Java从零编写汽车租赁系统全程分析
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掌握数据库、JDBC、三层架构等相关知识。
掌握Druid连接池、Apache的DBUtils使用 。
项目需求
某汽车租赁公司出租多种轿车和客车,出租费用以日为单位计算。
出租车型及信息如下表所示:
车型 | 具体信息 | 日租金 | 折扣 |
轿车 | 宝马X6(京NY28588) | 800 | days>7天9折 days>30天8折 days>150天7折 |
宝马550i(京CNY3284) | 600 | ||
别克林荫大道(京NT37465) | 300 | ||
别克GL8(京NT96968) | 600 | ||
客车 | 金杯,16座(京6566754) | 800 | days>=3天9折 days>=7天8折 days>=30天7折 days>=150天6折 |
金龙,16座(京8696997) | |||
金杯,34座(京9696996) | 1500 | ||
金龙,34座(京8696998) |
设计步骤
开发思路
(1)明确需求
(2)编码顺序
1)、添加需要的jar包到项目中,将lib文件夹中的jar文件通过鼠标右单击选择Build Path的方式添加到你设置的eatJar文件目录里。
2)、创建database.properties文件,用来配置注册驱动和数据库连接对象的相关数据。
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/java221804
username=root
password=huanghuang
initialSize=10
maxActive=30
maxIdle=5
maxWait=3000
3)、添加需要的工具类DBUtils类
package cn.eat.utils; import java.io.IOException; import java.io.InputStream; import java.util.Properties; import javax.sql.DataSource; import com.alibaba.druid.pool.DruidDataSource; import com.alibaba.druid.pool.DruidDataSourceFactory; public class DBUtils { private static DruidDataSource druidDataSource; static { Properties properties = new Properties(); try { InputStream is = DBUtils.class .getResourceAsStream("/database.properties"); properties.load(is); druidDataSource = (DruidDataSource) DruidDataSourceFactory .createDataSource(properties); } catch (IOException e) { e.printStackTrace(); } catch (Exception e) { e.printStackTrace(); } } public static DataSource getDataSource(){ return druidDataSource; } }
4)、创建数据表:automobile表
CREATE TABLE `automobile` ( `numberPlate` varchar(20) DEFAULT NULL, `brand` varchar(10) DEFAULT NULL, `dayRent` double DEFAULT NULL, `type` varchar(10) DEFAULT NULL, `seat` int(11) DEFAULT NULL )
automobile表效果展示
5)、完成父类(汽车类)的编写
6)、再完成子类(客车类和轿车类)的编写
7)、数据访问层DAO层的接口和实现类的增删改查方法的编写
8)、服务层Service层的接口和实现类的增删改查方法的编写
9)、最后完成视图层View层测试类的编写
类的属性和方法
属性:
- 汽车类:车牌号、品牌、日租金
- 客车类:车牌号、品牌、日租金、座位数
- 轿车类:车牌号、品牌、日租金、型号
- 汽车业务类:忽略
- 汽车租赁管理类:忽略
方法:
定义租车的方法,不同类型的汽车采用不同租金方法进行计算。
代码展示
1、汽车类(父类)
package cn.automobile.entity; public abstract class Automobile { // 定义汽车类的属性(车牌号、品牌、日租金) private String numberPlate; private String brand; private double dayRent; public Automobile() { super(); } public Automobile(String numberPlate, String brand, double dayRent) { super(); this.numberPlate = numberPlate; this.brand = brand; this.dayRent = dayRent; } public String getNumberPlate() { return numberPlate; } public void setNumberPlate(String numberPlate) { this.numberPlate = numberPlate; } public String getBrand() { return brand; } public void setBrand(String brand) { this.brand = brand; } public double getDayRent() { return dayRent; } public void setDayRent(double dayRent) { this.dayRent = dayRent; } //定义计算租金的抽象方法 public abstract double calRent(int days,double dayRent); @Override public String toString() { return "Automobile [numberPlate=" + numberPlate + ", brand=" + brand + ", dayRent=" + dayRent + "]"; } }
2、轿车类(子类)
package cn.automobile.entity; public class Bus extends Automobile { private int seat; public Bus() { super(); } public Bus(String numberPlate, String brand, double dayRent, int seat) { super(numberPlate, brand, dayRent); this.seat = seat; } public int getSeat() { return seat; } public void setSeat(int seat) { this.seat = seat; } @Override public double calRent(int days,double dayRent) { // System.out.println("bus"); double discount=dayRent*days; if(days>150){ discount*=0.6; }else if(days>30){ discount*=0.7; }else if(days>7){ discount*=0.8; }else if(days>3){ discount*=0.9; } return discount; } }
3、客车类(子类)
package cn.automobile.entity; public class Car extends Automobile { // 定义特有属性 private String type; public Car() { super(); } public Car(String numberPlate, String brand, double dayRent, String type) { super(numberPlate, brand, dayRent); this.type = type; } public String getType() { return type; } public void setType(String type) { this.type = type; } @Override public double calRent(int days,double dayRent) { // System.out.println("car"); double discount=dayRent*days; if(days>150){ discount*=0.7; }else if(days>30){ discount*=0.8; }else if(days>7){ discount*=0.9; } return discount; } }
4、数据访问层AutomobileDao接口
package cn.automobile.dao; import cn.automobile.entity.Automobile; import cn.automobile.entity.Bus; import cn.automobile.entity.Car; public interface AutomobileDao { //查bus Automobile selectOne(Bus bus); //查car Automobile selectOne(Car car); }
5、数据访问层AutomobileDaoImpl实现类
package cn.automobile.dao.Impl; import java.sql.SQLException; import java.util.List; import org.apache.commons.dbutils.QueryRunner; import org.apache.commons.dbutils.handlers.BeanHandler; import org.apache.commons.dbutils.handlers.BeanListHandler; import cn.automobile.dao.AutomobileDao; import cn.automobile.entity.Automobile; import cn.automobile.entity.Bus; import cn.automobile.entity.Car; import cn.automobile.utils.DBUtils; public class AutomobileDaoImpl implements AutomobileDao { private QueryRunner queryRunner = new QueryRunner(DBUtils.getDataSource()); @Override public Automobile selectOne(Bus bus) { String sql="select * from automobile;"; try { List<Bus> listAutomobiles=queryRunner.query(sql, new BeanListHandler<Bus>(Bus.class)); for (Bus bus1 : listAutomobiles) { if(bus1.getBrand().equals(bus.getBrand())&&bus1.getSeat()==bus.getSeat()){ return bus1; } } } catch (SQLException e) { e.printStackTrace(); } return null; } @Override public Automobile selectOne(Car car) { String sql="select * from automobile;"; try { List<Car> listAutomobiles=queryRunner.query(sql, new BeanListHandler<Car>(Car.class)); for (Car car1 : listAutomobiles) { if(car1.getBrand().equals(car.getBrand())&&car1.getType().equals(car.getType())){ return car1; } } } catch (SQLException e) { e.printStackTrace(); } return null; } }
6、服务层 AutomobileService 接口
package cn.automobile.service; import cn.automobile.entity.Automobile; import cn.automobile.entity.Bus; import cn.automobile.entity.Car; public interface AutomobileService { //查bus Automobile selectBus(Bus bus); //查car Automobile selectCar(Car car); }
7、服务层AutomobileServiceImpl 实现类
package cn.automobile.service.impl; import cn.automobile.dao.AutomobileDao; import cn.automobile.dao.Impl.AutomobileDaoImpl; import cn.automobile.entity.Automobile; import cn.automobile.entity.Bus; import cn.automobile.entity.Car; import cn.automobile.service.AutomobileService; public class AutomobileServiceImpl implements AutomobileService { AutomobileDao autoD=new AutomobileDaoImpl(); @Override public Automobile selectBus(Bus bus) { return autoD.selectOne(bus); } @Override public Automobile selectCar(Car car) { return autoD.selectOne(car); } }
8、视图层:租车测试AutomobileMgr类
package cn.automobile.view; import java.util.Scanner; import cn.automobile.entity.Automobile; import cn.automobile.entity.Bus; import cn.automobile.entity.Car; import cn.automobile.service.AutomobileService; import cn.automobile.service.impl.AutomobileServiceImpl; public class AutomobileMgr { public static void main(String[] args) { Scanner sc=new Scanner(System.in); String brand=null,type=null; int seat=0; double money = 0; Automobile automobile=null; AutomobileService autoS=new AutomobileServiceImpl(); System.out.println("********欢迎光临租赁公司********\n"); System.out.println("请选择汽车类型:1、轿车\t2、客车"); int autoType=sc.nextInt(); if(autoType==1){ System.out.println("请选择轿车品牌:1、宝马\t2、别克"); brand=(sc.nextInt()==1)?"宝马":"别克"; if(brand=="宝马"){ System.out.println("请选择轿车型号:1、X6\t2、550i"); type=(sc.nextInt()==1)?"X6":"550i"; }else if(brand=="别克"){ System.out.println("请选择轿车型号:1、林荫大道\t2、GL8"); type=(sc.nextInt()==1)?"林荫大道":"GL8"; } }else if(autoType==2){ System.out.println("请选择客车品牌:1、金杯\t2、金龙"); brand=(sc.nextInt()==1)?"金杯":"金龙"; System.out.println("请选择需要的座位数:1、16座\t2、34座"); seat=(sc.nextInt()==1)?16:34; } System.out.println("请选择租赁天数:"); int days=sc.nextInt(); if (seat==0) { Car car=new Car(); car.setBrand(brand); car.setType(type); automobile=autoS.selectCar(car); money=car.calRent(days,automobile.getDayRent()); }else if(seat!=0) { Bus bus=new Bus(); bus.setBrand(brand); bus.setSeat(seat); automobile=autoS.selectBus(bus); money=bus.calRent(days,automobile.getDayRent()); } // System.out.println(automobile); System.out.println("租车成功!请按照"+automobile.getNumberPlate()+"车牌号取车!租金为:"+money+"元"); } }
效果展示
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