Question

maybe anybody could help me out. i’m working with Data access object.
i have a database:
table Receiverz

num   name
 1    Walmart
 2    Target
 3    McDonalds

i’ve created a class for this table

public class Receiverz {
private int num;
private String name;

public void setNum(int num) {
    this.num = num;
}

public void setName(String name) {
    this.name = name;
}

}

then i created Dao interface and passed a method to it:

public interface Dao {

Receiverz getReceiverz(int num);}

Then i created a class ExpensesDao that implements Dao and created a singleton in it(i aslo set up the connection with database but i will skip that part) and overrode getReceivers(int num) method by making it possible to work with database:

public class ExpensesDao implements Dao {

private static Dao thisdao;
public static synchronized Dao getDao() {
    if (thisdao==null) {
        thisdao = new ExpensesDao();
    }
    return thisdao;
    }

@Override
public Receiverz getReceiverz(int num) {
    Receiverz receiver = new Receiverz();
    try {
        Statement stmt = myConnection.createStatement();
        ResultSet result = stmt.executeQuery("SELECT * FROM receiverz");
        while(result.next()){

            receiver.setNum(num);
            receiver.setName(result.getString(2));

            }

    }
        catch (SQLException e){
             System.out.println(e.getMessage());
         }
    return receiver;

}

when i try to run it in main class:

public class TryDatabase {

public static void main(String[] args) {
    Dao ex = ExpensesDao.getDao(); 
    System.out.println(ex.getReceiverz(2));

all i get is:

listexpenses.Receiverz@193499fd

but i have to get

2 Target

(since i passed 2 in the parameters and it refers to Target in my database.
does anyone know what’s going wrong and what i should change in my code. P.S. i hope i made it clear enough.

Answer 1

ex.getReceiverz(2) is returning a Receiverz object. Thus the System.out.println(ex.getReceiverz(2)); is using the toString() method inherited from java.lang.Object. Create a toString() method in the Receiverz class that will output it the way you want.