ComparablePerson.java Source code

Introduction

Here is the source code for ComparablePerson.java

Source

import java.util.Comparator;
import java.util.PriorityQueue;
import java.util.Queue;

class ComparablePerson implements Comparable<ComparablePerson> {
    private int id;
    private String name;

    public ComparablePerson(int id, String name) {
        this.id = id;
        this.name = name;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    @Override
    public boolean equals(Object o) {
        if (!(o instanceof ComparablePerson)) {
            return false;
        }
        ComparablePerson p = (ComparablePerson) o;
        if (this.id == p.getId()) {
            return true;
        }

        return false;
    }

    @Override
    public int hashCode() {
        return this.id;
    }

    @Override
    public String toString() {
        return "(" + id + ", " + name + ")";
    }

    @Override
    public int compareTo(ComparablePerson cp) {

        int cpId = cp.getId();
        String cpName = cp.getName();

        if (this.getId() < cpId) {
            return -1;
        }

        if (this.getId() > cpId) {
            return 1;
        }

        if (this.getId() == cpId) {
            return this.getName().compareTo(cpName);
        }

        // Should not reach here
        return 0;
    }
}

public class Main {
    public static void main(String[] args) {
        int initialCapacity = 5;
        Comparator<ComparablePerson> nameComparator = Comparator.comparing(ComparablePerson::getName);

        Queue<ComparablePerson> pq = new PriorityQueue<>(initialCapacity, nameComparator);
        pq.add(new ComparablePerson(1, "Oracle"));
        pq.add(new ComparablePerson(4, "XML"));
        pq.add(new ComparablePerson(2, "HTML"));
        pq.add(new ComparablePerson(3, "CSS"));
        pq.add(new ComparablePerson(4, "Java"));

        System.out.println("Priority  queue: " + pq);

        while (pq.peek() != null) {
            System.out.println("Head  Element: " + pq.peek());
            pq.remove();
            System.out.println("Removed one  element from  Queue");
            System.out.println("Priority  queue: " + pq);
        }
    }
}