將JavaScript函數轉換爲Java

Question

我想將此代碼從JavaScript更改爲Java servlet。任何人都可以指導我找到解決方案嗎？

var dob1 = document.getElementById(id).value; 
var today = new Date(), 
dob = new Date(dob1), 
age = new Date(today - dob).getFullYear() - 1970; 

Answer 1

使用Calendar API。

String dobString = "1978-03-26"; 
Date dobDate = new SimpleDateFormat("yyyy-MM-dd").parse(dobString); 

Calendar dobCalendar = Calendar.getInstance(); 
dobCalendar.setTime(dobDate); 
Calendar today = Calendar.getInstance(); 
int age = -1; 

while (today.after(dobCalendar)) { 
    age++; 
    today.add(Calendar.YEAR, -1); 
} 

System.out.println(age); // 32 

由於Calendar API是太可怕了，我建議JodaTime代替。

String dobString = "1978-03-26"; 
DateTime dobDate = DateTimeFormat.forPattern("yyyy-MM-dd").parseDateTime(dobString); 
DateTime today = new DateTime(); 
int age = Years.yearsBetween(dobDate, today).getYears(); 
System.out.println(age); // 32