练习-Java代码实现简单的图书管理系统
图书管理系统
- 1、需求
- 2、建表
- 3、log4j.properties
- 4、db.properties
- 5、PropertiesUtil
- 6、DBUtil
- 7、IRowMapper
- 8、PublisherManager
- 9、BookManager
- 10、Client
1、需求
已知如下两个表：
publisher id name(唯一) address
book id isbn name publisher_id
欢迎进入书籍管理系统
1、出版社管理：增、删（name）、改(name)、查（name）
2、书籍管理：增、删（name）、改(name)、查（name）
3、退出
2、建表
create table publisher(
id char(36) primary key,
name varchar(24) unique,
address varchar(120)
)
create table book(
id char(36) primary key,
isbn varchar(12) unique,
name varchar(24),
publisher_id char(36),
#外键约束
foreign key(publisher_id) references publisher(id)
)
3、log4j.properties
因为在控制台打印的信息有限，所以需要把相关的日志文件保存在一个日志文件中，便于查找问题
导入log4j的jar包并配置log4j.properties
# DEBUG设置输出日志级别，由于为DEBUG，所以ERROR、WARN和INFO 级别日志信息也会显示出来
log4j.rootLogger=DEBUG,Console,RollingFile
#将日志信息输出到控制台
log4j.appender.Console=org.apache.log4j.ConsoleAppender
log4j.appender.Console.layout=org.apache.log4j.PatternLayout
log4j.appender.Console.layout.ConversionPattern= [%-5p]-[%d{yyyy-MM-dd HH:mm:ss}] -%l -%m%n
#将日志信息输出到操作系统D盘根目录下的log.log文件中
log4j.appender.RollingFile=org.apache.log4j.DailyRollingFileAppender
log4j.appender.RollingFile.File=D://log.log
log4j.appender.RollingFile.layout=org.apache.log4j.PatternLayout
log4j.appender.RollingFile.layout.ConversionPattern=%d [%t] %-5p %-40.40c %X{traceId}-%m%n
4、db.properties
使用JDBC连接数据库的时候有时候需要修改连接的配置信息，如果每次修改都更改源代码不利于项目的维护，所以这里是使用db.properties文件把JDBC的配置信息保存在其中。
url=jdbc:mysql://127.0.0.1:3306/test
userName=root
password=root
5、PropertiesUtil
上面已经把数据库的相关配置信息保存在了db.properties文件中。我们使用一个PropertiesUtil类读取db.properties文件
/**
* 获取配置文件中的信息
*
* @author Administrator
*/
public class PropertiesUtil {
private static Properties properties = new Properties();
static {
InputStream inputStream = PropertiesUtil.class.getClassLoader().getResourceAsStream("db.properties");
try {
properties.load(inputStream);
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 获取配置信息
*
* @author Administrator
*/
public static String getValue(String key) {
return properties.getProperty(key);
}
}
6、DBUtil
在上面已经获得了数据库连接的配置信息，创建一个DBUtil类来对数据库进行增删改查。
/**
* 数据库连接工具类
*
* @author Administrator
*/
public class DBUtil {
public static Logger logger = Logger.getLogger(DBUtil.class);
static {
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
logger.debug(e.getMessage(), e);
}
}
/**
* 获取连接
*
* @author Administrator
*/
private static Connection getConnection() {
try {
String url = PropertiesUtil.getValue("url");
String userName = PropertiesUtil.getValue("userName");
String password = PropertiesUtil.getValue("password");
return DriverManager.getConnection(url, userName, password);
} catch (Exception e) {
logger.debug(e.getMessage(), e);
}
return null;
}
/**
* 工具类处理事务
*
* @author Administrator
*/
public static void transaction(String...sqls ) {
Connection connection = null;
Statement statement = null;
try {
connection = getConnection();
connection.setAutoCommit(false);
statement = connection.createStatement();
for (String sql : sqls) {
statement.addBatch(sql);
}
statement.executeBatch();
connection.commit();
} catch (SQLException e) {
if(connection!=null) {
try {
connection.rollback();
} catch (SQLException e1) {
logger.debug(e1.getMessage(), e1);
}
}
logger.debug(e.getMessage(), e);
}
}
/**
* 查询数据库是否存在特定数据
*
* @author Administrator
*/
public static boolean exist(String name, String sql) {
class RowMapper implements IRowMapper {
boolean state = false;
@Override
public void rowMapper(ResultSet resultSet) {
try {
while (resultSet.next()) {
state = true;
}
} catch (SQLException e) {
logger.debug(e.getMessage(), e);
}
}
}
RowMapper rowMapper = new RowMapper();
DBUtil.query(sql, rowMapper, name);
return rowMapper.state;
}
/**
* 查询（不能防止SQL注入）
*
* @author Administrator
*/
public static void query(String sql, IRowMapper rowMapper) {
Connection connection = null;
Statement statement = null;
ResultSet resultSet = null;
try {
connection = getConnection();
statement = connection.createStatement();
resultSet = statement.executeQuery(sql);
rowMapper.rowMapper(resultSet);
} catch (Exception e) {
logger.debug(e.getMessage(), e);
} finally {
close(resultSet, statement, connection);
}
}
/**
* 更改(不能防止SQL注入)
*
* @author Administrator
*/
public static boolean update(String sql) {
Connection connection = null;
Statement statement = null;
try {
connection = getConnection();
statement = connection.createStatement();
return statement.executeUpdate(sql) > 0;
} catch (Exception e) {
logger.debug(e.getMessage(), e);
} finally {
close(statement, connection);
}
return false;
}
/**
* 释放资源
*
* @author Administrator
*/
private static void close(Statement statement, Connection connection) {
try {
if (statement != null) {
statement.close();
}
} catch (SQLException e1) {
e1.printStackTrace();
}
try {
if (connection != null) {
connection.close();
}
} catch (SQLException e) {
logger.debug(e.getMessage(), e);
}
}
/**
* 释放资源
*
* @author Administrator
*/
private static void close(ResultSet resultSet, Statement statement, Connection connection) {
try {
if (resultSet != null) {
resultSet.close();
}
} catch (SQLException e) {
logger.debug(e.getMessage(), e);
}
close(statement, connection);
}
/**
* 更改数据数据，可以防止SQL注入
*
* @author Administrator
*/
public static boolean update(String sql, Object... params) {
Connection connection = null;
PreparedStatement preparedStatement = null;
try {
connection = getConnection();
preparedStatement = connection.prepareStatement(sql);
for (int i = 1; i <= params.length; i++) {
preparedStatement.setObject(i, params[i - 1]);
}
return preparedStatement.executeUpdate() > 0;
} catch (Exception e) {
logger.debug(e.getMessage(), e);
} finally {
close(preparedStatement, connection);
}
return false;
}
/**
* 查询数据库信息(防止SQL注入)
*
* @author Administrator
*/
public static void query(String sql, IRowMapper rowMapper, Object... params) {
Connection connection = null;
PreparedStatement preparedStatement = null;
ResultSet resultSet = null;
try {
connection = getConnection();
preparedStatement = connection.prepareStatement(sql);
for (int i = 1; i <= params.length; i++) {
preparedStatement.setObject(i, params[i - 1]);
}
resultSet = preparedStatement.executeQuery();
rowMapper.rowMapper(resultSet);
} catch (Exception e) {
logger.debug(e.getMessage(), e);
} finally {
close(resultSet, preparedStatement, connection);
}
}
}
7、IRowMapper
/**
* 实现JDBC查询数据库的接口
*
* @author Administrator
*/
public interface IRowMapper {
void rowMapper(ResultSet resultSet);
}
通过接口回调可以确保在ResultSet关闭之前操作ResultSet对象
8、PublisherManager
出版社管理系统具体代码实现
/**
* 出版社管理
*
* @author Administrator
*/
public class PublisherManager {
/**
* 出版社管理菜单
*
* @author Administrator
*/
public void publisherManagerMenu() {
System.out.println("1.增加出版社");
System.out.println("2.删除出版社");
System.out.println("3.修改出版社");
System.out.println("4.查询出版社");
Scanner scanner = new Scanner(System.in);
String choosePublisher = scanner.nextLine();
switch (choosePublisher) {
case "1": {
addPublisher();
break;
}
case "2": {
deletePublisher();
break;
}
case "3": {
updatePublisher();
break;
}
case "4": {
selectPublisher();
break;
}
default:
System.out.println("请输入1-4");
break;
}
}
/**
* 查询出版社
*
* @author Administrator
*/
private static void selectPublisher() {
System.out.println("请输入要查询的出版社名字");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
String sql = "select * from publisher where name = ?";
IRowMapper rowMapper = new IRowMapper() {
@Override
public void rowMapper(ResultSet resultSet) {
try {
if (resultSet.next()) {
System.out.println("出版社名" + resultSet.getString(2));
System.out.println("出版社地址" + resultSet.getString(3));
} else {
System.out.println("要查询的" + name + "出版社不存在");
}
} catch (SQLException e) {
e.printStackTrace();
}
}
};
DBUtil.query(sql, rowMapper, name);
}
/**
* 修改出版社
*
* @author Administrator
*/
private static void updatePublisher() {
System.out.println("请输入要修改的出版社名字");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
String sql = "select * from publisher where name = ?";
if (DBUtil.exist(name, sql)) {
System.out.println("请输入新的出版社名字");
String newName = scanner.nextLine();
if (!DBUtil.exist(newName, sql)) {
System.out.println("请输入新的出版社地址");
String newAddress = scanner.nextLine();
sql = "update publisher set name = ? ,address = ? where name=?";
if (DBUtil.update(sql, newName, newAddress, name)) {
System.out.println("修改成功");
}
} else {
System.out.println("出版社" + newName + "已经存在");
}
} else {
System.out.println(name + "的不存在");
}
}
/**
* 删除出版社
*
* @author Administrator
*/
private static void deletePublisher() {
System.out.println("请输入要删除的出版社名字");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
//因为book表中的publisher_id指向publisher表中的id
//所以在删除出版社的时候需要删除book表中对应该出版社的所有图书
String sql = "select id from publisher where name = ?";
if (DBUtil.exist(name, sql)) {
class RowMapper implements IRowMapper {
String id;
@Override
public void rowMapper(ResultSet resultSet) {
try {
if (resultSet.next()) {
id = resultSet.getString("id");
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
RowMapper rowMapper = new RowMapper();
DBUtil.query(sql, rowMapper, name);
String publishId = rowMapper.id;
sql = "delete from book where publisher_id = ?";
DBUtil.update(sql, publishId);
sql = "delete from publisher where name = ?";
if (DBUtil.update(sql, name)) {
System.out.println("删除成功");
}
} else {
System.out.println(name + "出版社不存在");
}
}
/**
* 添加出版社
*
* @author Administrator
*/
private static void addPublisher() {
System.out.println("请输入要添加的出版社的名字");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
String sql = "select id from publisher where name = ?";
if (DBUtil.exist(name, sql)) {
System.out.println(name + "出版社已经存在");
return;
}
System.out.println("请输入要添加的出版社的地址");
String address = scanner.nextLine();
sql = "insert publisher (id,name,address) values (?,?,?)";
String id = UUID.randomUUID().toString();
DBUtil.update(sql, id, name, address);
System.out.println("添加成功");
}
}
9、BookManager
书籍管理系统具体代码实现
/**
* 书籍管理
*
* @author Administrator
*/
public class BookManager {
/**
* 书籍管理菜单
*
* @author Administrator
*/
public void bookManagerMenu() {
System.out.println("1.增加图书");
System.out.println("2.删除图书");
System.out.println("3.修改图书");
System.out.println("4.查询图书");
Scanner scanner = new Scanner(System.in);
String choosebook = scanner.nextLine();
switch (choosebook) {
case "1": {
addBook();
break;
}
case "2": {
deleteBook();
break;
}
case "3": {
updateBook();
break;
}
case "4": {
selectBook();
break;
}
default:
System.out.println("请输入1-4");
break;
}
}
/**
* 查询书籍
*
* @author Administrator
*/
private static void selectBook() {
System.out.println("请输入要查询的图书的书名");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
String sql = "select * from book where name = ?";
class RowMapper implements IRowMapper {
String publisherId;
@Override
public void rowMapper(ResultSet resultSet) {
try {
if (resultSet.next()) {
System.out.println("书名" + name);
String isbn = resultSet.getString("isbn");
System.out.println("isbn" + isbn);
publisherId = resultSet.getString("publisher_id");
} else {
System.out.println(name + "不存在");
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
RowMapper rowMapper = new RowMapper();
DBUtil.query(sql, rowMapper, name);
if (rowMapper.publisherId != null) {
class RowMapperPublisher implements IRowMapper {
@Override
public void rowMapper(ResultSet resultSet) {
try {
if (resultSet.next()) {
String publisherName = resultSet.getString("name");
System.out.println("出版社" + publisherName);
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
sql = "select * from publisher where id = ?";
RowMapperPublisher rowMapperPublisher = new RowMapperPublisher();
DBUtil.query(sql, rowMapperPublisher, rowMapper.publisherId);
}
}
/**
* 修改书籍
*
* @author Administrator
*/
private static void updateBook() {
System.out.println("请输入要修改的图书的书名");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
String sql = "select * from book where name = ?";
if (DBUtil.exist(name, sql)) {
class RowMapper implements IRowMapper {
String publisherId;
@Override
public void rowMapper(ResultSet resultSet) {
try {
if (resultSet.next()) {
publisherId = resultSet.getString("publisher_id");
} else {
System.out.println(name + "不存在");
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
RowMapper rowMapper = new RowMapper();
DBUtil.query(sql, rowMapper, name);
if (rowMapper.publisherId != null) {
System.out.println("请输入新的出版社");
String publisherName = scanner.nextLine();
sql = "select * from publisher where name = ?";
class RowMapperPublisherForBook implements IRowMapper {
String rowMapperIdForPublisher;
boolean state = false;
@Override
public void rowMapper(ResultSet resultSet) {
try {
if (resultSet.next()) {
state = true;
rowMapperIdForPublisher = resultSet.getString("id");
} else {
System.out.println(publisherName + "出版社不存在");
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
RowMapperPublisherForBook rowMapperPublisherForBook = new RowMapperPublisherForBook();
DBUtil.query(sql, rowMapperPublisherForBook, publisherName);
if (rowMapperPublisherForBook.state) {
System.out.println("请输入新的ISBN");
String newIsbn = scanner.nextLine();
System.out.println("请输入新的书名");
String newName = scanner.nextLine();
sql = "update book set isbn=?,name=?,publisher_id=? where name = ?";
DBUtil.update(sql, newIsbn, newName, rowMapperPublisherForBook.rowMapperIdForPublisher, name);
System.out.println("修改成功");
}
}
} else {
System.out.println("要修改的书籍不存在");
}
}
/**
* 删除书籍
*
* @author Administrator
*/
private static void deleteBook() {
System.out.println("请输入要删除的图书的书名");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
String sql = "delete from book where name=?";
if (DBUtil.update(sql, name)) {
System.out.println("删除成功");
} else {
System.out.println("书名为" + name + "的书籍不存在");
}
}
/**
* 添加书籍
*
* @author Administrator
*/
private static void addBook() {
System.out.println("请输入要增加的图书的书名");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
String sql = "select id from book where name = ?";
if (DBUtil.exist(name, sql)) {
System.out.println(name + "图书已经存在");
return;
}
System.out.println("请输入要添加的书籍isbn");
String isbn = scanner.nextLine();
System.out.println("请输入要添加的图书所属的出版社");
String publisherName = scanner.nextLine();
String id = UUID.randomUUID().toString();
sql = "select id from publisher where name = ?";
class RowMapper implements IRowMapper {
String publisher_id;
@Override
public void rowMapper(ResultSet resultSet) {
try {
if (resultSet.next()) {
publisher_id = resultSet.getString("id");
} else {
System.out.println("出版社不存在");
return;
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
RowMapper rowMapper = new RowMapper();
DBUtil.query(sql, rowMapper, publisherName);
if (rowMapper.publisher_id != null) {
sql = "insert book (id,isbn,name,publisher_id) values (?,?,?,?)";
DBUtil.update(sql, id, isbn, name, rowMapper.publisher_id);
System.out.println("添加成功");
}
}
}
10、Client
简单的管理界面
/**
* 书籍管理系统
*
* @author Administrator
*/
public class Client {
public static void main(String[] args) {
while (true) {
menu();
}
}
/**
* 主菜单
*
* @author Administrator
*/
private static void menu() {
System.out.println("1、出版社管理：");
System.out.println("2、书籍管理：");
System.out.println("3、退出");
Scanner scanner = new Scanner(System.in);
String choose = scanner.nextLine();
switch (choose) {
case "1": {
new PublisherManager().publisherManagerMenu();
break;
}
case "2": {
new BookManager().bookManagerMenu();
break;
}
case "3": {
System.exit(0);
break;
}
default:
System.out.println("请输入1-3的数字");
}
}
}