多态的设计应用及实现之汽车租价计算

目标: 多态的设计应用及实现.

汽车出租商准备根据汽车购买的价格及汽车种类来制定
各种汽车的每日租金.
具体规则如下:

家用轿车: 购买价格 * (1/1000) + 10
旅行车: 购买价格 * (2/1000)
越野车: 购买价格 * (3/1000)
大客车: 购买价格 * (3/1000) + 400

计算并生成价格清单, 并在大客车前面加上'*'来标识. 输出结果按购买日期降序排列.
源文件及输出文件的价格单位都精确到元. 计算中出现不足1元的部分以1元来计算.
汽车分类及计算方法可能会根据今后业务发展情况调整, 因此请尽量保持代码易于修改和维护.

源文件格式:（源文件请自行编制，文件名请用src.txt）
车辆名称 购买价格 购买日期 车辆类型
金杯 100000 2007-08-02 旅行车
宝马X5 1000000 2007-01-29 越野车
别克 80201 2008-02-06 家用轿车
黄海 1200000 2009-01-03 大客车

输出格式: [标记] [购买价格] [购买日期] [车辆类型] [计算后价格]（输出文件文件名请用dst.txt）
* 黄海 1200000 2009-01-03 大客车 4000

package com.neusoft; import java.util.*; import java.io.*; import java.math.BigDecimal; import java.text.*; /** * 主函数类 * @author * */ public class MainRent { public static List<Car> readFile() throws IOException{ List<Car> carList = new ArrayList<Car>(); String s = ""; BufferedReader br=null; try{ br = new BufferedReader(new FileReader("c:\\src.txt")); try{ while(((s=br.readLine())!=null)){ Car car; String[] buf = s.split(" "); if(buf[3].equals("大客车")) car= new BigBus(); else if(buf[3].equals("旅行车")) car = new TravelCar(); else if(buf[3].equals("越野车")) car= new YueyeCar(); else car = new HomeCar(); car.setCarName(buf[0]); car.setPrice(new BigDecimal(buf[1])); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); Date date = sdf.parse(buf[2]); car.setDate(date); car.setCarClass(buf[3]); carList.add(car); } }catch(Exception e){ e.printStackTrace(); } }catch(FileNotFoundException e){ e.printStackTrace(); }finally{ if(br!=null){ br.close(); System.out.println("文件关闭"); } } return carList; } public static void writeFile(List<Car> carList){ BufferedWriter bw=null; try{ bw= new BufferedWriter(new FileWriter("c:/dst.txt")); for(Iterator<Car> it = carList.iterator();it.hasNext();){ bw.write(it.next().toString()); bw.newLine(); } bw.close(); }catch(Exception e){ e.printStackTrace(); }finally{ try { bw.close(); System.out.println("再次关闭文件"); } catch (IOException e) { e.printStackTrace(); } } } public static void main(String[] args) throws IOException{ List<Car>carList = readFile(); Collections.sort(carList, new Comparator<Object>(){ public int compare(Object o1,Object o2){ Car car1 = (Car)o1; Car car2 = (Car)o2; return car2.getDate().compareTo(car1.getDate()); } }); writeFile(carList); } } package com.neusoft; import java.math.BigDecimal; import java.text.SimpleDateFormat; import java.util.Date; /** * 洗车的基础类 * * @author * */ public class Car { protected String carName;// 车辆名称 protected BigDecimal price;// 购买价格 protected Date date;// 购买日期 protected String carClass;// 车辆类别 /** * 计算租金 * * @return BigDecimal */ public BigDecimal countRent1() { return new BigDecimal("0"); } /** * @return the carClass */ public String getCarClass() { return carClass; } /** * @return the carName */ public String getCarName() { return carName; } /** * @return the date */ public Date getDate() { return date; } /** * @return the price */ public BigDecimal getPrice() { return price; } /** * @param carClass * the carClass to set */ public void setCarClass(String carClass) { this.carClass = carClass; } /** * @param carName * the carName to set */ public void setCarName(String carName) { this.carName = carName; } /** * @param date * the date to set */ public void setDate(Date date) { this.date = date; } /** * @param price * the price to set */ public void setPrice(BigDecimal price) { this.price = price; } public String toString() { String ret = ""; if (carClass.equals("大客车")) ret += "*"; else ret += " "; ret += carName + " " + price + " " + new SimpleDateFormat("yyyy-MM-dd").format(date) + " " + carClass + " " + countRent1(); return ret; } } package com.neusoft; import java.math.BigDecimal; /** * 大客车类，继承基础车类 * * @author * */ public class BigBus extends Car { @Override public BigDecimal countRent1() { BigDecimal ret = null; ret = price .multiply(new BigDecimal("3").divide(new BigDecimal("1000"))) .add(new BigDecimal("400")); ret = ret.setScale(0, BigDecimal.ROUND_CEILING); return ret; } } package com.neusoft; import java.math.BigDecimal; /** * 家用轿车类，继承基础车类 * * @author * */ public class HomeCar extends Car { @Override public BigDecimal countRent1() { BigDecimal ret = null; ret = price .multiply(new BigDecimal("1").divide(new BigDecimal("1000"))) .add(new BigDecimal("10")); ret = ret.setScale(0, BigDecimal.ROUND_CEILING); return ret; } } package com.neusoft; import java.math.BigDecimal; /** * 旅行车类，继承基础车类 * * @author * */ public class TravelCar extends Car { @Override public BigDecimal countRent1() { BigDecimal ret = null; ret = price .multiply(new BigDecimal("2").divide(new BigDecimal("1000"))); ret = ret.setScale(0, BigDecimal.ROUND_CEILING); return ret; } } package com.neusoft; import java.math.BigDecimal; /** * 越野车类，继承基础车类 * * @author * */ public class YueyeCar extends Car { @Override public BigDecimal countRent1() { BigDecimal ret = null; ret = price .multiply(new BigDecimal("3").divide(new BigDecimal("1000"))); ret = ret.setScale(0, BigDecimal.ROUND_CEILING); return ret; } }