书店交易信息简单管理模型

Books类：对应数据库中的books表格

public class Books {
private String bookid;
private String bookname;
private  float bookprice;//单价
public String getBookid() {
return bookid;
}
public void setBookid(String bookid) {
this.bookid = bookid;
}
public String getBookname() {
return bookname;
}
public void setBookname(String bookname) {
this.bookname = bookname;
}
public float getBookprice() {
return bookprice;
}
public void setBookprice(float bookprice) {
this.bookprice = bookprice;
}

}

Customer类：对应数据库中的customer类

public class Customer {

private String customerid;
private String customername;
private float money_amount;//余额

public String getCustomerid() {
return customerid;
}
public void setCustomerid(String customerid) {
this.customerid = customerid;
}
public String getCustomername() {
return customername;
}
public void setCustomername(String customername) {
this.customername = customername;
}
public float getMoney_amount() {
return money_amount;
}
public void setMoney_amount(float money_amount) {
this.money_amount = money_amount;
}

}

Inventory类：对应数据库中的库存表

public class Inventory {

private String bookid;
private int book_amount;//剩余书本数量
public String getBookid() {
return bookid;
}
public void setBookid(String bookid) {
this.bookid = bookid;
}
public int getBook_amount() {
return book_amount;
}
public void setBook_amount(int book_amount) {
this.book_amount = book_amount;
}

}

Deating类：对应数据库中的交易表
import java.util.Date;
/**
* 交易表类
* @author dingshuangen
*
*/
public class Dealing {

private String bookid;
private String customerid;
private int sal_amount;
private float money;
public float getMoney() {
return money;
}
public void setMoney(float money) {
this.money = money;
}
private Date sal_date;//交易时间

public String getBookid() {
return bookid;
}
public void setBookid(String bookid) {
this.bookid = bookid;
}
public String getCustomerid() {
return customerid;
}
public void setCustomerid(String customerid) {
this.customerid = customerid;
}
public float getSal_amount() {
return sal_amount;
}
public void setSal_amount(int sal_amount) {
this.sal_amount = sal_amount;
}
public Date getSal_date() {
return sal_date;
}
public void setSal_date(Date sal_date) {
this.sal_date = sal_date;
}
@Override
public String toString() {
return "Dealing [bookid=" + bookid + ", customerid=" + customerid + ", 购买数量=" + sal_amount + ", 销售金额="
+ money + ", 交易日期=" + sal_date + "]";
}

}


BookDao类：对数据库中所有表格进行操作的方法类

import java.sql.Connection;
import java.sql.Date;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class BookDao {
/**
* 查询所有书本的剩余信息
* @return
*/
public List<String> selectAll() {
ArrayList<String> list=new ArrayList<String>();
String sql="select * from books b join inventory i on b.bookid=i.bookid";
Connection conn=JdbcUtil.getConnection();
PreparedStatement ps=null;
ResultSet rs=null;
try {
ps=conn.prepareStatement(sql);
rs=ps.executeQuery();
while(rs.next()) {
list.add(rs.getString("bookid")+"\t"+rs.getString("bookname")+"\t剩余："+rs.getInt("book_amount"));
}
return list;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
/**
* 查询具体某一本书的剩余信息
* @param b
* @return
*/
public List<String> select(Books b) {

ArrayList<String> list=new ArrayList<String>();
String sql="select * from books b join inventory i on b.bookid=i.bookid and b.bookid=?";
Connection conn=JdbcUtil.getConnection();
PreparedStatement ps=null;
ResultSet rs=null;
try {
ps=conn.prepareStatement(sql);
ps.setString(1, b.getBookid());
rs=ps.executeQuery();
while(rs.next()) {
list.add(rs.getString("bookid")+"\t"+rs.getString("bookname")+"\t剩余："+rs.getInt("book_amount"));
}
return list;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

return null;
}
/**
* 销售书籍
* @param c买书的客户
* @param b购买的书
* @param 购买数量
*/
public void salBook(Customer c,Books b,Inventory i,int num) {
Connection conn=JdbcUtil.getConnection();

PreparedStatement ps1=null;
PreparedStatement ps2=null;
PreparedStatement ps3=null;
try {

conn.setAutoCommit(false);//设置为不自动提交事务

//客户余额不足时抛出异常提示余额不足
if(c.getMoney_amount()<b.getBookprice()*num) {
System.out.println("交易失败");
throw new Exception("余额不足");
}
//对客户信息进行修改的sql语句
String sql1="update customer set money_amount=? where customerid=?";
ps1=conn.prepareStatement(sql1);
//更新用户个人信息
c.setMoney_amount(c.getMoney_amount()-num*b.getBookprice());
ps1.setFloat(1, c.getMoney_amount());
ps1.setString(2, c.getCustomerid());
ps1.execute();

//对书籍库存是否满足条件进行判断
if(i.getBook_amount()<num) {
System.out.println("交易失败");
throw new Exception("书籍库存不足");
}
//对库存信息进行修改的sql语句
String sql2="update inventory set book_amount= ? where bookid=?";
//更新库存信息
ps2=conn.prepareStatement(sql2);
i.setBook_amount(i.getBook_amount()-num);
ps2.setInt(1,i.getBook_amount());
ps2.setString(2, b.getBookid());
ps2.execute();

//对交易信息进行记录的sql语句
String sql3="insert into dealing values(?,?,?,?,?)";
//记录交易信息
ps3=conn.prepareStatement(sql3);
ps3.setString(1, b.getBookid());
ps3.setString(2, c.getCustomerid());
ps3.setInt(3, num);
ps3.setFloat(4, num*b.getBookprice());
ps3.setDate(5, new Date(System.currentTimeMillis()));
ps3.execute();
//提交所有数据信息
conn.commit();
System.out.println("交易成功");
}catch(Exception e) {
e.printStackTrace();
}finally {
//关闭所有资源
try {
ps1.close();
ps2.close();
ps3.close();
} catch (SQLException e) {
System.err.println("资源关闭异常");
}
}
}
/**
* 查询交易信息
* @return返回值为一个Dealing类型的List集合
*/
public List<Dealing> selectDealing(){

String sql="select * from dealing";

ArrayList<Dealing> list=new ArrayList<Dealing>();
Connection conn=JdbcUtil.getConnection();
PreparedStatement ps=null;
ResultSet rs=null;
try {
ps=conn.prepareStatement(sql);
rs=ps.executeQuery();
while(rs.next()) {
Dealing d=new Dealing();
d.setBookid(rs.getString("bookid"));
d.setCustomerid(rs.getString("customerid"));
d.setSal_amount(rs.getInt("sal_amount"));
d.setMoney(rs.getFloat("money"));
d.setSal_date(rs.getDate("sal_date"));
list.add(d);
}
return list;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
/**
* 根据书本id获得书的信息
* @param bookid
* @return
*/
public Books getBooks(String bookid) {

String sql="select * from books where bookid=?";
Connection conn=JdbcUtil.getConnection();
PreparedStatement ps=null;
ResultSet rs=null;
Books b=new Books();
try {
ps=conn.prepareStatement(sql);
ps.setString(1, bookid);
rs=ps.executeQuery();
while(rs.next()) {
b.setBookid(rs.getString("bookid"));
b.setBookname(rs.getString("bookname"));
b.setBookprice(rs.getFloat("bookprice"));
}
return b;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

return null;
}

/**
* 根据顾客id获得顾客的信息
* @param customerid
* @return
*/
public Customer getCustomer(String customerid) {

String sql="select * from customer where customerid=?";
Connection conn=JdbcUtil.getConnection();
PreparedStatement ps=null;
ResultSet rs=null;
Customer c=new Customer();
try {
ps=conn.prepareStatement(sql);
ps.setString(1, customerid);
rs=ps.executeQuery();
while(rs.next()) {
c.setCustomerid(rs.getString(1));
c.setCustomername(rs.getString(2));
c.setMoney_amount(rs.getFloat(3));
}
return c;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

return null;
}

/**
* 获得当前booksid的库存信息
* @param bookid
* @return
*/
public Inventory getInventory(String bookid) {

String sql="select * from inventory where bookid=?";
Connection conn=JdbcUtil.getConnection();
PreparedStatement ps=null;
ResultSet rs=null;
Inventory in=new Inventory();
try {
ps=conn.prepareStatement(sql);
ps.setString(1, bookid);
rs=ps.executeQuery();
while(rs.next()) {
in.setBookid(rs.getString(1));
in.setBook_amount(rs.getInt(2));
}
return in;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

return null;
}

}


JdbcUtil类：包括了获得连接的静态方法以及测试方法 

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.List;

public class JdbcUtil {

private static final String URL="jdbc:mysql://localhost:3306/jdbc";
private static final String USER="root";
private static final String PASSWORD="0325";
private static Connection conn=null;
//静态块，只加载一次
static {

try {
//加载驱动
Class.forName("com.mysql.jdbc.Driver");
//获得连接
conn=DriverManager.getConnection(URL, USER, PASSWORD);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}

}
//获得连接的方法
public static Connection getConnection() {
return conn;
}
//测试方法
public static void main(String[] args) {

BookDao bd=new BookDao();
//获得id为B02的书籍信息
Books b=bd.getBooks("B01");
//获得id为B02的书籍库存信息
Inventory in=bd.getInventory("B01");
//获得客户C02的信息
Customer c=bd.getCustomer("C01");
//查询编号为书籍b的库存信息
List<String> list1=bd.select(b);
//输出信息
System.out.println("========当前查询书籍库存信息为：========");
for (String string : list1) {
System.out.println(string);
}
//查询出库存剩余的书本信息
System.out.println("========当前所有书籍库存信息为：========");
List<String> list=bd.selectAll();
//输出信息
for (String string : list) {
System.out.println(string);
}
//查询客户余额
System.out.println("###你的余额为："+c.getMoney_amount());
//顾客C02买了5本编号为B01的书
System.out.println("========交易状态：========");
bd.salBook(c, b, in, 3);
//查询交易信息
System.out.println("\n\n========所有的交易信息为：========");
List<Dealing> l=bd.selectDealing();
for (Dealing de : l) {
System.out.println(de.toString());
}
//查询交易后的库存信息
System.out.println("\n\n========交易后所有书籍库存信息为：========");
List<String> list2=bd.selectAll();
for (String string : list2) {
System.out.println(string);
}
System.out.println("###交易成功后你的余额为："+c.getMoney_amount());
//所有操作执行完成后关闭连接
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

}