java Calendar

package com.cg.tests;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.TimeZone;

import org.junit.Test;

public class TestCalendar {
	
	@Test
	public void testCalendar(){
		/**按年月日构造日期时间对象**/
		GregorianCalendar cal =new GregorianCalendar(1988, 1, 17);
		
		int iFirstDay = cal.getActualMinimum(Calendar.DAY_OF_MONTH);
		int iLastDay = cal.getActualMaximum(Calendar.DAY_OF_MONTH);
		
		Calendar calFirst =(Calendar) cal.clone();
		Calendar calLast =(Calendar) cal.clone();
				
		calFirst.set(Calendar.DAY_OF_MONTH, iFirstDay);
		calLast.set(Calendar.DAY_OF_MONTH, iLastDay);
		
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
		System.out.println(sdf.format( cal.getTime()));
		System.out.println(sdf.format(calFirst.getTime()));
		System.out.println(sdf.format(calLast.getTime()));
		
		/**时区**/
		Calendar calNow = Calendar.getInstance();		//默认时区当前时间
		System.out.println(sdf.format( calNow.getTime()));
		
		Calendar calGmt0 = Calendar.getInstance(TimeZone.getTimeZone("GMT-10"));
//		calNow.setTimeZone(TimeZone.getTimeZone("GMT+0"));
		System.out.println(sdf.format( calGmt0.getTime()) );
		System.out.println(calNow);
		System.out.println(calGmt0);
		
		System.out.println("Hour of day: "+calNow.get(Calendar.HOUR_OF_DAY));
		System.out.println("Hour of day: "+calGmt0.get(Calendar.HOUR_OF_DAY));
		
		System.out.println(calGmt0.get(Calendar.DAY_OF_MONTH));
		
	}

}