CODEWITHSUNDEEP
javasortingoop
AleXzpm
AleXzpm

Reputation: 1074

call compareTo method java issuess

I am trying to build a method to sort an object property, in this example is nrPagPublicate and the method is called compareTo. How do I have to call it? Is my interface ok? This is where I`m stuck:

import java.util.Arrays;
/**
 *
 * @author alex
 */
public class Autor implements Comparable<Autor> {

   /**
    * @param args the command line arguments
    */
    public String nume;
    private int nrPagPublicate;
    private final int masa = 22;
    //contrusctor obiecte
    public Autor(String nume, int nrPagPublicate){
        this.nume = nume;
        this.nrPagPublicate = nrPagPublicate;     
    }
    public void vorb(){
        System.out.println(nume + " asa ma cheama pe mine!");
    }
    //setters and gettters
    public String getNume() {
        return nume;
    }

    public void setNume(String nume) {
        this.nume = nume;
    }

    public int getNrPagPublicate() {
        return nrPagPublicate;
    }
    public int compareTo(Autor CompareAutor) {
        int comparenrPagPublicate = ((Autor)    CompareAutor).getNrPagPublicate(); 
    //ascending order
    return this.nrPagPublicate - comparenrPagPublicate;
    //descending order
    //return compareQuantity - this.quantity;        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }
    public void setNrPagPublicate(int nrPagPublicate) {
        this.nrPagPublicate = nrPagPublicate;
    }
    //constructor de copiere
    public Autor(Autor c){
        nume = c.nume;
        nrPagPublicate = c.nrPagPublicate;
    }


    public static void main(String[] args) {
        // TODO code application logic here
        Autor ion = new Autor("ion",23);
        Autor ion2 = new Autor("ion2",2);
        compareTo();
    } 
}

amd in my interface i have 

public interface Comparable<Autor> {
    public int compareTo(Autor CompareAutor);
}

Upvotes: 0

Views: 1440

Answers (1)

Zbynek Vyskovsky - kvr000
Zbynek Vyskovsky - kvr000

Reputation: 18865

You have two options - either implement Comparable intergace or write standalone Comparator interface.

Both options are well described at http://www.mkyong.com/java/java-object-sorting-example-comparable-and-comparator/ .

You can then put the items into array and sort using Arrays class: 

Author[] authors = new Author[]{ ion, ion2, ion3, ... };
Arrays.sort(authors);
// now you would see the ion2 as first element in the array, ion as second element etc.

Upvotes: 1

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