运动状态最佳心率计算器 (Target-Heart-Rate Calculator)

基本业务逻辑：

运动时最高心率：220-年龄（年）

运动时目标心率范围：运动时最高心率×0.5~运动时最高心率×0.85

说明：计算公式出处为American Heart Association (AHA) (www.americanheart.org/presenter.jhtml?identifier=4736)

代码如下：

//Exercise 3.16: Target-Heart-Rate Calculator,HeartRates.java
//By Pandenghuang@163.com
import javax.swing.JOptionPane;; // program uses class Scanner

public class HeartRateCalculator
{
private String name;
private int year;

public HeartRateCalculator(String name,int year)
{
this.name = name;

if (year > 1916 && year<2016)
this.year = year;
else
this.year = 1980;
}

public int getage()
{
return 2016-year;
}

public int getMaxHeartRate()
{
return 220-getage();
}

public String getTargetHeartRate()
{
return String.format("%d 到 %d", (int)(getMaxHeartRate()*0.5),(int)(getMaxHeartRate()*0.85));
}

public static void main(String[] args)
{

String name=JOptionPane.showInputDialog("请输入您的名字：");
int year=Integer.parseInt(JOptionPane.showInputDialog("请输入您的出生年份："));

HeartRates heartRates=new HeartRates(name,year,10,20);

int age=heartRates.getage();
System.out.println(age);
int maxHeartRate=heartRates.getMaxHeartRate();
System.out.println(maxHeartRate);
String targetHeartRate=heartRates.getTargetHeartRate();
System.out.println(targetHeartRate);

String message=String.format("%s，你好！\n您的年龄为：%d岁\n您锻炼时最高心率不能超过%d次/秒\n您锻炼时的理想心率（次/秒）为：%s",name,age,maxHeartRate,targetHeartRate);
JOptionPane.showMessageDialog(null, message);

}
}

运行截屏如下：