Ciudades - persistencia Curso de Programación Java

Lección:

Persistencia de Objetos


Ejercicio:

Ciudades - persistencia 28


Objetivo:

Cree una nueva versión de la "base de datos de ciudades" (que mejoró el 13 de marzo), utilizando la persistencia para almacenar sus datos en lugar de archivos de texto.


Código:

package PersistenceCities;
public class City implements Serializable
{

	private String name;
	private int inhabitants;

	//CONSTRUCTORS
	public City()
	{

	}

	public City(String name, int inhabitants)
	{
		this.name = name;
		this.inhabitants = inhabitants;
	}

	//GETTERS && SETTERS
	public final String getName()
	{
		return name;
	}
	public final void setName(String value)
	{
		name = value;
	}

	public final int getInhabitants()
	{
		return inhabitants;
	}

	public final void setInhabitants(int value)
	{
		inhabitants = value;
	}

}

package PersistenceCities;
public class Serializador
{
    private String nombre;

	public Serializador(String nombreFich)
	{
		nombre = nombreFich;
	}

	public final void Guardar(City objeto)
	{
		IFormatter formatter = new BinaryFormatter();
		Stream stream = new java.io.FileOutputStream(nombre);
		formatter.Serialize(stream, objeto);
		stream.Close();
	}

	public final City[] Cargar()
	{
		City objeto;
		IFormatter formatter = new BinaryFormatter();
		Stream stream = new java.io.FileInputStream(nombre);
		objeto = (City)formatter.Deserialize(stream);
		stream.Close();
		return objeto;
	}
}

package PersistenceCities;
import java.util.*;

public class Main
{
	public static void main(String[] args)
	{
		ArrayList cities = new ArrayList();

		int currentCityNumber;
		String option;
		String textToSearch;
		boolean found;
		String textToModify;
		boolean finished = false;
		//  City currentCity;
		String line;
		// City newCity;

		City[] city = new City[2000];
		int count = 0;

		if ((new java.io.File("data.dat")).isFile())
		{

			Serializador s = new Serializador("data.dat");
			city = (City[])s.Cargar();
		}

		do
		{
			System.out.println();
			System.out.println("Cities database");
			System.out.println();
			System.out.println("1.- Add a new city");
			System.out.println("2.- View all cities");
			System.out.println("3.- Modify a record");
			System.out.println("4.- Insert a new record");
			System.out.println("5.- Delete a record");
			System.out.println("6.- Search in the records");
			System.out.println("7.- Correct the capitalization of the names");
			System.out.println("0.- Exit");
			System.out.println();
			System.out.print("Choose an option: ");
			option = new Scanner(System.in).nextLine();

			switch (option)
			{
				//0.-Exit
				case "0":
					finished = true;
					break;


				//1 .- Add a new city (at the end of the existing data)
				case "1":
					System.out.printf("Entering data for city number %1$s" + "\r\n", cities.size() + 1);
					System.out.print("Enter the city name: ");
					City newcity = new City();
					newcity.Name = new Scanner(System.in).nextLine();
					System.out.print("Enter the inhabitants numbers: ");
					newcity.Inhabitants = Integer.parseInt(new Scanner(System.in).nextLine());
					cities.add(newcity);
					System.out.println("The data was entered correctly");
					break;


				//2 .- View all cities (name and inhabitants)
				case "2":
					for (int i = 0; i < cities.size(); i++)
					{
						currentCity = (city)cities.get(i);
						System.out.printf("%1$s: %2$s, %3$s inhabitants" + "\r\n", i + 1, currentCity.name, currentCity.inhabitants);
					}
					System.out.println();
					break;


				//3 .- Modify a record (rename and / or change number of inhabitants)
				case "3":
					System.out.print("Enter the city number: ");
					currentCityNumber = Integer.parseInt(new Scanner(System.in).nextLine());
					currentCity = (city)cities.get(currentCityNumber - 1);
					System.out.printf("Enter a new data for a city number: %1$s" + "\r\n", currentCityNumber);
					System.out.printf("City name (was %1$s; hit ENTER to leave as is): ", currentCity.name);
					textToModify = new Scanner(System.in).nextLine();
					if (!textToModify.equals(""))
					{
						currentCity.name = textToModify;
					}
					System.out.printf("Inhabitants (was %1$s; hit ENTER to leave as is): ", currentCity.inhabitants);
					textToModify = new Scanner(System.in).nextLine();
					if (!textToModify.equals(""))
					{
						currentCity.inhabitants = Integer.parseInt(textToModify);
					}
					cities.set(currentCityNumber - 1, currentCity);
					System.out.println();
					break;


				//4 .- Insert a new record (in a specified position,
				//moving the following ones to the right).
				case "4":
					System.out.print("Enter the number of the city to modify: ");
					currentCityNumber = Integer.parseInt(new Scanner(System.in).nextLine());
					currentCity = (city)cities.get(currentCityNumber - 1);
					System.out.printf("Insert a new data at %1$s position: " + "\r\n", currentCityNumber);
					System.out.print("City name: ");
					currentCity.name = new Scanner(System.in).nextLine();
					System.out.print("Inhabitants: ");
					currentCity.inhabitants = Integer.parseInt(new Scanner(System.in).nextLine());
					cities.add(currentCityNumber - 1, currentCity);
					break;


				//5 .- Delete a record (moving the following 
				//  ones to the left so that no empty spaces are left)
				case "5":
					System.out.print("Enter the city number for delete: ");
					currentCityNumber = Integer.parseInt(new Scanner(System.in).nextLine());

					System.out.printf("Deleting the number %1$s" + "\r\n", currentCityNumber);
					cities.remove(currentCityNumber - 1);
					break;


				//6 .- Search in the records (display the ones which contain 
				//a certain text in their name, whether in upper or lower case, 
				//using partial search)
				case "6":
					System.out.print("Enter the text to search: ");
					textToSearch = new Scanner(System.in).nextLine();
					found = false;
					for (int i = 0; i < cities.size(); i++)
					{
						currentCity = (city)cities.get(i);
						if (currentCity.name.toUpperCase().indexOf(textToSearch.toUpperCase()) >= 0)
						{
							System.out.printf("%1$s found in %2$s" + "\r\n", textToSearch, currentCity.name);
							found = true;
						}
					}
					if (!found)
					{
						System.out.println("Not found.");
					}
					break;


				// 7 .- Correct the capitalization of the names
				//(turn into uppercase the first letter and the ones after 
				//a space, and make the rest lowercase).
				case "7":
					for (int i = 0; i < cities.size(); i++)
					{
						currentCity = (city)cities.get(i);
						// First, the whole name to lower case
						String lowerCaseName = currentCity.name.toLowerCase();
						// then, first letter to uppercase
						String correctedName = lowerCaseName.substring(0, 1).toUpperCase() + lowerCaseName.substring(1);
						// and then the letters after a space
						for (int j = 1; j < correctedName.length() - 2; j++)
						{
							if (correctedName.charAt(j) == ' ')
							{
								correctedName = correctedName.substring(0, j) + " " + correctedName.substring(j + 1, j + 1 + 1).toUpperCase() + correctedName.substring(j + 2);
							}
						}

						currentCity.name = correctedName;
					}
					break;


				default:
					System.out.println("Wrong option ");
					break;

			}

		} while (!finished);

		outputFile = File.CreateText("data.dat");

		for (int i = 0; i < cities.size(); i++)
		{
			currentCity = (city)cities.get(i);
			outputFile.WriteLine(currentCity.name);
			outputFile.WriteLine(currentCity.inhabitants);
		}

		outputFile.Close();

	}
}