如何在java中计算两个日期之间的年龄或差异

how to calculate age or difference between two dates in java

提问by XylemRaj

I want to get the number of months between 2 dates.The dates are someones birthday and the current date.So i m getting the number of years in between the two dates but not the number of months..

我想得到两个日期之间的月数。日期是某人的生日和当前日期。所以我得到了两个日期之间的年数，而不是月数。

Suppose my dates are 06/09/2011and 06/11/2012.So i want the answer to be 1yr 2mths .I am getting the year but not the month.Please help.Below is the code for getting the number of years

假设我的日期是06/09/2011和06/11/2012。所以我希望答案是 1yr 2mths 。我得到的是年份而不是月份。请帮忙。下面是获取年数的代码

 public int getAge(Date dateOfBirth)      {                                                                                                                                                                         

    today = Calendar.getInstance(); 
    Calendar birthDate = Calendar.getInstance();

    birthDate.setTime(dateOfBirth);
    if (birthDate.after(today)) {
        throw new IllegalArgumentException("Can't be born in the future");
    }

    age = today.get(Calendar.YEAR) - birthDate.get(Calendar.YEAR);
    month = today.get(Calendar.MONTH) - birthDate.get(Calendar.MONTH);

    if ( (birthDate.get(Calendar.DAY_OF_YEAR) - today.get(Calendar.DAY_OF_YEAR) > 3) ||
            (birthDate.get(Calendar.MONTH) > today.get(Calendar.MONTH ))){
        days = birthDate.get(Calendar.DAY_OF_MONTH) - today.get(Calendar.DAY_OF_MONTH);
        age--;

        Toast.makeText(getApplicationContext(), "inside if", Toast.LENGTH_SHORT).show();
        Log.e("month is",month+"");
        Log.e("Days",days+ " left");


    }else if ((birthDate.get(Calendar.MONTH) == today.get(Calendar.MONTH )) &&
              (birthDate.get(Calendar.DAY_OF_MONTH) > today.get(Calendar.DAY_OF_MONTH ))){
        Toast.makeText(getApplicationContext(), "inside else if", Toast.LENGTH_SHORT).show();

        age--;
    }

    return age;

采纳答案by Mehul Joisar

I have recently created a demo and uploaded here.

我最近创建了一个演示并上传到这里。

It is using JodaTimelibrary for efficient results.

它正在使用JodaTime库来获得有效的结果。

I hope it will be useful.

我希望它会很有用。

Screenshot:

截屏：

Code:

代码：

MainActivity.java

主活动.java

public class MainActivity extends Activity {

    private SimpleDateFormat mSimpleDateFormat;
    private PeriodFormatter mPeriodFormat;

    private Date startDate;
    private Date endDate;
    private Date birthDate;


    private TextView tvStartDate,tvEndDate,tvDifferenceStandard,tvDifferenceCustom,tvBirthDate,tvAgeStandard,tvAgeCustom;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        init();

        //determine dateDiff
        Period dateDiff = calcDiff(startDate,endDate);
        tvDifferenceStandard.setText(PeriodFormat.wordBased().print(dateDiff));
        tvDifferenceCustom.setText( mPeriodFormat.print(dateDiff));


        //determine age
        Period age = calcDiff(birthDate,new Date());
        tvAgeStandard.setText(PeriodFormat.wordBased().print(age));
        tvAgeCustom.setText( mPeriodFormat.print(age));

    }

    private void init() {

        //ui
        tvStartDate = (TextView)findViewById(R.id.tvStartDate);
        tvEndDate = (TextView)findViewById(R.id.tvEndDate);
        tvDifferenceStandard = (TextView)findViewById(R.id.tvDifferenceStandard);
        tvDifferenceCustom = (TextView)findViewById(R.id.tvDifferenceCustom);
        tvBirthDate = (TextView)findViewById(R.id.tvBirthDate);
        tvAgeStandard = (TextView)findViewById(R.id.tvAgeStandard);
        tvAgeCustom = (TextView)findViewById(R.id.tvAgeCustom);



        //components
        mSimpleDateFormat = new SimpleDateFormat("dd/MM/yy");
        mPeriodFormat = new PeriodFormatterBuilder().appendYears().appendSuffix(" year(s) ").appendMonths().appendSuffix(" month(s) ").appendDays().appendSuffix(" day(s) ").printZeroNever().toFormatter();


        try {
            startDate = mSimpleDateFormat.parse(tvStartDate.getText().toString());
            endDate =  mSimpleDateFormat.parse(tvEndDate.getText().toString());
            birthDate = mSimpleDateFormat.parse(tvBirthDate.getText().toString());

        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    private Period calcDiff(Date startDate,Date endDate)
    {
        DateTime START_DT = (startDate==null)?null:new DateTime(startDate);
        DateTime END_DT = (endDate==null)?null:new DateTime(endDate);

        Period period = new Period(START_DT, END_DT);

        return period;

    }

}

activity_main.xml

活动_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >


<TextView 
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="Date Diff Calculator"
    android:textStyle="bold"
    android:gravity="center"
    android:background="@android:color/darker_gray"
    />


<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textStyle="bold"
    android:text="Start Date:" />

<TextView
    android:id="@+id/tvStartDate"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="06/09/2011" />

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textStyle="bold"
    android:text="End Date:" />

<TextView
    android:id="@+id/tvEndDate"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="29/10/2013" />

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textStyle="bold"
    android:text="Difference (Standard)" />

<TextView
    android:id="@+id/tvDifferenceStandard"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="result" />

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textStyle="bold"
    android:text="Difference (Custom)" />

<TextView
    android:id="@+id/tvDifferenceCustom"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="result" />


<TextView 
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="Age Calculator"
    android:textStyle="bold"
    android:gravity="center"
    android:background="@android:color/darker_gray"
    />

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textStyle="bold"
    android:text="Birth Date:" />

<TextView
    android:id="@+id/tvBirthDate"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="01/09/1989" />

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textStyle="bold"
    android:text="Age (Standard)" />

<TextView
    android:id="@+id/tvAgeStandard"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="result" />

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textStyle="bold"
    android:text="Age (Custom)" />

<TextView
    android:id="@+id/tvAgeCustom"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="result" />

Note:

笔记：

1) don't forget to add JodaTime libraryto your project

1）不要忘记add JodaTime library你的项目

2) As you can see in layout file, I have used fixed value for "Start Date","End Date" to calculate Date Differenceand fixed value for "Birth Date" to calculate Age. You may replace it with your dynamic values.

2) 正如您在布局文件中看到的，我使用了固定值 for"Start Date","End Date" to calculate Date Difference和固定值"Birth Date" to calculate Age. 你可以replace it with your dynamic values。

回答by GrIsHu

Joda Timehas code to do all this and more

Joda Time有代码可以完成所有这些以及更多

You can do the following to get the month between two dates:

您可以执行以下操作来获取两个日期之间的月份：

Calendar startCalendar = new GregorianCalendar();
startCalendar.setTime(startDate);
Calendar endCalendar = new GregorianCalendar();
endCalendar.setTime(endDate);

int diffYear = endCalendar.get(Calendar.YEAR) - startCalendar.get(Calendar.YEAR);
int diffMonth = diffYear * 12 + endCalendar.get(Calendar.MONTH) - startCalendar.get(Calendar.MONTH);

Check out Link

查看链接

Note:that if your dates are 2013-01-31and 2013-02-01, you get a distance of 1 month this way, which may or may not be what you want.

注意：如果您的日期是2013-01-31和2013-02-01，那么您将获得 1 个月的距离，这可能是您想要的，也可能不是。

回答by griFlo

java.time

时间

Because this answer got referenced from here…

因为这个答案是从这里引用的......

With java.timeclasses you can calculate the age very easy:

使用java.time类，您可以非常轻松地计算年龄：

long years = ChronoUnit.YEARS.between(LocalDate.of(1900, Month.NOVEMBER, 20), LocalDate.now());

or (if you need year and months)

或（如果您需要年份和月份）

Period p = Period.between(birthday, today);
p.getYears();
p.getMonths();

To count all the months in the entire period, as asked in the Question, call toTotalMonths.

要按问题中的要求计算整个期间的所有月份，请致电toTotalMonths。

int totalMonths = p.toTotalMonths();

回答by UJJVAL KUMAR

Age can be calculate in a very easy way. The following is my complete java code .

年龄可以很容易地计算出来。以下是我完整的java代码。

 public class age {


    public static void main(String [] args){
        Scanner s=new Scanner(System.in);
        Date dd=new Date();
        int d=Integer.parseInt(new SimpleDateFormat("dd").format(dd));
        int m=Integer.parseInt(new SimpleDateFormat("MM").format(dd));
        int y=Integer.parseInt(new SimpleDateFormat("yyyy").format(dd));
         System.out.println( "Enter Day ");
        int d1=Integer.parseInt(s.nextLine());
        System.out.println( "Enter Month ");
        int m1=Integer.parseInt(s.nextLine());
         System.out.println( "Year");
        int y1=Integer.parseInt(s.nextLine());
        if(d<d1){
            d+=30;
            m-=1;
        }
        if(m<m1){
            m+=12;
            y-=1;
        }
      System.out.println((y-y1)+" years "+(m-m1)+"  month "+(d-d1)+" days ");

    }
 }