Women in Technology

Article:		Making Java Objects Comparable
Subject:		Regarding sorting of objects
Date:		2006-05-10 22:19:48
From:		Quetion
HI, This article is good.. But i am not getting how to sort the objects based on two conditons simultaneously. For example if i want to sort the emp details based on first name and age. The condition is the first sort the objects inbetween age group 20-30 and within that group sort alphabetically. please will you send a soulution for this.. waiting for your reply... thank you Regards Anirudhkumar

Showing messages 1 through 3 of 3.

• Regarding sorting of objects
  2006-12-20 02:18:03  hirenaik [View]
  
  
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Comparator;
  
  class Person{
  private String empName=null;
  private String empAdd=null;
  private int age=0;
  
  Person(String name, String add){
  empName=name;
  empAdd=add;
  }
  public String getEmpAdd() {
  return empAdd;
  }
  public String getEmpName() {
  return empName;
  }
  public void setEmpAdd(String string) {
  empAdd = string;
  }
  public void setEmpName(String string) {
  empName = string;
  }
  
  static Comparator sortByEmpName = new Comparator(){
  public int compare(Object person, Object anotherPerson) {
  String empName1 = ((Person) person).getEmpName();
  String empName2 = ((Person) anotherPerson).getEmpName();
  String empAdd1 = ((Person)person).getEmpAdd();
  String empAdd2 = ((Person)anotherPerson).getEmpAdd();
  System.out.println("sorting");
  if(!empName1.equals(empName2))
  return empName1.compareTo(empName2);
  else
  return empAdd1.compareTo(empAdd2);
  }
  };
  
  static Comparator sortByEmpAdd = new Comparator(){
  public int compare(Object person, Object anotherPerson) {
  String empName1 = ((Person) person).getEmpName();
  String empName2 = ((Person) anotherPerson).getEmpName();
  String empAdd1 = ((Person)person).getEmpAdd();
  String empAdd2 = ((Person)anotherPerson).getEmpAdd();
  System.out.println("sorting");
  if(!empAdd1.equals(empAdd2))
  return empAdd1.compareTo(empAdd2);
  else
  return empName1.compareTo(empName2);
  }
  };
  
  public String toString(){
  return empName + ":"+ empAdd;
  }
  }
  
  public class MyCollection{
  public MyCollection() {
  super();
  }
  public static void main(String[] args) {
  ArrayList a = new ArrayList();
  
  Person p = new Person("A","C");
  a.add(p);
  p=null;
  
  p = new Person("A","A");
  a.add(p);
  p=null;
  
  p = new Person("C","B");
  a.add(p);
  p=null;
  Object[] o = a.toArray();
  
  Arrays.sort(o,Person.sortByEmpName);
  
  for(int i =0; i System.out.println((Person)o[i]);
  
  }
  }
  
  
  I think you can check this programm. you will get help from it.

• Regarding sorting of objects
  2006-11-28 23:26:24  raoul.schmidiger [View]
  
  
  Delegate the compareTo to Strings implementation:
  
  
public int compareTo(Object o) {
...
return this.getText().compareTo(o.getText());

  
  Regards Raoul
• Regarding sorting of objects
  2006-11-29 01:14:09  raoul.schmidiger [View]
  
  
  for sorting with 2 criterias, you will have to first sort by one criteria and then within each "element" do a second sort with the other criteria.
  
  sort1: 1, 2, 3 ... n
  sort2 1: a, b, c ..., z
  sort2 2: a, b, c ..., z
  sort2 3: a, b, c ..., z
  sort2 ...: a, b, c ..., z
  sort2 n: a, b, c ..., z
  
  Easy...