timeutil.java

来自「Struts2 + Spring JPA Hibernate demo.」· Java 代码 · 共 161 行

package com.vegeta.utils;

import java.text.DateFormat;
import java.text.ParseException;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;

public class TimeUtil {

	private boolean valid = false;

	private int hour = 0;
	private int minute = 0;
	private int amOrPm = 0;

	private static final int INVALID = -1;

	/**
	 * Constructor. Creates a valid TimeUtil object.
	 * 
	 * @param time
	 *            the time as a string.
	 */
	public TimeUtil(String time) {
		parseTime(time);
	}

	/**
	 * Non-argument constructor to help unit testing.
	 */
	protected TimeUtil() {
	}

	protected void parseTime(String time, Locale locale) {
		if (time != null) {
			final String lowerCaseTime = time.toLowerCase();
			int ampmIndex = lowerCaseTime.indexOf("am");
			if (ampmIndex == INVALID) {
				ampmIndex = lowerCaseTime.indexOf("pm");
			}
			int timeEnd = lowerCaseTime.indexOf(' ');
			if (timeEnd == INVALID) {
				timeEnd = ampmIndex != INVALID ? ampmIndex : time.length();
			}
			StringBuffer timeBuffer = new StringBuffer(time.substring(0,
					timeEnd));
			if (lowerCaseTime.indexOf(':') == INVALID) {
				timeBuffer.append(":00");
			}
			if (ampmIndex != INVALID) {
				timeBuffer.append(' ');
				timeBuffer.append(time.substring(ampmIndex));
			}
			try {
				DateFormat df = DateFormat.getTimeInstance(DateFormat.SHORT,
						locale);
				df.setLenient(false);
				Date parsed = df.parse(timeBuffer.toString());
				Calendar cal = Calendar.getInstance();
				cal.setTime(parsed);
				this.amOrPm = cal.get(Calendar.AM_PM);
				this.hour = cal.get(Calendar.HOUR_OF_DAY);
				this.minute = cal.get(Calendar.MINUTE);
				this.valid = true;
			} catch (ParseException e) {
				this.valid = false;
			}
		}
	}

	protected void parseTime(String time) {
		parseTime(time, Locale.getDefault());
	}

	/**
	 * Validates that the time is valid.
	 * <ul>
	 * <li>required: A digit 0..12 / 0..24 depending on Locale</li>
	 * <li>optional: a colon and digit 00..59</li>
	 * <li>optional: space</li>
	 * <li>depending on Locale: case insensitive, either "am" or "pm" for 12
	 * hour formats, empty for 24 hour formats</li>
	 * </ul>
	 * 
	 * Example:
	 * <ul>
	 * <li>12:30 am</li>
	 * <li>12:30pm</li>
	 * <li>9</li>
	 * <li>21:00</li>
	 * </ul>
	 * 
	 * @return true if valid, otherwise false.
	 */
	public boolean isValid() {
		return valid;
	}

	/**
	 * Returns the hour of day in 24 hour scale.
	 * 
	 * @return the hour
	 */
	public int getHour() {
		return hour;
	}

	/**
	 * Returns the hour in 12 hour scale.
	 * 
	 * @return the hour
	 */
	public int getHourAmPm() {
		return hour % 12;
	}

	/**
	 * Returns the minute.
	 * 
	 * @return the minute
	 */
	public int getMinute() {
		return minute;
	}

	/**
	 * Returns whether this is an Calendar.AM or Calendar.PM time.
	 * 
	 * @return either Calendar.AM or Calendar.PM
	 */
	public int getAmOrPm() {
		return amOrPm;
	}

	protected Date resolveDate(Date baseDate, int offset, int hour, int minute)
			throws ParseException {
		if (baseDate != null) {
			Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("GMT+0"));
			cal.setTime(baseDate);
			StringBuffer sb = new StringBuffer("GMT");
			if (offset >= 0) {
				sb.append("+");
			}
			sb.append(offset);
			cal.setTimeZone(TimeZone.getTimeZone(sb.toString()));
			cal.set(Calendar.HOUR_OF_DAY, hour);
			cal.set(Calendar.MINUTE, minute);
			return cal.getTime();
		} else {
			return null;
		}
	}

	public Date resolveDate(Date baseDate, int offset) throws ParseException {
		return resolveDate(baseDate, offset, this.hour, this.minute);
	}

}