java计算年龄

Question

Java根据生日计算年龄，要保留两位小数，各位大侠帮帮忙啊
换个说法就是两个日期相减（日期形式：YYYY—MM—DD）得到的年数要精确到2位小数

Answer 1

import java.util.Calendar;
import java.util.Date;
import java.awt.*;
import java.awt.event.*;
import java.text.NumberFormat;

public class H {
public static void main(String args[]) {
new Time("年龄计算器");

}
}

class Time extends Frame implements ActionListener {
Calendar calendar;
Button button;
TextField t1, t2, t3;
Label l, l1, l2, l3;

Time(String s) {
super(s);
setLayout(new FlowLayout());
button = new Button("确定");
button.addActionListener(this);
t1 = new TextField(2);
t2 = new TextField(2);
t3 = new TextField(2);
l = new Label(" 请输入您的生日 ");
l.setBackground(Color.cyan);
l1 = new Label("年");
l2 = new Label("月");
l3 = new Label("日");
add(l);
add(t1);
add(l1);
add(t2);
add(l2);
add(t3);
add(l3);
add(button);
setBounds(100, 100, 280, 100);
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
setVisible(true);
validate();
}

public void actionPerformed(ActionEvent e) {
calendar = Calendar.getInstance();
calendar.setTime(new Date());
NumberFormat f = NumberFormat.getInstance();
long time = calendar.getTimeInMillis();
if (e.getSource() == button) {
try {
int n = Integer.parseInt(t1.getText());
int y = Integer.parseInt(t2.getText());
int r = Integer.parseInt(t3.getText());
calendar.set(n, y - 1, r);
double time1 = calendar.getTimeInMillis();
double c = (time - time1) / (1000 * 60 * 60 * 24);
double d = c/365;
f.setMaximumFractionDigits(2);
String s = f.format(d);
l.setText("您的年龄约为" + s + " 岁");
} catch (NumberFormatException ee) {
l.setText("请正确输入");
}
}
}
}

功底浅薄，如果有问题，还望指教。

Answer 2

private static String dealAge(int days, Date bornDate){
String age = "";
if(days < 0 || bornDate == null){
return "-";
}
Date currentDate = DateTool.getNextDate(bornDate, days); //当前日期

Calendar from = Calendar.getInstance();
from.setTime(bornDate);
Calendar to = Calendar.getInstance();
to.setTime(currentDate);

int fromYear = from.get(Calendar.YEAR);
int fromMonth = from.get(Calendar.MONTH);
int fromDay = from.get(Calendar.DAY_OF_MONTH);
int toYear = to.get(Calendar.YEAR);
int toMonth = to.get(Calendar.MONTH);
int toDay = to.get(Calendar.DAY_OF_MONTH);
int year = toYear - fromYear;
int month = toMonth - fromMonth;
int day = toDay - fromDay;

if(month < 0){
year += -1;
month += 12;
}
if(day < 0 ){
month += -1;
Calendar lastMonth = Calendar.getInstance();
lastMonth.setTime(DateTool.getNextMonth(currentDate, -1));
day += lastMonth.getActualMaximum(Calendar.DAY_OF_MONTH);
}

// System.out.println("bornDate="+DateTool.getFullDate().format(bornDate));
// System.out.println("currentDate="+DateTool.getFullDate().format(currentDate));
// System.out.println("oneYear="+DateTool.getFullDate().format(oneYear));
// System.out.println("year="+year);
// System.out.println("month="+month);
// System.out.println("day="+day);
if(year < 1){ //小于1岁
if(month > 0){
age += month + "个月";
}
if(day >= 0){
if(StringUtils.isNotBlank(age)){
age += "零" + day + "天";
}else{
age += day + "天";
}
}
}else{
age += year + "岁";
if(month > 0){
age += month + "个月";
}else{
if(day > 0){
age += "零" + day + "天";
}
}
}
return age;
}

Answer 3

String birthDay = "1990-01-01";
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
//得到当前的年份
String cYear = sdf.format(new Date()).substring(0,4);
//得到生日年份
String birthYear = birthDay .substring(0,4);

int age = Integer.parseInt(cYear) - Integer.parseInt(birthYear);

//不会产生小数啊。

Answer 4

如果不是要求特别精确地话：求出两日期相差天数,将日期格式化(YYYYMMDD),再将格式化 后的日期转化为数值再除以365就ok了

Answer 5

SimpleDateFormat myFormatter = new SimpleDateFormat("yyyy-MM-dd");
java.util.Date date=new Date();
java.util.Date mydate= myFormatter.parse("2003-05-01");
long day=(date.getTime()-mydate.getTime())/(24*60*60*1000) + 1;
String year=new java.text.DecimalFormat("#.00").format(day/365f);
System.out.println("niu:" + year);本回答被提问者和网友采纳