Android Calendar Set modify(Calendar val, int field, boolean round)

Description

modify

Declaration

private static void modify(Calendar val, int field, boolean round) 

Method Source Code

import java.sql.Time;
import java.sql.Timestamp;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.TimeZone;

public class Main{
    public final static int SEMI_MONTH = 1001;
    private static final int[][] FIELDS = { { Calendar.MILLISECOND },
            { Calendar.SECOND }, { Calendar.MINUTE },
            { Calendar.HOUR_OF_DAY, Calendar.HOUR },
            { Calendar.DATE, Calendar.DAY_OF_MONTH, Calendar.AM_PM },
            { Calendar.MONTH, DateTimeUtils.SEMI_MONTH },
            { Calendar.YEAR }, { Calendar.ERA } };
    private static void modify(Calendar val, int field, boolean round) {
        if (val.get(Calendar.YEAR) > 280000000) {
            throw new ArithmeticException(
                    "Calendar value too large for accurate calculations");
        }//w w w. jav  a2 s  .  c  o m

        if (field == Calendar.MILLISECOND) {
            return;
        }
        Date date = val.getTime();
        long time = date.getTime();
        boolean done = false;

        int millisecs = val.get(Calendar.MILLISECOND);
        if (!round || millisecs < 500) {
            time = time - millisecs;
            if (field == Calendar.SECOND) {
                done = true;
            }
        }

        int seconds = val.get(Calendar.SECOND);
        if (!done && (!round || seconds < 30)) {
            time = time - (seconds * 1000L);
            if (field == Calendar.MINUTE) {
                done = true;
            }
        }
        int minutes = val.get(Calendar.MINUTE);
        if (!done && (!round || minutes < 30)) {
            time = time - (minutes * 60000L);
        }

        if (date.getTime() != time) {
            date.setTime(time);
            val.setTime(date);
        }
        boolean roundUp = false;
        for (int i = 0; i < FIELDS.length; i++) {
            for (int j = 0; j < FIELDS[i].length; j++) {
                if (FIELDS[i][j] == field) {
                    if (round && roundUp) {
                        if (field == DateTimeUtils.SEMI_MONTH) {
                            if (val.get(Calendar.DATE) == 1) {
                                val.add(Calendar.DATE, 15);
                            } else {
                                val.add(Calendar.DATE, -15);
                                val.add(Calendar.MONTH, 1);
                            }
                        } else {
                            val.add(FIELDS[i][0], 1);
                        }
                    }
                    return;
                }
            }
            int offset = 0;
            boolean offsetSet = false;

            if (field == DateTimeUtils.SEMI_MONTH
                    && FIELDS[i][0] == Calendar.DATE) {
                offset = val.get(Calendar.DATE) - 1;
                if (offset >= 15) {
                    offset -= 15;
                }
                roundUp = offset > 7;
                offsetSet = true;
            } else if (field == Calendar.AM_PM
                    && FIELDS[i][0] == Calendar.HOUR_OF_DAY) {
                offset = val.get(Calendar.HOUR_OF_DAY);
                if (offset >= 12) {
                    offset -= 12;
                }
                roundUp = offset > 6;
                offsetSet = true;
            }

            if (!offsetSet) {
                int min = val.getActualMinimum(FIELDS[i][0]);
                int max = val.getActualMaximum(FIELDS[i][0]);
                offset = val.get(FIELDS[i][0]) - min;
                roundUp = offset > ((max - min) / 2);
            }
            if (offset != 0) {
                val.set(FIELDS[i][0], val.get(FIELDS[i][0]) - offset);
            }
        }
        throw new IllegalArgumentException("The field " + field
                + " is not supported");

    }
    public static Timestamp add(Date date, int calendarField, int amount) {
        if (date == null) {
            throw new IllegalArgumentException("The date must not be null");
        }
        Calendar c = Calendar.getInstance();
        c.setTime(date);
        c.add(calendarField, amount);
        return new Timestamp(c.getTimeInMillis());
    }
}

Related

1. setTo2359(Calendar c)
2. setToDec31(Calendar c)
3. prepareCalendar(int hourOfDay, int minute)
4. toDateTime(Calendar calendar)
5. stripTime(Calendar cal)
6. setDate(Calendar cal, long date)