如何从java中的当前日期计算下一个生日？ [英] How to calculate next birthday from current date in java?

问题描述

我正在从联系人和呼叫者应用程序中检索生日日期的不同格式。

I am retrieving different formats of birthday dates from contacts and callender application.

从这些日期中，我想计算从当前日期到下一个生日的剩余天数。

From these dates i want to calculate number of days left for next birthday from current date.

请帮助我该怎么做？

TextView left = (TextView) view.findViewById(R.id.dayslefy);
String birthday = cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Event.START_DATE));
left.setText(getDaysLeft(birthday)+ " days left");
public static int getDaysLeft(String dobString) {
    Calendar dob = getCalendarFromString(getNextBirthday(dobString));
    Calendar now = Calendar.getInstance();

    now.set(Calendar.HOUR, dob.get(Calendar.HOUR));
    now.set(Calendar.MINUTE, dob.get(Calendar.MINUTE));
    now.set(Calendar.SECOND, dob.get(Calendar.SECOND));

    long dobSeconds = dob.getTimeInMillis() / MILLISECONDS_IN_SECOND;
    long nowSeconds = now.getTimeInMillis() / MILLISECONDS_IN_SECOND;

    long diff = dobSeconds - nowSeconds;

    return (int) (diff / SECONDS_IN_DAY);
}

/**
 * Deteremines the date of this persons next birthday.
 *
 * @param dobString
 * @return The next birthday
 */
public static String getNextBirthday(String dobString) {
    Calendar dob = getCalendarFromString(dobString);
    Calendar now = Calendar.getInstance();

    dob.set(Calendar.YEAR, now.get(Calendar.YEAR));

    if (!dob.before(now)) {
        StringBuffer sbuffer = new StringBuffer();

        int year = dob.get(Calendar.YEAR);
        int month = dob.get(Calendar.MONTH) + 1;
        int day = dob.get(Calendar.DAY_OF_MONTH);

        sbuffer.append(year);
        sbuffer.append('-');
        if (month < 10)
            sbuffer.append('0');
        sbuffer.append(month);
        sbuffer.append('-');
        if (day < 10)
            sbuffer.append('0');
        sbuffer.append(day);

        return sbuffer.toString();
    } else {
        StringBuffer sbuffer = new StringBuffer();

        int year = dob.get(Calendar.YEAR) + 1;
        int month = dob.get(Calendar.MONTH) + 1;
        int day = dob.get(Calendar.DAY_OF_MONTH);

        sbuffer.append(year);
        sbuffer.append('-');
        if (month < 10)
            sbuffer.append('0');
        sbuffer.append(month);
        sbuffer.append('-');
        if (day < 10)
            sbuffer.append('0');
        sbuffer.append(day);

        return sbuffer.toString();
    }
}

/**
 * Get a Calendar object from a date string (YYYY-MM-DD)
 * Processess a date string (YYYY-MM-DD) into a Calendar object and returns
 * to calling method.
 *
 * @param dateString The string to create the Calendar from
 * @return The Calendar object created from the date string given.
 */
public static Calendar getCalendarFromString(String dateString) {
    Calendar dateCal = Calendar.getInstance();
    dateCal.clear();
    dateCal.set(Integer.parseInt(dateString.substring(0, 3)), Integer.parseInt(dateString.substring(4, 7)), Integer.parseInt(dateString.substring(8, 10)));

    return dateCal;
}

    Process: com.techchai.reminder, PID: 3324
    java.lang.NumberFormatException: Invalid int: "Apr"
            at java.lang.Integer.invalidInt(Integer.java:138)
            at java.lang.Integer.parse(Integer.java:410)
            at java.lang.Integer.parseInt(Integer.java:367)
            at java.lang.Integer.parseInt(Integer.java:334)
            at com.techchai.reminder.activity.BirthdayFragment.getCalendarFromString(BirthdayFragment.java:293)
            at com.techchai.reminder.activity.BirthdayFragment.getNextBirthday(BirthdayFragment.java:238)
            at com.techchai.reminder.activity.BirthdayFragment.getDaysLeft(BirthdayFragment.java:216)
            at com.techchai.reminder.activity.BirthdayFragment$DataAdapter.bindView(BirthdayFragment.java:199)
            at android.widget.CursorAdapter.getView(CursorAdapter.java:254)
            at android.widget.AbsListView.obtainView(AbsListView.java:2823)
            at android.widget.ListView.makeAndAddView(ListView.java:1889)
            at android.widget.ListView.fillDown(ListView.java:713)
            at android.widget.ListView.fillFromTop(ListView.java:779)
            at android.widget.ListView.layoutChildren(ListView.java:1698)
            at android.widget.AbsListView.onLayout(AbsListView.java:2627)
            at android.view.View.layout(View.java:16701)
            at android.view.ViewGroup.layout(ViewGroup.java:5328)
            at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1077)
            at android.view.View.layout(View.java:16701)
            at android.view.ViewGroup.layout(ViewGroup.java:5328)
            at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573)
            at android.widget.FrameLayout.onLayout(FrameLayout.java:508)
            at android.view.View.layout(View.java:16701)
            at android.view.ViewGroup.layout(ViewGroup.java:5328)
            at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1702)
            at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1556)
            at android.widget.LinearLayout.onLayout(LinearLayout.java:1465)
            at android.view.View.layout(View.java:16701)
            at android.view.ViewGroup.layout(ViewGroup.java:5328)
            at android.support.v4.widget.DrawerLayout.onLayout(DrawerLayout.java:907)
            at android.view.View.layout(View.java:16701)
            at android.view.ViewGroup.layout(ViewGroup.java:5328)
            at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573)
            at android.widget.FrameLayout.onLayout(FrameLayout.java:508)
            at android.view.View.layout(View.java:16701)
            at android.view.ViewGroup.layout(ViewGroup.java:5328)
            at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573)
            at android.widget.FrameLayout.onLayout(FrameLayout.java:508)
            at android.view.View.layout(View.java:16701)
            at android.view.ViewGroup.layout(ViewGroup.java:5328)
            at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573)
            at android.widget.FrameLayout.onLayout(FrameLayout.java:508)
            at android.view.View.layout(View.java:16701)
            at android.view.ViewGroup.layout(ViewGroup.java:5328)
            at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1702)
            at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1556)
            at android.widget.LinearLayout.onLayout(LinearLayout.java:1465)
            at android.view.View.layout(View.java:16701)
            at android.view.ViewGroup.layout(ViewGroup.java:5328)
            at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573)
            at android.widget.FrameLayout.onLayout(FrameLayout.java:508)
            at android.view.View.layout(View.java:16701)
            at android.view.ViewGroup.layout(ViewGroup.java:5328)
            at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2344)
            at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2057)
            at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1216)
            at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6678)
            at android.view.Choreographer$CallbackRecord.run(Choreographer.java:777)
            at android.view.Choreographer.doCallbacks(Choreographer.java:590)
            at android.view.Choreographer.doFrame(Choreographer.java:560)
            at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:763)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(L

推荐答案

只需使用Java Calendar 类

Calendar calendar = Calendar.getInstance();
calendar.setTime(birthdayDate);
calendar.add(Calendar.YEAR, 1); // Add one year
Date nextYear = cal.getTime();

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