EmpComparator.java Source code

Introduction

Here is the source code for EmpComparator.java

Source

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

public class EmpComparator implements Comparator {
    public int compare(Object obj1, Object obj2) {
        Person emp1 = (Person) obj1;
        Person emp2 = (Person) obj2;

        int nameComp = emp1.getFirstName().compareTo(emp2.getFirstName());

        return ((nameComp == 0) ? emp1.getLastName().compareTo(emp2.getLastName()) : nameComp);
    }

    public static void main(String args[]) {
        String names[] = { "Bart", "Hugo", "Lisa", "Marge", "Homer", "Maggie", "Roy" };

        // Convert to list
        List list = new ArrayList(Arrays.asList(names));

        // Ensure list sorted
        Collections.sort(list);
        System.out.println("Sorted list: [length: " + list.size() + "]");
        System.out.println(list);

        // Search for element in list
        int index = Collections.binarySearch(list, "Maggie");
        System.out.println("Found Maggie @ " + index);

        // Search for element not in list
        index = Collections.binarySearch(list, "Jimbo Jones");
        System.out.println("Didn't find Jimbo Jones @ " + index);

        // Insert
        int newIndex = -index - 1;
        list.add(newIndex, "Jimbo Jones");
        System.out.println("With Jimbo Jones added: [length: " + list.size() + "]");
        System.out.println(list);

        // Min should be Bart
        System.out.println(Collections.min(list));
        // Max should be Roy
        System.out.println(Collections.max(list));

        Comparator comp = Collections.reverseOrder();

        // Reversed Min should be Roy
        System.out.println(Collections.min(list, comp));
        // Reversed Max should be Bart
        System.out.println(Collections.max(list, comp));
    }
}

class Person implements Comparable {
    String firstName, lastName;

    public Person(String f, String l) {
        this.firstName = f;
        this.lastName = l;
    }

    public String getFirstName() {
        return firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public String toString() {
        return "[ name=" + firstName + ",name=" + lastName + "]";
    }

    public int compareTo(Object obj) {
        Person emp = (Person) obj;
        int deptComp = firstName.compareTo(emp.getFirstName());

        return ((deptComp == 0) ? lastName.compareTo(emp.getLastName()) : deptComp);
    }

    public boolean equals(Object obj) {
        if (!(obj instanceof Person)) {
            return false;
        }
        Person emp = (Person) obj;
        return firstName.equals(emp.getFirstName()) && lastName.equals(emp.getLastName());
    }

}