Java: Datum (nächster Tag)

Question

Im Rahmen einer College-Aufgabe erhielten wir eine Date-Klasse und wurden aufgefordert, einige Änderungen vorzunehmen. Stuck auf der nextDay() -Methode, und warum es nicht implementieren wird. Ich habe eine Testklasse und verstehe, wie das funktioniert, also ist es genau das Code-Snippet. Jede Hilfe und/oder Erklärungen geschätzt

public class Date 
{ 
private int month; // 1-12 
private int day; // 1-31 based on month 
private int year; // any year 

private static final int[] daysPerMonth = // days in each month 
    { 0,31,28,31,30,31,30,31,31,30,31,30,31 }; 

//constructor: call checkMonth to confirm proper value for month 
//call checkDay to confirm proper value for day 
public Date(int theDay, int theMonth, int theYear) 
{ 
    month = checkMonth(theMonth);//validate moth 
    year = theYear; // could validate year 
    day = checkDay(theDay); //validate day 

    System.out.printf(
     "Date object constructor for date %s\n", this); 
}// end Date constructor 

//method to return day 
public int getDay() 
{ 
    return day; 
}// end method getDay 

// method to return month 
public int getMonth() 
{ 
    return month; 
}//end method getMonth 

//method to get year 
public int getYear() 
{ 
    return year; 
}//end method getYear 

//utility method to confirm proper month value 
private int checkMonth(int testMonth) 
{ 
    if (testMonth > 0 && testMonth <= 12) //validate month 
     return testMonth; 
    else // month is invalid 
     throw new IllegalArgumentException(" month must be 1-12"); 
}// end method check month 

// utilty method to confirm proper day value based on month and year 
private int checkDay(int testDay) 
{ 
    // check if day in range for month 
    if (testDay > 0 && testDay <= daysPerMonth[ month ]) 
     return testDay; 

    if (month == 2 && testDay == 29 && (year % 400 == 0 || 
     (year % 4 == 0 && year % 100 != 0))) 
     return testDay; 

    throw new IllegalArgumentException(
     "day out of range for the specified month and year"); 
}// end method check day 

public String toString() 
{ 
    return String.format("%d-%d-%d", day, month, year); 
}// end method toString 

public void setDate (int d, int m, int y) 
{ 
    setDay(d); 
    setMonth(m); 
    setYear(y); 

} 

public void setDay(int d) 
{ 
    // check if day in range for month 
    if (d > 0 && d <= daysPerMonth[ month ]) 
     day = d; 

    if (month == 2 && d == 29 && (year % 400 == 0 || 
     (year % 4 == 0 && year % 100 != 0))) 
     day = d; 

    throw new IllegalArgumentException(
     "day out of range for the specified month and year"); 

} 

public void setMonth(int m) 
{ 
    if (m> 0 && m <= 12) //validate month 
     month = m; 
    else // month is invalid 
     throw new IllegalArgumentException(" month must be 1-12"); 
} 

public void setYear(int y) 
{ 
    year = y; 
} 

public String toString2() 
{ 
    return String.format("%2d - %2d - %4d ", getDay(), getMonth(), getYear()); 
} 

public void nextDay() 
{ 
    getDay(); 
    day = day++; 
    return day; 

    //if(d = daysPerMonth[ month ]) 
     // return day = 1 && month++; 

    //else if(m = 2 && d = 28) 
     // return day++ && m= 2; 

    //else if(m = 12 && d = 31) 
     // return m = 1 && d = 1 ; 

} 

}

// end class Datum

Answer 1

Ich weiß, dass Sie diesen Code haben aber schon geschrieben gibt es eine viel bessere Möglichkeit, so etwas wie das zu tun.

public Date timeUpdate(Date time){ 
    //time would be the date you want 
    //new Date() creates a new date and within the parentheses is a timestamp allowing 
    //you to set the time with an addition of time in milliseconds 
    //This code basically adds 1 second to the time 

    return new Date(time.getTime()+1000); 

    //for a day change inside the parentheses to (time.getTime()+(1000*24*60*60); 
}