Contact.java

import java.io.Serializable;
import java.util.Objects;

public class Contact implements Serializable {
    private static final long serialVersionUID = 1L;
    private String id;
    private String name;
    private String phone;
    private String email;
    private String address;

    public Contact(String id, String name, String phone, String email, String address) {
        this.id = id;
        this.name = name;
        this.phone = phone;
        this.email = email;
        this.address = address;
    }

    // Getters
    public String getId() { return id; }
    public String getName() { return name; }
    public String getPhone() { return phone; }
    public String getEmail() { return email; }
    public String getAddress() { return address; }

    // Setters
    public void setName(String name) { this.name = name; }
    public void setPhone(String phone) { this.phone = phone; }
    public void setEmail(String email) { this.email = email; }
    public void setAddress(String address) { this.address = address; }

    @Override
    public String toString() {
        return String.format("ID: %s | Name: %s | Phone: %s | Email: %s | Address: %s",
                id, name, phone, email, address);
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Contact contact = (Contact) o;
        return Objects.equals(id, contact.id);
    }

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