JavaWeb阶段案例--简易版管理图书系统（增删改查）
1. 创建数据库及数据表
#创建数据库jdbc
CREATE DATABASE jdbc ;
#打开数据库
USE jdbc ;
#创建用户表 t_user
CREATE TABLE t_user(
id int PRIMARY KEY auto_increment,
username VARCHAR(20),
password VARCHAR(20),
sex VARCHAR(2),
hobby VARCHAR(20),
city VARCHAR(20),
signature VARCHAR(200)
);
#创建图书表 t_book
CREATE TABLE t_book(
id int PRIMARY KEY auto_increment,
bookname VARCHAR(20),
price FLOAT ,
author VARCHAR(20)
);
#在两个表中插入分别插入一条数据
INSERT INTO t_user VALUES(NULL,'admin','123','男','足球','济南','我是admin');
INSERT INTO t_book VALUES(NULL,'JavaWeb教程','50','李四');2.在idea中创建一个JavaWeb项目
- 在WEB-INF下创建一个lib包，并导入以下jar包：（导入后，鼠标右键选中lib文件夹，单击“add as lib...”
注：使用Lombok包时，除了需要导入jar包还需要从idea中下载Lombok插件
- file -- setting -- plugins -- 搜Lombok -- 勾选上 -- Apply -- OK
- file -- setting -- Build Exec..... -- Compiler -- Annotation Processors -- 勾选Enable annotation processing
3.在web下创建4个jsp和1和html
- 4个jsp（addBook.jsp 、 bookList.jsp 、 index.jsp 、 updateBook.jsp）
- 1个html（register.html）
1. 创建addBook.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
添加图书
新增图书
欢迎您,${loginUser.username}
2. 创建bookList.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
图书列表
3. 创建index.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
登录
登录
错误! ${errmsg}
Tips:账号：admin 密码：123
4. 创建updateBook.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
修改图书
修改图书
欢迎您,${loginUser.username}
5. 创建register.html
注册
注册账号
4.在src下创建4个文件夹
- 创建controller文件夹 --放servlet文件
- 创建dao文件夹 --放interface接口 ------在dao下创建文件夹impl --放实现接口的方法
- 创建enity文件夹 --放对象类
- 创建util文件夹 --放定义的方法（例如：连接数据库的方法）
- 直接创建一个Test的Java类 --用于在控制台测试
1. 创建controller文件夹，并创建以下servlet
1.创建 addBookServlet
import com.individual.dao.BookDao;
import com.individual.dao.impl.BookDaoImpl;
import com.individual.enity.Book;
import org.apache.commons.beanutils.BeanUtils;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.util.Map;
@WebServlet(name = "AddBookServlet", value = "/addbookservlet")
public class AddBookServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//修改编码
request.setCharacterEncoding("UTF-8");
//获取表单数据
Book book = new Book();
Map map = request.getParameterMap();
try {
BeanUtils.populate(book,map);
//调用Dao中添加图书的方法
BookDao bookDao = new BookDaoImpl();
int row = bookDao.addBook(book);
if (row != 0){
//跳转到图书列表页
response.sendRedirect("querybookservlet");
}
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
}
}
2.创建 LoginServler
import com.individual.dao.UserDao;
import com.individual.dao.impl.UserDaoImpl;
import com.individual.enity.User;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
@WebServlet(name = "LoginServlet", value = "/loginservlet")
public class LoginServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//修改编码
request.setCharacterEncoding("UTF-8");
//接收表单传递的参数
String username = request.getParameter("username");
String password = request.getParameter("password");
//登陆界面的记住密码
String remeber = request.getParameter("remeber");
//构建成一个User的对象
User user = new User();
user.setUsername(username);
user.setPassword(password);
//调用Dao的登陆方法，验证能否登录
UserDao userDao = new UserDaoImpl() ;
User loginUser = userDao.login(user);
if (loginUser == null){
//登陆失败
request.setAttribute("errmsg","账号或密码错误");
request.getRequestDispatcher("index.jsp").forward(request,response);
}else {
//登陆成功
if (remeber != null){
//记住密码 -- 写Cookie
//账号
Cookie cookie_username = new Cookie("username", username);
cookie_username.setMaxAge(60*5);
response.addCookie(cookie_username);
//密码
Cookie cookie_password = new Cookie("password", password);
cookie_password.setMaxAge(60*5);
response.addCookie(cookie_password);
}else {
//删除密码 -- 删Cookie
Cookie[] cookies = request.getCookies();
for (Cookie cookie : cookies) {
if (cookie.getName().equals("username") || cookie.getName().equals("password")){
cookie.setMaxAge(0);
response.addCookie(cookie);
}
}
}
//创建session对象，保存用户的信息
HttpSession session = request.getSession();
session.setAttribute("loginUser",loginUser); //存入数据
response.sendRedirect("querybookservlet");
}
}
}
3.创建 QueryBookServlet
import com.individual.dao.BookDao;
import com.individual.dao.impl.BookDaoImpl;
import com.individual.enity.Book;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.util.List;
@WebServlet(name = "QueryBookServlet", value = "/querybookservlet")
public class QueryBookServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//查询所有图书信息
BookDao bookDao = new BookDaoImpl();
List allBooks = bookDao.getAllBooks();
//转发到bookList.jsp 显示
request.setAttribute("list",allBooks);
request.getRequestDispatcher("bookList.jsp").forward(request,response);
}
}
4.创建 RegisterServlet
import com.individual.dao.UserDao;
import com.individual.dao.impl.UserDaoImpl;
import com.individual.enity.User;
import org.apache.commons.beanutils.BeanUtils;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.util.Map;
@WebServlet(name = "RegisterServlet", value = "/registerservlet")
public class RegisterServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//修改编码
request.setCharacterEncoding("UTF-8");
//获取表单元素（方式1：）
String username = request.getParameter("username");
String password = request.getParameter("password");
String sex = request.getParameter("sex");
//多选框 -- 不同
String[] hobbies = request.getParameterValues("hobby");
String hobbyStr = "" ;
for (String hobby : hobbies) {
hobbyStr += hobby + " " ;
}
String city = request.getParameter("city");
String signature = request.getParameter("signature");
//封装成User对象
User user = new User(username, password, sex, hobbyStr, city, signature);
/*
//获取表单元素（方式2：BeanUtil (jar包：commons-logging-1.2.jar commons-dbutils-1.7.jar)）
//封装成User对象
User user = new User();
Map map = request.getParameterMap(); //多个单选处理封装
//多选框需要单独处理
String[] hobbies = request.getParameterValues("hobby");
String hobbyStr = "" ;
for (String hobby : hobbies) {
hobbyStr += hobby + " " ;
}
try {
BeanUtils.populate(user,map);
user.setHobby(hobbyStr); //封装进多个爱好选项
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
*/
//调用Dao中的注册方法
UserDao userDao = new UserDaoImpl();
int row = userDao.register(user);
//跳转到登陆界面
if (row != 0 ){
response.sendRedirect("index.jsp");
}else {
response.sendRedirect("register.html");
}
}
}
5. 创建 GetBookInfoByIdServlet
import com.individual.dao.BookDao;
import com.individual.dao.impl.BookDaoImpl;
import com.individual.enity.Book;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
@WebServlet(name = "GetBookInfoByIdServlet", value = "/getBookInfoById")
public class GetBookInfoByIdServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//修改编码
request.setCharacterEncoding("UTF-8");
//获取图书的id
int id = Integer.parseInt(request.getParameter("id"));
//根据图书的id，查询图书的信息
BookDao bookDao = new BookDaoImpl();
Book book = bookDao.getBookById(id);
//跳转到图书修改页面
request.setAttribute("book",book);
request.getRequestDispatcher("updateBook.jsp").forward(request,response);
}
}
6. 创建 UpateBookServlet
import com.individual.dao.BookDao;
import com.individual.dao.impl.BookDaoImpl;
import com.individual.enity.Book;
import org.apache.commons.beanutils.BeanUtils;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.util.Map;
@WebServlet(name = "UpateBookServlet", value = "/uptBook")
public class UpateBookServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//修改编码
request.setCharacterEncoding("UTF-8");
//获取页面上的图书信息（图书信息修改后的）
Map map = request.getParameterMap();
Book book = new Book();
try {
BeanUtils.populate(book,map);
//调用dao，执行修改图书功能
BookDao bookDao = new BookDaoImpl();
int row = bookDao.uptBook(book);
//调转回 图书列表页
if (row != 0){
response.sendRedirect("querybookservlet");
}
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
}
}
7.创建 DeleteBookServlet
import com.individual.dao.BookDao;
import com.individual.dao.impl.BookDaoImpl;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
@WebServlet(name = "DeleteBookServlet", value = "/delBook")
public class DeleteBookServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//获取图书id
int id = Integer.parseInt(request.getParameter("id"));
//调用dao中的删除图书的方法
BookDao bookDao = new BookDaoImpl();
int row = bookDao.dalBook(id);
//跳转回 列表页
if (row != 0){
response.sendRedirect("querybookservlet");
}
}
}
2. 创建dao文件夹并在dao下创建文件夹impl
1.在dao下创建interface文件 - BookDao
import com.individual.enity.Book;
import java.util.List;
public interface BookDao {
//查询所有图书
List getAllBooks();
//添加图书
int addBook(Book book);
//根据图书id，查询图书信息
Book getBookById(int id);
//修改图书
int uptBook(Book book);
//删除图书
int dalBook(int id);
}
2.在dao下创建interface文件 - UserDao
import com.individual.enity.User;
/*
UserDao :
数据存取对象 - 增删改查
*/
public interface UserDao {
User login(User user) ; //登陆方法
int register(User user) ; //注册方法
}3.在impl下创建Java文件 - BookDaoImpl
import com.individual.dao.BookDao;
import com.individual.enity.Book;
import com.individual.util.DBUtil;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import java.sql.SQLException;
import java.util.List;
public class BookDaoImpl implements BookDao {
QueryRunner qr = new QueryRunner();
@Override
public List getAllBooks() {
List list = null;
String sql = "select * from t_book" ;
try {
list = qr.query(DBUtil.getConn(),sql,new BeanListHandler<>(Book.class));
} catch (SQLException e) {
e.printStackTrace();
}
return list;
}
@Override
public int addBook(Book book) {
int row = 0 ;
String sql = "insert into t_book values(null,?,?,?)";
try {
row = qr.update(DBUtil.getConn(), sql, book.getBookname(), book.getPrice(), book.getAuthor());
} catch (SQLException e) {
e.printStackTrace();
}
return row;
}
@Override
public Book getBookById(int id) {
Book book = null ;
String sql = "select * from t_book where id = ?" ;
try {
book = qr.query(DBUtil.getConn(), sql, new BeanHandler<>(Book.class), id);
} catch (SQLException e) {
e.printStackTrace();
}
return book;
}
@Override
public int uptBook(Book book) {
int row = 0 ;
String sql = "update t_book set bookname = ? , price = ? , author = ? where id = ?";
try {
row = qr.update(DBUtil.getConn(), sql, book.getBookname(), book.getPrice(), book.getAuthor(), book.getId());
} catch (SQLException e) {
e.printStackTrace();
}
return row ;
}
@Override
public int dalBook(int id) {
int row = 0;
String sql = "delete from t_book where id = ?";
try {
row = qr.update(DBUtil.getConn(), sql, id);
} catch (SQLException e) {
e.printStackTrace();
}
return row;
}
}
4.在impl下创建Java文件 - UserDaoImpl
import com.individual.dao.UserDao;
import com.individual.enity.User;
import com.individual.util.DBUtil;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import java.sql.SQLException;
public class UserDaoImpl implements UserDao {
QueryRunner qr = new QueryRunner();
//登录
@Override
public User login(User user) {
User loginUser = null ;
String sql = "select * from t_user where username = ? and password = ?" ;
try {
loginUser = qr.query(DBUtil.getConn(), sql, new BeanHandler<>(User.class), user.getUsername(), user.getPassword());
} catch (SQLException e) {
e.printStackTrace();
}
return loginUser;
}
//注册
@Override
public int register(User user) {
int row = 0 ;
String sql = "insert into t_user values(null,?,?,?,?,?,?)" ;
try {
row = qr.update(DBUtil.getConn(), sql, user.getUsername(), user.getPassword(), user.getSex(), user.getHobby(),
user.getCity(), user.getSignature());
} catch (SQLException e) {
e.printStackTrace();
}
return row;
}
}
3. 创建enity文件夹
1.创建Java文件 - Book
/*
使用Lombok实体类
*/
import lombok.Data;
@Data
public class Book {
private int id ;
private String bookname;
private float price;
private String author;
}
2.创建Java文件 - User
/*
实体类（JavaBean）
*/
public class User {
private int id ;
private String username ;
private String password ;
private String sex ;
private String hobby ;
private String city ;
private String signature ;
public User() {
}
public User(String username, String password, String sex, String hobby, String city, String signature) {
this.username = username;
this.password = password;
this.sex = sex;
this.hobby = hobby;
this.city = city;
this.signature = signature;
}
public User(int id, String username, String password, String sex, String hobby, String city, String signature) {
this.id = id;
this.username = username;
this.password = password;
this.sex = sex;
this.hobby = hobby;
this.city = city;
this.signature = signature;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public String getHobby() {
return hobby;
}
public void setHobby(String hobby) {
this.hobby = hobby;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public String getSignature() {
return signature;
}
public void setSignature(String signature) {
this.signature = signature;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", username='" + username + '\'' +
", password='" + password + '\'' +
", sex='" + sex + '\'' +
", hobby='" + hobby + '\'' +
", city='" + city + '\'' +
", signature='" + signature + '\'' +
'}';
}
}
4. 创建util文件夹
1. 创建Java文件 - DBUtil
import java.sql.*;
/*
连接数据库的工具类
*/
public class DBUtil {
//1.获取数据库连接
public static Connection getConn(){
Connection conn = null;
//2.1 加载驱动
try {
Class.forName("com.mysql.cj.jdbc.Driver");
//2.2 获取连接
String url = "jdbc:mysql://localhost:3306/jdbc?useSSL=false&allowPublicKeyRetrieval=true&serverTimezone=UTC";
String user = "root"; //数据库的用户名
String password = "root"; //数据库的密码
conn = DriverManager.getConnection(url, user, password);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}
//2.释放资源
public static void closeAll(Connection conn, Statement stmt, ResultSet rs){
if (rs != null){
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (stmt != null){
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (conn != null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
5. 直接创建一个Test的Java类
1. 创建Java文件 - Test
import com.individual.dao.BookDao;
import com.individual.dao.impl.BookDaoImpl;
import com.individual.dao.impl.UserDaoImpl;
import com.individual.enity.Book;
import com.individual.enity.User;
import java.util.List;
import java.util.Scanner;
public class Test {
static Scanner sc = new Scanner(System.in) ;
public static void main(String[] args) {
// testLogin(); //验证登录
// testRegister(); //验证注册
// testQueryBook(); //验证查询所有图书
testAddBook(); //验证添加图书
}
private static void testAddBook() {
Book book = new Book();
book.setBookname("java");
book.setPrice(20);
book.setAuthor("曹操");
BookDao bookDao = new BookDaoImpl();
int row = bookDao.addBook(book);
if (row != 0){
System.out.println("图书添加成功");
}
}
private static void testQueryBook() {
BookDao bookDao = new BookDaoImpl();
List books = bookDao.getAllBooks();
for (Book book : books) {
System.out.println(book);
}
}
private static void testRegister() {
System.out.println("请输入账号：");
String username = sc.next();
System.out.println("请输入密码：");
String password = sc.next();
System.out.println("请输入性别：");
String sex = sc.next();
System.out.println("请输入爱好：");
String hobby = sc.next();
System.out.println("请输入城市：");
String city = sc.next();
System.out.println("请输入个性签名：");
String signature = sc.next();
//构建User对象
User user = new User(username, password, sex, hobby, city, signature);
//调用Dao的注册方法
UserDaoImpl userDao = new UserDaoImpl();
int row = userDao.register(user) ;
if (row != 0){
System.out.println("注册成功");
}else {
System.out.println("注册失败");
}
}
private static void testLogin() {
//验证登录
System.out.println("请输入账号：");
String username = sc.next();
System.out.println("请输入密码：");
String password = sc.next();
User user = new User();
user.setUsername("username");
user.setPassword("password");
UserDaoImpl userDao = new UserDaoImpl();
User loginUser = userDao.login(user);
if (loginUser == null){
System.out.println("登录失败");
}else {
System.out.println("登陆成功");
}
}
}
---------------------------------------------------- 改进版 --------------------------------------------------
新增技术：使用 Filter过滤器 、数据库连接池
Filter过滤器（访问路径过滤器、修改编码过滤器）：
访问路径过滤器：
在src下新建一个包，名为： filter
在这个包下创建名为： AuthorFilter 的Filter文件
import com.individual.enity.User;
import javax.servlet.*;
import javax.servlet.annotation.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
@WebFilter(filterName = "AuthorFilter",urlPatterns = "/*")
public class AuthorFilter implements Filter {
public void init(FilterConfig config) throws ServletException {
}
public void destroy() {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws ServletException, IOException {
HttpServletRequest request1 = (HttpServletRequest) request;
HttpServletResponse response1 = (HttpServletResponse) response;
//可直接放行的资源路径
String uris[] = {
"/ch07/",
"/ch07/index.jsp",
"/ch07/loginservlet",
"/ch07/addBook.jsp",
};
//有一些资源可直接放行（登录页、验证页、首页）
String requestURI = request1.getRequestURI();
if (checkURI(uris,requestURI)){
chain.doFilter(request, response);
return;
}
//判断用户是否登录
HttpSession session = request1.getSession();
User loginUser = (User) session.getAttribute("loginUser");
if (loginUser != null){
//已登录，放行
chain.doFilter(request, response);
}else {
//未登录，重定向到登录页
response1.sendRedirect("index.jsp");
}
}
//验证哪些资源可直接放行
public boolean checkURI(String uris[],String requestUri){
boolean flag = false;
for (String s : uris) {
if (requestUri.equals(s)){
flag = true;
}
}
return flag;
}
}
修改编码过滤器：
在filter包下创建名为： EncodingFilter 的Filter文件
import javax.servlet.*;
import javax.servlet.annotation.*;
import java.io.IOException;
@WebFilter(filterName = "EncodingFilter",urlPatterns = "/*")
public class EncodingFilter implements Filter {
public void init(FilterConfig config) throws ServletException {
}
public void destroy() {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws ServletException, IOException {
//修改编码
request.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=UTF-8");
chain.doFilter(request, response);
}
}
（此时就可以将controller包下servlet文件中的修改编码代码删除）
数据库连接池
在src下新建下图所示配置文件
在lib文件夹下新添druid-1.1.12.jar
在util包下新建Java文件 ： DruidUtils
import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.pool.DruidDataSourceFactory;
import javax.sql.DataSource;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;
public class DruidUtils {
//Druid德鲁伊,据说是魔兽世界中的一个角色,森林女神
public static DruidDataSource dataSource;//数据库连接池
//1.初始化Druid连接池
static {
//第二种方式:使用软编码通过配置文件初始化
try {
Properties properties = new Properties();
//通过类加载器加载配置文件
InputStream inputStream = DruidUtils.class.getClassLoader().getResourceAsStream("druid.properties");
properties.load(inputStream);
//创建连接池
dataSource = (DruidDataSource) DruidDataSourceFactory.createDataSource(properties);
} catch (Exception e) {
e.printStackTrace();
}
}
//2.获取连接
public static Connection getConnection() {
try {
return dataSource.getConnection();//从连接池中获取连接
} catch (SQLException e) {
e.printStackTrace();
}
return null;
}
public static DataSource getDataSource(){
return dataSource;
}
//3.释放资源
public static void closeAll(Connection connection, Statement statement, ResultSet resultSet) {
//释放resultSet
try {
if (resultSet != null) {
resultSet.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
//释放Statement
try {
if (statement != null) {
statement.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
//释放Connection
try {
if (connection != null) {
connection.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
将dao包下的impl包中的BookDaoImpl文件改成：
import com.individual.dao.BookDao;
import com.individual.enity.Book;
import com.individual.util.DruidUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import java.sql.SQLException;
import java.util.List;
public class BookDaoImpl implements BookDao {
QueryRunner qr = new QueryRunner(DruidUtils.getDataSource());
@Override
public List getAllBooks() {
List list = null;
String sql = "select * from t_book" ;
try {
list = qr.query(sql,new BeanListHandler<>(Book.class));
} catch (SQLException e) {
e.printStackTrace();
}
return list;
}
@Override
public int addBook(Book book) {
int row = 0 ;
String sql = "insert into t_book values(null,?,?,?)";
try {
row = qr.update(sql, book.getBookname(), book.getPrice(), book.getAuthor());
} catch (SQLException e) {
e.printStackTrace();
}
return row;
}
@Override
public Book getBookById(int id) {
Book book = null ;
String sql = "select * from t_book where id = ?" ;
try {
book = qr.query(sql, new BeanHandler<>(Book.class), id);
} catch (SQLException e) {
e.printStackTrace();
}
return book;
}
@Override
public int uptBook(Book book) {
int row = 0 ;
String sql = "update t_book set bookname = ? , price = ? , author = ? where id = ?";
try {
row = qr.update(sql, book.getBookname(), book.getPrice(), book.getAuthor(), book.getId());
} catch (SQLException e) {
e.printStackTrace();
}
return row ;
}
@Override
public int dalBook(int id) {
int row = 0;
String sql = "delete from t_book where id = ?";
try {
row = qr.update(sql, id);
} catch (SQLException e) {
e.printStackTrace();
}
return row;
}
}
将dao包下的impl包中的UserDaoImpl文件改成：
import com.individual.dao.UserDao;
import com.individual.enity.User;
import com.individual.util.DruidUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import java.sql.SQLException;
public class UserDaoImpl implements UserDao {
QueryRunner qr = new QueryRunner(DruidUtils.getDataSource());
//登录
@Override
public User login(User user) {
User loginUser = null ;
String sql = "select * from t_user where username = ? and password = ?" ;
try {
loginUser = qr.query(sql, new BeanHandler<>(User.class), user.getUsername(), user.getPassword());
} catch (SQLException e) {
e.printStackTrace();
}
return loginUser;
}
//注册
@Override
public int register(User user) {
int row = 0 ;
String sql = "insert into t_user values(null,?,?,?,?,?,?)" ;
try {
row = qr.update(sql, user.getUsername(), user.getPassword(), user.getSex(), user.getHobby(),
user.getCity(), user.getSignature());
} catch (SQLException e) {
e.printStackTrace();
}
return row;
}
}
（此时，即可将util包中DBUtil文件删除）