Convertion of user-defined object to string by toString not showing correct output

Question

I have created a class CurrentDate which shows the system date in a particular format(e.g. 29-JUN-12). The class looks like :

package getset;

import java.util.*;
import getset.Getset;
public class CurrentDate{
    public static void main(String[] args){
        Calendar cal = new GregorianCalendar();
        int month = cal.get(Calendar.MONTH);
        int year = cal.get(Calendar.YEAR);
        int day = cal.get(Calendar.DAY_OF_MONTH);

        String toyear=String.valueOf(year);
        String newyear=toyear.substring(2,4);
        String newmonth=monthvalidation(month);
        System.out.println("Current date : " + day + "-" + (newmonth) + "-" + newyear);
    }

    private static String monthvalidation(int initmonth) {
        // TODO Auto-generated method stub
        //int initmonth=i;
        String finalmonth="";
        if(initmonth==1)
        {
            finalmonth="JAN";
        }
        if(initmonth==2)
        {
            finalmonth="FEB";
        }
        if(initmonth==3)
        {
            finalmonth="MAR";
        }
        if(initmonth==4)
        {
            finalmonth="APR";
        }
        if(initmonth==5)
        {
            finalmonth="MAY";
        }
        if(initmonth==6)
        {
            finalmonth="JUN";
        }
        if(initmonth==7)
        {
            finalmonth="JUL";
        }
        if(initmonth==8)
        {
            finalmonth="AUG";
        }
        if(initmonth==9)
        {
            finalmonth="SEP";
        }
        if(initmonth==10)
        {
            finalmonth="OCT";
        }
        if(initmonth==11)
        {
            finalmonth="NOV";
        }
        if(initmonth==12)
        {
            finalmonth="DEC";
        }    
        return finalmonth;
    }
}

Now when I try to convert it using toString() it does not show what is expected. I tried:

CurrentDate date=new CurrentDate();
String sysdate=date.toString();
System.out.println(""+sysdate);

It shows something like: getset.CurrentDate@18a178a which is not human readable expected format. What can I do to correct this?

Answer 1

You need to override the toString method.

In your CurrentDate class, add somethnig like

@Override
public String toString() {
    String toyear=String.valueOf(year);
    String newyear=toyear.substring(2,4);
    String newmonth=monthvalidation(month);
    return day + "-" + newmonth + "-" + newyear;
}

Answer 2

You are not overriding the Object implementation of toString() To test your method, you could quickly put the logic in that you have developed into a public String toString() method. then in your main method, create a CurrentDate and print the toString.

Answer 3

Override toString method in your class . Add a method like a as follows.

@Override
public String toString() {

    return day + "-" + newmonth + "-" + newyear;
}

Answer 4

I see problem in your code. First, you are not having fields for which you want toString() representation.I think you need to declare fields like:

int month;
int year ;
int day;
 @Override
public String toString() {
    return "CurrentDate [month=" + month + ", year=" + year + ", day="
            + day + "]";
}

If you are using Eclipse IDE, just generate toString() method, that will be a simple solution to your problem. Right now, object toString() is invoked for your toString(). In fact, as per Josh Bloch,

every class should override toString() for getting human readable format.

Answer 5

CurrentDate date=new CurrentDate();
String sysdate=date.toString();
System.out.println(""+sysdate);

In your above code you are using date object but not assigning  any value , only CurrentDate  class reference. so your are getting 'getset.CurrentDate@18a178a' when use toString() method.

If you want to format date to string you have to use 

public static final String DATE_FORMAT_NOW = "dd-MMM-yy";

SimpleDateFormat sdf = new SimpleDateFormat(DATE_FORMAT_NOW);