package aa;(不要我也试过,当然Clendar.java里我就不用import aa.*)import java.util.*; import java.io.*;public class Day implements Cloneable, Serializable { /** * Constructs today's date */
public Day() { GregorianCalendar todaysDate = new GregorianCalendar(); year = todaysDate.get(Calendar.YEAR); month = todaysDate.get(Calendar.MONTH) + 1; day = todaysDate.get(Calendar.DAY_OF_MONTH); } /** * Constructs a specific date * @param yyyy year (full year, e.g., 1996, * <i>not</i> starting from 1900) * @param m month * @param d day * @exception IllegalArgumentException if yyyy m d not a * valid date */
public Day(int yyyy, int m, int d) { year = yyyy; month = m; day = d; if (!isValid()) throw new IllegalArgumentException(); }
/** * Advances this day by n days. For example. * d.advance(30) adds thirdy days to d * @param n the number of days by which to change this * day (can be < 0) */
public void advance(int n) { fromJulian(toJulian() + n); } public int getDay() /** * Gets the day of the month * @return the day of the month (1...31) */ { return day; } public int getMonth() /** * Gets the month * @return the month (1...12) */ { return month; } public int getYear() /** * Gets the year * @return the year (counting from 0, <i>not</i> from 1900) */ { return year; }
public int weekday() { return (toJulian() + 1)% 7; }
/** * The number of days between this and day parameter * @param b any date * @return the number of days between this and day parameter * and b (> 0 if this day comes after b) */
public int daysBetween(Day b) { return toJulian() - b.toJulian(); } /** * A string representation of the day * @return a string representation of the day */
public String toString() { return "Day[" + year + "," + month + "," + day + "]"; } /** * Makes a bitwise copy of a Day object * @return a bitwise copy of a Day object */
public Object clone() { try { return super.clone(); } catch (CloneNotSupportedException e) { // this shouldn't happen, since we are Cloneable return null; } } /** * Computes the number of days between two dates * @return true iff this is a valid date */
private boolean isValid() { Day t = new Day(); t.fromJulian(this.toJulian()); return t.day == day && t.month == month && t.year == year; } private int toJulian() /** * @return The Julian day number that begins at noon of * this day * Positive year signifies A.D., negative year B.C. * Remember that the year after 1 B.C. was 1 A.D. * * A convenient reference point is that May 23, 1968 noon * is Julian day 2440000. * * Julian day 0 is a Monday. * * This algorithm is from Press et al., Numerical Recipes * in C, 2nd ed., Cambridge University Press 1992 */ { int jy = year; if (year < 0) jy++; int jm = month; if (month > 2) jm++; else { jy--; jm += 13; } int jul = (int) (java.lang.Math.floor(365.25 * jy) + java.lang.Math.floor(30.6001*jm) + day + 1720995.0); int IGREG = 15 + 31*(10+12*1582); // Gregorian Calendar adopted Oct. 15, 1582 if (day + 31 * (month + 12 * year) >= IGREG) // change over to Gregorian calendar { int ja = (int)(0.01 * jy); jul += 2 - ja + (int)(0.25 * ja); } return jul; } private void fromJulian(int j) /** * Converts a Julian day to a calendar date * @param j the Julian date * This algorithm is from Press et al., Numerical Recipes * in C, 2nd ed., Cambridge University Press 1992 */ { int ja = j;
int JGREG = 2299161; /* the Julian date of the adoption of the Gregorian calendar */ if (j >= JGREG) /* cross-over to Gregorian Calendar produces this correction */ { int jalpha = (int)(((float)(j - 1867216) - 0.25) / 36524.25); ja += 1 + jalpha - (int)(0.25 * jalpha); } int jb = ja + 1524; int jc = (int)(6680.0 + ((float)(jb-2439870) - 122.1) /365.25); int jd = (int)(365 * jc + (0.25 * jc)); int je = (int)((jb - jd)/30.6001); day = jb - jd - (int)(30.6001 * je); month = je - 1; if (month > 12) month -= 12; year = jc - 4715; if (month > 2) --year; if (year <= 0) --year; } private int day; private int month; private int year; }
import java.io.*;public class Day implements Cloneable, Serializable
{ /**
* Constructs today's date
*/
public Day()
{ GregorianCalendar todaysDate
= new GregorianCalendar();
year = todaysDate.get(Calendar.YEAR);
month = todaysDate.get(Calendar.MONTH) + 1;
day = todaysDate.get(Calendar.DAY_OF_MONTH);
} /**
* Constructs a specific date
* @param yyyy year (full year, e.g., 1996,
* <i>not</i> starting from 1900)
* @param m month
* @param d day
* @exception IllegalArgumentException if yyyy m d not a
* valid date
*/
public Day(int yyyy, int m, int d)
{ year = yyyy;
month = m;
day = d;
if (!isValid())
throw new IllegalArgumentException();
}
/**
* Advances this day by n days. For example.
* d.advance(30) adds thirdy days to d
* @param n the number of days by which to change this
* day (can be < 0)
*/
public void advance(int n)
{ fromJulian(toJulian() + n);
} public int getDay()
/**
* Gets the day of the month
* @return the day of the month (1...31)
*/ { return day;
} public int getMonth()
/**
* Gets the month
* @return the month (1...12)
*/ { return month;
} public int getYear()
/**
* Gets the year
* @return the year (counting from 0, <i>not</i> from 1900)
*/ { return year;
}
/**
* Gets the weekday
* @return the weekday (0 = Sunday, 1 = Monday, ...,
* 6 = Saturday)
*/
public int weekday() { return (toJulian() + 1)% 7; }
/**
* The number of days between this and day parameter
* @param b any date
* @return the number of days between this and day parameter
* and b (> 0 if this day comes after b)
*/
public int daysBetween(Day b)
{ return toJulian() - b.toJulian();
} /**
* A string representation of the day
* @return a string representation of the day
*/
public String toString()
{ return "Day[" + year + "," + month + "," + day + "]";
} /**
* Makes a bitwise copy of a Day object
* @return a bitwise copy of a Day object
*/
public Object clone()
{ try
{ return super.clone();
} catch (CloneNotSupportedException e)
{ // this shouldn't happen, since we are Cloneable
return null;
}
} /**
* Computes the number of days between two dates
* @return true iff this is a valid date
*/
private boolean isValid()
{ Day t = new Day();
t.fromJulian(this.toJulian());
return t.day == day && t.month == month
&& t.year == year;
} private int toJulian()
/**
* @return The Julian day number that begins at noon of
* this day
* Positive year signifies A.D., negative year B.C.
* Remember that the year after 1 B.C. was 1 A.D.
*
* A convenient reference point is that May 23, 1968 noon
* is Julian day 2440000.
*
* Julian day 0 is a Monday.
*
* This algorithm is from Press et al., Numerical Recipes
* in C, 2nd ed., Cambridge University Press 1992
*/
{ int jy = year;
if (year < 0) jy++;
int jm = month;
if (month > 2) jm++;
else
{ jy--;
jm += 13;
}
int jul = (int) (java.lang.Math.floor(365.25 * jy)
+ java.lang.Math.floor(30.6001*jm) + day + 1720995.0); int IGREG = 15 + 31*(10+12*1582);
// Gregorian Calendar adopted Oct. 15, 1582 if (day + 31 * (month + 12 * year) >= IGREG)
// change over to Gregorian calendar
{ int ja = (int)(0.01 * jy);
jul += 2 - ja + (int)(0.25 * ja);
}
return jul;
} private void fromJulian(int j)
/**
* Converts a Julian day to a calendar date
* @param j the Julian date
* This algorithm is from Press et al., Numerical Recipes
* in C, 2nd ed., Cambridge University Press 1992
*/
{ int ja = j;
int JGREG = 2299161;
/* the Julian date of the adoption of the Gregorian
calendar
*/ if (j >= JGREG)
/* cross-over to Gregorian Calendar produces this
correction
*/
{ int jalpha = (int)(((float)(j - 1867216) - 0.25)
/ 36524.25);
ja += 1 + jalpha - (int)(0.25 * jalpha);
}
int jb = ja + 1524;
int jc = (int)(6680.0 + ((float)(jb-2439870) - 122.1)
/365.25);
int jd = (int)(365 * jc + (0.25 * jc));
int je = (int)((jb - jd)/30.6001);
day = jb - jd - (int)(30.6001 * je);
month = je - 1;
if (month > 12) month -= 12;
year = jc - 4715;
if (month > 2) --year;
if (year <= 0) --year;
} private int day;
private int month;
private int year;
}
把classpath改成c:\hcj\ 试试
什么symbol 不能识别?
C:\hcj>javac Calendar.java
classone.java:1: package corejavadoes not exist
import corejava.day;
这应是路径问题,请问大哥还要如何设置路径啊