Java：日期（第二天）

Question

作爲大學作業的一部分，我們給了一個Date類並告知做出一些修改。堅持nextDay（）方法，以及爲什麼它不會實現。我有一個測試類，並瞭解它如何工作，以便它只是代碼片段。任何幫助和/或解釋讚賞

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 ; 

} 

}

//結束類日期

Answer 1

我知道你有這樣的代碼已經編寫但是有做這樣的事情的一個更好的方法。

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); 
}