UTC日期

public static final int DATE = 1;
public static final int TIME = 2;
public static final int DATE_TIME = 3;

private static void dd(StringBuffer buf, int i) {
buf.append((char) (((int) '0') + i / 10));
buf.append((char) (((int) '0') + i % 10));
}

public static String dateToString(Date date, int type) {

Calendar c = Calendar.getInstance();
c.setTimeZone(TimeZone.getTimeZone("GMT"));
c.setTime(date);

StringBuffer buf = new StringBuffer();

if ((type & DATE) != 0) {
int year = c.get(Calendar.YEAR);
dd(buf, year / 100);
dd(buf, year % 100);
buf.append('-');
dd(buf, c.get(Calendar.MONTH) - Calendar.JANUARY + 1);
buf.append('-');
dd(buf, c.get(Calendar.DAY_OF_MONTH));

if (type == DATE_TIME)
buf.append("T");
}

if ((type & TIME) != 0) {
dd(buf, c.get(Calendar.HOUR_OF_DAY));
buf.append(':');
dd(buf, c.get(Calendar.MINUTE));
buf.append(':');
dd(buf, c.get(Calendar.SECOND));
buf.append('.');
int ms = c.get(Calendar.MILLISECOND);
buf.append((char) (((int) '0') + (ms / 100)));
dd(buf, ms % 100);
buf.append('Z');
}

return buf.toString();
}

public static Date stringToDate(String text, int type) {

Calendar c = Calendar.getInstance();

if (type != DATE_TIME)
c.setTime(new Date(0));

if ((type & DATE) != 0) {
c.set(Calendar.YEAR, Integer.parseInt(text.substring(0, 4)));
c.set(Calendar.MONTH, Integer.parseInt(text.substring(5, 7)) - 1
+ Calendar.JANUARY);
c.set(Calendar.DAY_OF_MONTH,
Integer.parseInt(text.substring(8, 10)));

if (type == DATE_TIME)
text = text.substring(11);
}

if ((type & TIME) == 0)
return c.getTime();

c.set(Calendar.HOUR_OF_DAY, Integer.parseInt(text.substring(0, 2))); // -11
c.set(Calendar.MINUTE, Integer.parseInt(text.substring(3, 5)));
c.set(Calendar.SECOND, Integer.parseInt(text.substring(6,));

int pos = 8;
if (pos < text.length() && text.charAt(pos) == '.') {
int ms = 0;
int f = 100;
while (true) {
char d = text.charAt(++pos);
if (d < '0' || d > '9')
break;
ms += (d - '0') * f;
f /= 10;
}
c.set(Calendar.MILLISECOND, ms);
} else
c.set(Calendar.MILLISECOND, 0);

if (pos < text.length()) {

if (text.charAt(pos) == '+' || text.charAt(pos) == '-')

c.setTimeZone(TimeZone.getTimeZone("GMT" + text.substring(pos)));

/*
* return new Date (c.getTime ().getTime () + (Integer.parseInt
* (text.substring (pos+1, pos+3)) * 60 + Integer.parseInt
* (text.substring (pos+4, pos+6))) (text.charAt (pos) == '-' ?
* -60000 : 60000));
*/

else if (text.charAt(pos) == 'Z')
c.setTimeZone(TimeZone.getTimeZone("GMT"));
else
throw new RuntimeException("illegal time format!");
}

return c.getTime();
}

/**
* 取得当月天数
* */ 
public static int getCurrentMonthLastDay() 
{ 
    Calendar a = Calendar.getInstance(); 
    a.set(Calendar.DATE, 1);//把日期设置为当月第一天 
    a.roll(Calendar.DATE, -1);//日期回滚一天，也就是最后一天 
    int maxDate = a.get(Calendar.DATE); 
    return maxDate; 
} 
 
/**
* 得到指定月的天数
* */ 
public static int getMonthLastDay(int year, int month) 
{ 
    Calendar a = Calendar.getInstance(); 
    a.set(Calendar.YEAR, year); 
    a.set(Calendar.MONTH, month - 1); 
    a.set(Calendar.DATE, 1);//把日期设置为当月第一天 
    a.roll(Calendar.DATE, -1);//日期回滚一天，也就是最后一天 
    int maxDate = a.get(Calendar.DATE); 
    return maxDate; 
}

//返回当前年份 
public static int getYear() 
    { 
        Date date = new Date(); 
        String year = new SimpleDateFormat("yyyy").format(date); 
        return Integer.parseInt(year); 
    } 
 
    //返回当前月份 
public static int getMonth() 
    { 
        Date date = new Date(); 
        String month = new SimpleDateFormat("MM").format(date); 
        return Integer.parseInt(month); 
    }