Example Program for using ArrayList and Comparator in java Collections and their Methods

Java Object Sorting using Comparator vs Comparable interface Class.
Java Sorting Comparator vs Comparable interface .
Here we are using for Collections Methods  for Sorting Purpose. and ArrayList for Storing Purpose.....
Write a java program to use the Comparator  and Comparable interface in Java.....
(1) Employee.java

package ComparatorVsComparable;

import java.util.Comparator;


public class Employee   {

    private String empNameId;
    private int empAge;
   
    public Employee() {
       
    }
   
    Employee(String empNameId , int empAge) {
   
       
        this.empNameId = empNameId ;
        this.empAge    = empAge ;
       
    }
   
    public String getName() {
       
        return empNameId;
    }
    public void setName(String empNameId) {
       
        this.empNameId = empNameId;
       
    }
    public int getAge() {
       
        return empAge;
    }
    public void setAge(int empAge) {
       
        this.empAge = empAge;
    }
   
   
}

(2)CompareClassOnly.java
package ComparatorVsComparable;

import java.util.Comparator;

public class CompareClassOnly implements Comparator<Employee> {


   
    @Override
    public int compare(Employee emp1, Employee emp2) { // Compare Numbers
       
        System.out.println(" -----------CompareClassOnly Class Executed with Compare Method -----------");
               
        return emp1.getAge() > emp2.getAge() ? -1 : (emp1.getAge() == emp2.getAge() ? 0 : 1 );
    }

}

(3)CompareStringOnly.java

package ComparatorVsComparable;

import java.util.Comparator;

public class CompareStringOnly implements Comparator<Employee>{

    @Override
    public int compare(Employee o1, Employee o2) {
      
        System.out.println(" -----------CompareStringOnly Class Executed with Compare Method -----------");
      
        String str1 = o1.getName();
        String str2 = o2.getName();
      
        return str1.compareTo(str2);
    }

   
   
   
}
(4) ComparatorMainClass.java

package ComparatorVsComparable;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;



public class ComparatorMainClass {
   
    public static void main(String args[]) {
      
        List<Employee> list = new ArrayList<Employee>();
      
        list.add(new Employee("Hari581", 24));
        list.add(new Employee("Dayanidhi582", 23));
        list.add(new Employee("Athik111", 22));
        list.add(new Employee("Premkumar486", 28));
        list.add(new Employee("Muthu420", 27));
      
        Collections.sort(list , new CompareStringOnly());
        System.out.println(" \n After Collection Default Descending Sorting NameWise Order Details : ");
        for(Employee e : list) {
          
            System.out.println(" EmpNameId : " +e.getName()+"      EmpAge : " + e.getAge());
        }
      
      
        Collections.sort(list , new CompareClassOnly());
        System.out.println(" \n After Collection Default Descending Sorting AgeWise Order Details : ");
        for(Employee e : list) {
          
            System.out.println(" EmpNameId : " +e.getName()+"      EmpAge : " + e.getAge());
        }
      
    }

}


In This Example used to Find the Given Name with Age for Sorting Purpose..
First Sort with Name Wise ( String Sorting )
Second Sort With Age Wise ( Number Sorting)

output::

 -----------CompareStringOnly Class Executed with Compare Method -----------
 -----------CompareStringOnly Class Executed with Compare Method -----------
 -----------CompareStringOnly Class Executed with Compare Method -----------
 -----------CompareStringOnly Class Executed with Compare Method -----------
 -----------CompareStringOnly Class Executed with Compare Method -----------
 -----------CompareStringOnly Class Executed with Compare Method -----------

 After Collection Default Descending Sorting NameWise Order Details :
 EmpNameId : Athik111      EmpAge : 22
 EmpNameId : Dayanidhi582      EmpAge : 23
 EmpNameId : Hari581      EmpAge : 24
 EmpNameId : Muthu420      EmpAge : 27
 EmpNameId : Premkumar486      EmpAge : 28
 -----------CompareClassOnly Class Executed with Compare Method -----------
 -----------CompareClassOnly Class Executed with Compare Method -----------
 -----------CompareClassOnly Class Executed with Compare Method -----------
 -----------CompareClassOnly Class Executed with Compare Method -----------
 -----------CompareClassOnly Class Executed with Compare Method -----------
 -----------CompareClassOnly Class Executed with Compare Method -----------
 -----------CompareClassOnly Class Executed with Compare Method -----------
 -----------CompareClassOnly Class Executed with Compare Method -----------
 -----------CompareClassOnly Class Executed with Compare Method -----------
 -----------CompareClassOnly Class Executed with Compare Method -----------

 After Collection Default Descending Sorting AgeWise Order Details :
 EmpNameId : Premkumar486      EmpAge : 28
 EmpNameId : Muthu420      EmpAge : 27
 EmpNameId : Hari581      EmpAge : 24
 EmpNameId : Dayanidhi582      EmpAge : 23
 EmpNameId : Athik111      EmpAge : 22

Note:: This Program is for mm Own Code.. If you have any Query pls mail to:  vhkrishnan.v@gmail.com