用maven进行管理jar包,能够对学生信息进行增删改查,分页查询,以及实现管理员的注册、登录
数据库:MySQL
开发工具:idea
开发环境:jdk 1.8 + tomcat
二、项目结构
三、前期准备
1.配置maven环境,在pom.xml配置文件中配置项目所依靠的jar包
- <dependency>
- <groupId>mysql</groupId>
- <artifactId>mysql-connector-java</artifactId>
- <version>8.0.21</version>
- </dependency>
- <dependency>
- <groupId>javax.servlet</groupId>
- <artifactId>javax.servlet-api</artifactId>
- <version>3.0.1</version>
- <scope>provided</scope>
- </dependency>
- <dependency>
- <groupId>javax.servlet.jsp</groupId>
- <artifactId>jsp-api</artifactId>
- <version>2.2</version>
- <scope>provided</scope>
- </dependency>
复制代码 2.在MySql数据库中,创建登录注册表login和学生信息表student
(1)登录注册表login
(2)学生信息表student
(3)创建数据表代码
- SET NAMES utf-8;
- CREATE DATABASE studentManager;
- USE studentManager;
- CREATE TABLE student
- (
- sno INT PRIMARY KEY,
- sname VARCHAR(20) NOT NULL,
- sex CHAR(4) ,
- age INT DEFAULT 20,
- phone VARCHAR(30)
- );
- INSERT INTO student VALUES(1001,'jack','男',23,'13389076524');
- INSERT INTO student VALUES(1002,'rose','女',23,'18760987543');
- INSERT INTO student VALUES(1003,'tom','男',23,'13389067823');
- INSERT INTO student VALUES(1004,'王麻子','男',23,'13560738947');
- INSERT INTO student VALUES(1005,'大麻子','男',23,'18899067532');
- INSERT INTO student VALUES(1006,'小麻子','男',23,'15678634789');
- INSERT INTO student VALUES(1007,'老麻子','男',23,'12199834572');
- INSERT INTO student VALUES(1008,'张三','男',23,'15533098843');
- INSERT INTO student VALUES(1009,'长萨珊','女',23,'12209835679');
- INSERT INTO student VALUES(1010,'李四','女',23,'15509087635');
- INSERT INTO student VALUES(1011,'王五','男',23,'15788679043');
- INSERT INTO student VALUES(1012,'赵六','女',23,'12489034506');
- INSERT INTO student VALUES(1013,'刘二','男',23,'13560596743');
- CREATE TABLE login
- (
- uid INT PRIMARY KEY,
- pwd VARCHAR(20) NOT NULL,
- );
- INSERT INTO login VALUES(1, '1234');
- INSERT INTO login VALUES(2, '2222');
- INSERT INTO login VALUES(3, '6688');
复制代码 3.配置tocamt
四、代码实现
1.JSP界面实现
(1)首页-登录界面 (index.jsp)
(2)用户注册界面 (register.jsp)
(3)登录乐成-主界面 (main.jsp)
- <%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
- <%@ page import="com.stu.po.Student" %>
- <!DOCTYPE html>
- <html >
- <head>
- <title>学生信息管理平台</title>
- <style>
- .titleDiv{
- height: 85px;
- color:white;
- padding-top: 30px;
- font-size: 50px;
- padding-left: 30px;
- font-family: 隶书;
- }
- .mainDiv{
- width: 899px;
- height: 500px;
- border: 4px rgb(237, 237, 237) solid;
- border-radius: 5px;
- background-image: url("https://img1.baidu.com/it/u=4271373647,1745018175&fm=253&fmt=auto&app=138&f=JPEG?w=889&h=500");
- margin: auto;
- margin-top: 50px;
- background-size: auto;
- }
- .Navigation{
- width: 899px;
- height: 200px;
- background-color:#59c2c5;
- opacity:0.8;
- text-align: center;
- line-height: 200px;
- font-family: 楷体;
- }
- a{
- font-size:30px;
- color:whitesmoke;
- padding-left:20px;
- text-decoration: none;
- }
- a:hover{
- color: blue;
- font-family: 隶书;
- }
- </style>
- </head>
- <body>
- <div class="mainDiv">
- <div class="titleDiv">欢迎进入学生信息管理平台</div>
- <%
- if(session.getAttribute("login") == null) {
- session.setAttribute("loginErrorMessage", "您必须先登录才能访问主页!");
- response.sendRedirect("index.jsp");
- }
- %>
- <div class="Navigation">
- <a href="addStudent.jsp">添加学生</a>
- <a href="ShowStudentsByPageServlet">分页查询</a>
- <a href="ShowAllStudentsServlet">查看所有学生信息</a>
- <a href="QuitServlet">退出登录</a>
- </div>
- </div>
- </body>
- </html>
复制代码 (4)添加学生界面 (addStudent.jsp)
(5)分页查询界面(showAllStudentByPageNo.jsp)
(6)查察全部学生信息界面
(7) 修改学生界面 (updateStudent.jsp)
2.JavaBean实体类封装数据
(1)学生信息类 (Student.java)
- package com.stu.po;
- public class Student {
- //这是一个实体类,javabean
- private int sno;
- private String sname;
- private String sex;
- private int age;
- private String phone;
- public Student(int sno, String sname, String sex, int age, String phone) {
- this.sno = sno;
- this.sname = sname;
- this.sex = sex;
- this.age = age;
- this.phone = phone;
- }
- public Student() {
- }
- public int getSno() {
- return sno;
- }
- public void setSno(int sno) {
- this.sno = sno;
- }
- public String getSname() {
- return sname;
- }
- public void setSname(String sname) {
- this.sname = sname;
- }
- public String getSex() {
- return sex;
- }
- public void setSex(String sex) {
- this.sex = sex;
- }
- public int getAge() {
- return age;
- }
- public void setAge(int age) {
- this.age = age;
- }
- public String getPhone() {
- return phone;
- }
- public void setPhone(String phone) {
- this.phone = phone;
- }
- }
复制代码 (2)分页帮助类 (Page.java)
- package com.stu.po;
- import java.util.List;
- //分页帮助类
- public class Page {
- private int currentPage; //当前页面
- private int pageSize; //一页有多少条数据
- private int totalCount; //一共有多少条数据
- private int totalPage; //一共有多少页
- private List<Student> student;
- public Page() {
- }
- public Page(int currentPage, int pageSize, int totalCount, int totalPage, List<Student> student) {
- this.currentPage = currentPage;
- this.pageSize = pageSize;
- this.totalCount = totalCount;
- this.totalPage = totalPage;
- this.student = student;
- }
- public int getCurrentPage() {
- return currentPage;
- }
- public void setCurrentPage(int currentPage) {
- this.currentPage = currentPage;
- }
- public int getPageSize() {
- return pageSize;
- }
- public void setPageSize(int pageSize) {
- this.pageSize = pageSize;
- }
- public int getTotalCount() {
- return totalCount;
- }
- public void setTotalCount(int totalCount) {
- this.totalCount = totalCount;
- }
- public int getTotalPage() {
- return totalPage;
- }
- public void setTotalPage(int totalPage) {
- this.totalPage = totalPage;
- }
- public List<Student> getStudent() {
- return student;
- }
- public void setStudent(List<Student> student) {
- this.student = student;
- }
- }
复制代码 (3)JDBC工具类 (DBTools.java)
- package com.stu.utils;
- public interface DBTools {
- public static final String DRIVER_CLASS = "com.mysql.jdbc.Driver";
- public static final String CONN_STR = "jdbc:mysql://localhost:3306/studentmanager?userSSL=false&serverTimezone=Asia/Shanghai";
- public static final String USRENAME = "root";
- public static final String PWD = "123456";
- }
复制代码 3.三层架构
(1)表示层servlet
① 用户登录表示层 (LoginServlet.java)
- package com.stu.servlet;
- import java.io.IOException;
- 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 com.stu.po.Student;
- import com.stu.service.StudentService;
- import com.stu.service.StudentServiceImpl;
- @WebServlet("/LoginServlet")
- public class LoginServlet extends HttpServlet{
- @Override
- protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
- this.doPost(req, resp);
- }
- @Override
- protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
- StudentService service = new StudentServiceImpl();
- HttpSession session = request.getSession();
- if (session.getAttribute("loginErrorMessage") != null) {
- session.invalidate();
- }
- String uid = request.getParameter("uid");
- String pwd = request.getParameter("pwd");
- int _uid = Integer.parseInt(uid);
- boolean result = service.login(_uid, pwd);
- if(result){
- session.setAttribute("login", "log");
- response.sendRedirect("main.jsp");
- }else{
- response.sendRedirect("index.jsp");
- }
- }
- }
复制代码 ② 用户注册表示层 (RegisterServlet.java)
- package com.stu.servlet;
- import java.io.IOException;
- 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 com.stu.po.Student;
- import com.stu.service.StudentService;
- import com.stu.service.StudentServiceImpl;
- @WebServlet("/RegisterServlet")
- public class RegisterServlet extends HttpServlet{
- @Override
- protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
- this.doPost(req, resp);
- }
- @Override
- protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
- StudentService service = new StudentServiceImpl();
- String uid = request.getParameter("uid");
- String pwd = request.getParameter("pwd");
- int _uid = Integer.parseInt(uid);
- boolean result = service.addLogin(_uid,pwd);
- if(!result) {
- request.setAttribute("register", "reg");
- request.getRequestDispatcher("index.jsp").forward(request, response);
- }else {
- request.getRequestDispatcher("register.jsp").forward(request, response);
- }
- }
- }
复制代码 ③ 分页查询表示层 (ShowStudentsByPageServlet.java)
- package com.stu.servlet;
- import java.io.IOException;
- import java.util.List;
- 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 com.stu.po.Page;
- import com.stu.po.Student;
- import com.stu.service.StudentService;
- import com.stu.service.StudentServiceImpl;
- @WebServlet("/ShowStudentsByPageServlet")
- public class ShowStudentsByPageServlet extends HttpServlet{
- @Override
- protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
- StudentService Service = new StudentServiceImpl();
- int count = Service.getTotalCount();
- Page page = new Page();
- String currentPage = request.getParameter("currentPage");
- if(currentPage == null) {
- currentPage = "0";
- }
- int _currentPage = Integer.parseInt(currentPage);
- page.setCurrentPage(_currentPage);
- int totalCount = Service.getTotalCount();
- page.setTotalCount(totalCount);
- int pageSize = 5;
- int totalPage = (totalCount / pageSize) + 1;
- page.setTotalPage(totalPage+1);
- page.setPageSize(pageSize);
- List<Student> student = Service.queryStudentsByPageNo(_currentPage, pageSize);
- page.setStudent(student);
- request.setAttribute("page1", page);
- request.getRequestDispatcher("showAllStudentsByPageNo.jsp").forward(request, response);
- }
- }
复制代码 ④ 查询所学生信息表示层 (ShowAllStudentsServlet.java)
- package com.stu.servlet;
- import java.io.IOException;
- import java.util.List;
- 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 com.stu.po.Student;
- import com.stu.service.StudentService;
- import com.stu.service.StudentServiceImpl;
- @WebServlet("/ShowAllStudentsServlet")
- public class ShowAllStudentsServlet extends HttpServlet{
- @Override
- protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
- StudentService service = new StudentServiceImpl();
- HttpSession session = request.getSession();
- List<Student> allStudents = service.getAllStudents();
- session.setAttribute("allStudents", allStudents);
- response.sendRedirect("showAllStudents.jsp");
- }
- }
复制代码 ⑤ 添加学生表示层 (AddServlet.java)
- package com.stu.servlet;
- import com.stu.po.Student;
- import com.stu.service.StudentService;
- import com.stu.service.StudentServiceImpl;
- 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("/AddServlet")
- public class AddServlet extends HttpServlet{
- @Override
- protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
- this.doPost(req, resp);
- }
- @Override
- protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
- StudentService service = new StudentServiceImpl();
- String sno = request.getParameter("sno");
- String sname = request.getParameter("sname");
- String sex = request.getParameter("sex");
- String age = request.getParameter("age");
- String phone = request.getParameter("phone");
- int _sno = 0;
- if(sno != null || "".equals(sno)){
- _sno = Integer.parseInt(sno);
- }
- int _age = 0;
- if (age !=null || "".equals(age)){
- _age = Integer.parseInt(age);
- }
- Student s = new Student(_sno, sname, sex, _age, phone);
- int result = service.addStudent(s);
- HttpSession session = request.getSession();
- session.setAttribute("student", "stu");
- response.sendRedirect("main.jsp");
- }
- }
复制代码 ⑥ 删除学生表示层 (DeleteServlet.java)
- package com.stu.servlet;
- import com.stu.po.Student;
- import com.stu.service.StudentService;
- import com.stu.service.StudentServiceImpl;
- 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("/DeleteServlet")
- public class DeleteServlet extends HttpServlet {
- protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
- //1.获取sno
- String sno = request.getParameter("sno");
- int _sno = 0;
- if(sno != null && !"".equals(sno)){
- _sno = Integer.parseInt(sno);
- }
- //2.执行删除
- StudentService service = new StudentServiceImpl();
- Student stu = service.deleteStudent(_sno);
- //3.跳转到列表页
- request.setAttribute("stu", stu);
- request.getRequestDispatcher("ShowAllStudentsServlet").forward(request,response);
- }
- }
复制代码 ⑦ 根据学号查询学生信息表示层 (QueryStudentBySnoSevlet.java)
- package com.stu.servlet;
- import com.stu.po.Student;
- import com.stu.service.StudentService;
- import com.stu.service.StudentServiceImpl;
- 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("/QueryStudentBySnoServlet")
- public class QueryStudentBySnoServlet extends HttpServlet {
- @Override
- protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
- //获取sno;
- String sno = request.getParameter("sno");
- int _sno = 0;
- if(sno != null && !"".equals(sno)){
- _sno = Integer.parseInt(sno);
- }
- //2.查询学生数据
- StudentService service = new StudentServiceImpl();
- Student student = service.queryStudentBySno(_sno);
- //3.显示数据
- //存数据
- request.setAttribute("student", student);
- //跳转
- request.getRequestDispatcher("updateStudent.jsp").forward(request,response);
- }
- }
复制代码 ⑧ 修改学生信息表示层 (UpdateServlet.java)
- package com.stu.servlet;
- import com.stu.po.Student;
- import com.stu.service.StudentService;
- import com.stu.service.StudentServiceImpl;
- 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("/UpdateServlet")
- public class UpdateServlet extends HttpServlet {
- protected void doGet(HttpServletRequest request, HttpServletResponse resp) throws ServletException, IOException {
- String sno = request .getParameter("sno");
- String sname = request.getParameter("sname");
- String sex = request.getParameter("sex");
- String age = request.getParameter("age");
- String phone = request.getParameter("phone");
- int _sno = 0;
- if(sno != null && !"".equals(sno)){
- _sno = Integer.parseInt(sno);
- }
- int _age = 0;
- if(age != null && !"".equals(age)){
- _age = Integer.parseInt(age);
- }
- Student stu = new Student(_sno, sname, sex, _age, phone);
- StudentService service = new StudentServiceImpl();
- service.updateStudentBySno(_sno,stu);
- //3.跳转界面
- request.getRequestDispatcher("ShowAllStudentsServlet").forward(request, resp);
- }
- }
复制代码 ⑨ 退出登录表示层 (QuitServlet.java)
- package com.stu.servlet;
- import java.io.IOException;
- 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;
- @WebServlet("/QuitServlet")
- public class QuitServlet extends HttpServlet{
- @Override
- protected void doGet(HttpServletRequest request, HttpServletResponse resp) throws ServletException, IOException {
- HttpSession session = request.getSession();
- session.invalidate();//清空session对象中的所有属性数据内容
- resp.sendRedirect("index.jsp");
- }
- }
复制代码 (2)业务逻辑层service
① Service接口(StudentService.java)
- package com.stu.service;
- import java.util.List;
- import com.stu.po.Student;
- public interface StudentService {
- //service表示业务逻辑层,定义的每一个方法实际上对应的就是用户的一个需求(请求)
- public boolean login(int uid,String pwd);
- public boolean addLogin(int uid, String pwd);
- public List<Student> getAllStudents();
- public List<Student> queryStudentsByPageNo(int current, int pageSize);
- public Student deleteStudent(int sno);
- public Student queryStudentBySno(int sno);
- public int updateStudentBySno(int sno, Student stu) ;
- public int getTotalCount();
- public int addStudent(Student student);
-
- }
复制代码 ② 接口的实现类(StudentServiceImpl.java)
- package com.stu.service;
- import java.util.List;
- import com.stu.dao.StudentDao;
- import com.stu.dao.StudentDaoImpl;
- import com.stu.po.Student;
- public class StudentServiceImpl implements StudentService {
- StudentDao dao = new StudentDaoImpl();
- //登陆
- @Override
- public boolean login(int uid, String pwd) {
- return dao.login(uid, pwd);
- }
- // 注册
- @Override
- public boolean addLogin(int uid, String pwd){
- return dao.addLogin(uid, pwd);
- }
- // 查询所有学生
- @Override
- public List<Student> getAllStudents() {
- return dao.getAllStudents();
- }
- // 分页查询
- @Override
- public List<Student> queryStudentsByPageNo(int current, int pageSize) {
- return dao.queryStudentByPage(current,pageSize);
- }
- // 删除学生
- @Override
- public Student deleteStudent(int sno){
- return dao.deleteStudent(sno);
- }
- // 修改学生信息,要先根据学号查询学生信息
- public Student queryStudentBySno(int sno) {
- return dao.queryStudentBySno(sno);
- }
- //更改学生信息
- public int updateStudentBySno(int sno, Student stu) {
- return dao.updateStudentBySno(sno,stu);
- }
-
- //查询总条数
- @Override
- public int getTotalCount() {
- return dao.getTotalCount();
- }
- @Override
- public int addStudent(Student student) {
- return dao.addStudent(student);
- }
-
- }
复制代码 (3)数据访问层dao
① 接口(StudentDao.java)
- package com.stu.dao;
- import java.util.List;
- import com.stu.po.Student;
- public interface StudentDao {
- public boolean login(int uid ,String pwd);
- public boolean addLogin(int uid, String pwd);
- public List<Student> getAllStudents();
- public List<Student> queryStudentByPage(int currentPage,int pageSize);
- public Student deleteStudent(int sno);
- public Student queryStudentBySno(int sno);
- public int updateStudentBySno(int sno,Student stu);
- //查询总数据数
- public int getTotalCount();
- public int addStudent(Student student);
-
- }
复制代码 ② 接口的实现类(StudentDaoImpl.java)
- package com.stu.dao;
- import java.sql.Connection;
- import java.sql.DriverManager;
- import java.sql.ResultSet;
- import java.sql.SQLException;
- import java.sql.Statement;
- import java.util.ArrayList;
- import java.util.List;
- import com.stu.po.Student;
- import com.stu.utils.DBTools;
- public class StudentDaoImpl implements StudentDao {
- Connection conn = null; // 连接对象
- Statement st = null; // 语句对象
- ResultSet rs = null; // 结果集合对象
- @Override
- public boolean login(int uid, String pwd) {
- // 在这里需要连接数据库,根据int sno, String pwd这两个参数来查询student表
- // jdbc
- // 1:配置环境,下载数据库连接驱动jar文件,拷贝到项目中来
- // 2:加载驱动,根据驱动创建数据库的连接对象
- try {
- Class.forName(DBTools.DRIVER_CLASS);// 加载驱动
- conn = DriverManager.getConnection(DBTools.CONN_STR, DBTools.USRENAME, DBTools.PWD);
- // 3:执行sql语句,完成对数据库中表的数据的增删该查。必须创建一个语句对象(执行sql语句的)
- st = conn.createStatement();
- int count = 0;
- String sqlStr = "select * from login where uid =" + uid + " and pwd = '" + pwd + "'";
- rs = st.executeQuery(sqlStr);
- while(rs.next()) {
- count++;
- }
- if(count>0)
- return true;
- else
- return false;
- } catch (ClassNotFoundException e) {
- e.printStackTrace();
- } catch (SQLException e) {
- e.printStackTrace();
- }
- return false;
- }
- @Override
- public List<Student> getAllStudents() {
- try {
- Class.forName(DBTools.DRIVER_CLASS);// 加载驱动
- conn = DriverManager.getConnection(DBTools.CONN_STR, DBTools.USRENAME, DBTools.PWD);
- // 3:执行sql语句,完成对数据库中表的数据的增删该查。必须创建一个语句对象(执行sql语句的)
- st = conn.createStatement();
- String sqlStr = "select * from student";
- rs = st.executeQuery(sqlStr);
- List<Student> allStudents = new ArrayList<Student>();
- while (rs.next()) {
- int _sno = rs.getInt(1);
- String _sname = rs.getString(2);
- String _sex = rs.getString(3);
- int _age = rs.getInt(4);
- String _phone = rs.getString(5);
- Student s = new Student(_sno, _sname, _sex, _age, _phone);
- allStudents.add(s);
- }
- return allStudents;
- } catch (ClassNotFoundException e) {
- e.printStackTrace();
- } catch (SQLException e) {
- e.printStackTrace();
- }
- return null;
- }
- public List<Student> queryStudentByPage(int current, int pageSize) {
- try {
- Class.forName(DBTools.DRIVER_CLASS);// 加载驱动
- conn = DriverManager.getConnection(DBTools.CONN_STR, DBTools.USRENAME, DBTools.PWD);
- // 3:执行sql语句,完成对数据库中表的数据的增删该查。必须创建一个语句对象(执行sql语句的)
- st = conn.createStatement();
- int startPosition = current * pageSize;
- String sqlStr = "select * from student limit " + startPosition + "," + pageSize;
- rs = st.executeQuery(sqlStr);
- List<Student> allStudents = new ArrayList<Student>();
- while (rs.next()) {
- int _sno = rs.getInt(1);
- String _sname = rs.getString(2);
- String _sex = rs.getString(3);
- int _age = rs.getInt(4);
- String _phone = rs.getString(5);
- Student s = new Student(_sno, _sname, _sex, _age, _phone);
- allStudents.add(s);
- }
- return allStudents;
- } catch (ClassNotFoundException e) {
- e.printStackTrace();
- } catch (SQLException e) {
- e.printStackTrace();
- }
- return null;
- }
- public int getTotalCount() {//查询总数据数
- try {
- Class.forName(DBTools.DRIVER_CLASS);// 加载驱动
- conn = DriverManager.getConnection(DBTools.CONN_STR, DBTools.USRENAME, DBTools.PWD);
- // 3:执行sql语句,完成对数据库中表的数据的增删该查。必须创建一个语句对象(执行sql语句的)
- st = conn.createStatement();
- String sql = "select count(*) from student";
- rs = st.executeQuery(sql);
- while (rs.next()){
- int totalCount = rs.getInt(1);
- }
- }catch (Exception e){
- e.printStackTrace();
- }
- return 0;
- }
- @Override
- public int addStudent(Student student) {
- try {
- Class.forName(DBTools.DRIVER_CLASS);// 加载驱动
- conn = DriverManager.getConnection(DBTools.CONN_STR, DBTools.USRENAME, DBTools.PWD);
- st = conn.createStatement();
- String sqlStr = "insert into student values("+student.getSno()+",'" + student.getSname()+ "','" + student.getSex() +"',"+student.getAge()+",'"+student.getPhone()+"')";
- System.out.println(sqlStr);
- int result = st.executeUpdate(sqlStr);
- } catch (ClassNotFoundException e) {
- e.printStackTrace();
- } catch (SQLException e) {
- e.printStackTrace();
- }
- return 0;
- }
- @Override
- public boolean addLogin(int uid, String pwd) {
- try {
- Class.forName(DBTools.DRIVER_CLASS);// 加载驱动
- conn = DriverManager.getConnection(DBTools.CONN_STR, DBTools.USRENAME, DBTools.PWD);
- st = conn.createStatement();
- String sqlStr = "insert into login values(" + uid + ",'" + pwd + "')";
- int result = st.executeUpdate(sqlStr);
- } catch (ClassNotFoundException e) {
- e.printStackTrace();
- } catch (SQLException e) {
- e.printStackTrace();
- }
- return false;
- }
- @Override
- public Student deleteStudent(int sno) {
- try {
- Class.forName(DBTools.DRIVER_CLASS);// 加载驱动
- conn = DriverManager.getConnection(DBTools.CONN_STR, DBTools.USRENAME, DBTools.PWD);
- st = conn.createStatement();
- String sqlStr = "delete from student where sno = " + sno;
- System.out.println(sqlStr);
- int result = st.executeUpdate(sqlStr);
- } catch (Exception e){
- e.printStackTrace();
- }
- return null;
- }
- @Override
- public Student queryStudentBySno(int sno) {
- try {
- Class.forName(DBTools.DRIVER_CLASS);// 加载驱动
- conn = DriverManager.getConnection(DBTools.CONN_STR, DBTools.USRENAME, DBTools.PWD);
- st = conn.createStatement();
- String sqlStr = "select * from student where sno = "+ sno;
- rs = st.executeQuery(sqlStr);
- if (rs.next()) {
- int _sno = rs.getInt(1);
- String _sname = rs.getString(2);
- String _sex = rs.getString(3);
- int _age = rs.getInt(4);
- String _phone = rs.getString(5);
- Student s = new Student(_sno, _sname, _sex, _age, _phone);
- return s;
- }
- } catch (Exception e) {
- e.printStackTrace();
- }
- return null;
- }
- @Override
- public int updateStudentBySno(int sno, Student stu){
- try {
- Class.forName(DBTools.DRIVER_CLASS);// 加载驱动
- conn = DriverManager.getConnection(DBTools.CONN_STR, DBTools.USRENAME, DBTools.PWD);
- st = conn.createStatement();
- String sql = "update student set sname= '"+stu.getSname()+"', sex='"+stu.getSex()+"', age="+stu.getAge()+", phone='"+stu.getPhone()+"' where sno="+sno;
- System.out.println(sql);
- int result = st.executeUpdate(sql);
- } catch (Exception e){
- e.printStackTrace();
- }
- return 0;
- }
- }
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