Przykłady JSON

pom.xml

@@ -16,9 +16,20 @@
 		<dependency>
 			<groupId>org.junit.jupiter</groupId>
 			<artifactId>junit-jupiter-api</artifactId>
-			<version>5.7.1</version>
+			<version>5.7.2</version>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>javax.json</groupId>
+			<artifactId>javax.json-api</artifactId>
+			<version>1.1.4</version>
+		</dependency>
+		<dependency>
+			<groupId>org.glassfish</groupId>
+			<artifactId>javax.json</artifactId>
+			<version>1.1.4</version>
+			<scope>runtime</scope>
+		</dependency>
 	</dependencies>
 
 </project>
\ No newline at end of file

src/test/java/pogoda_json/PogodaDlaMiasta.java

+package pogoda_json;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.util.Scanner;
+
+import javax.json.Json;
+import javax.json.JsonArray;
+import javax.json.JsonObject;
+import javax.json.JsonReader;
+import javax.json.JsonValue;
+
+public class PogodaDlaMiasta {
+
+	public static void main(String[] args) {
+		try {
+			@SuppressWarnings("resource")
+			Scanner sc = new Scanner(System.in);
+			
+			System.out.print("Podaj nazwę miasta: ");
+			String miasto = sc.nextLine();
+			
+			int idLokalizacji = dajIdLokalizacji(miasto);
+			System.out.println("Znalezione id lokalizacji: " + idLokalizacji);
+			
+			wypiszPogodeDlaLokalizacji(idLokalizacji);
+			
+			
+		} catch (Exception e) {
+			e.printStackTrace();
+		}
+
+	}
+
+	private static JsonArray pobierzJSONArray(String adres) throws IOException {
+		URL url = new URL(adres);
+		try (InputStream in = url.openStream()) {
+			JsonReader reader = Json.createReader(in);
+			return reader.readArray();
+		}
+	}
+	
+	private static JsonObject pobierzJSONObject(String adres) throws IOException {
+		URL url = new URL(adres);
+		try (InputStream in = url.openStream()) {
+			JsonReader reader = Json.createReader(in);
+			return reader.readObject();
+		}
+	}
+
+	private static int dajIdLokalizacji(String miasto) throws IOException {
+		String adres = "https://www.metaweather.com/api/location/search/?query=" + miasto;
+		JsonArray dane = pobierzJSONArray(adres);
+		JsonObject object = dane.getJsonObject(0);
+		return object.getInt("woeid");
+	}
+	
+	private static void wypiszPogodeDlaLokalizacji(int idLokalizacji) throws IOException {
+		String adres = "https://www.metaweather.com/api/location/" + idLokalizacji;
+		JsonObject jsonObject = pobierzJSONObject(adres);
+		JsonArray jsonArray = jsonObject.getJsonArray("consolidated_weather");
+		
+		for (JsonValue jsonValue : jsonArray) {
+			if(jsonValue instanceof JsonObject) {
+				JsonObject prognoza = (JsonObject) jsonValue;
+				System.out.println("Data: " + prognoza.getString("applicable_date"));
+				System.out.println("Ogólny stan: " + prognoza.getString("weather_state_name"));
+				System.out.println("Temperatura: " + prognoza.getJsonNumber("the_temp").doubleValue());
+				
+			}
+			System.out.println();
+		}
+	}
+
+}

src/test/java/waluty/wersja_json/ObslugaNBP.java

+package waluty.wersja_json;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.math.BigDecimal;
+import java.net.URL;
+import java.time.LocalDate;
+
+import javax.json.Json;
+import javax.json.JsonArray;
+import javax.json.JsonObject;
+import javax.json.JsonReader;
+import javax.json.JsonValue;
+
+public class ObslugaNBP {
+	private static final String ADRES = "http://api.nbp.pl/api/exchangerates/tables";
+
+	/**
+	 * Pobiera tabelę z bieżącymi kursami walut. Zwraca null w przypadku błędów.
+	 */
+	public static Tabela pobierzBiezaceKursy() {
+		return wczytajZAdresu(ADRES + "/A?format=json");
+	}
+
+	public static Tabela pobierzKursyHistoryczne(String data) {
+		return wczytajZAdresu(ADRES + "/A/" + data + "?format=json");
+	}
+
+	private static Tabela wczytajZAdresu(String adres) {
+		try {
+			URL url = new URL(adres);
+			try (InputStream in = url.openStream()) {
+				JsonReader reader = Json.createReader(in);
+				JsonArray array = reader.readArray();
+				JsonObject jo_tabela = array.getJsonObject(0);
+
+				String nazwaTabeli = jo_tabela.getString("table");
+				String numerTabeli = jo_tabela.getString("no");
+				LocalDate data = LocalDate.parse(jo_tabela.getString("effectiveDate"));
+
+				Tabela tabela = new Tabela(nazwaTabeli, numerTabeli, data);
+				JsonArray rates = jo_tabela.getJsonArray("rates");
+				for (JsonValue jsonValue : rates) {
+					JsonObject walutaJSON = (JsonObject) jsonValue;
+					String kod = walutaJSON.getString("code");
+					String nazwa = walutaJSON.getString("currency");
+					BigDecimal kurs = walutaJSON.getJsonNumber("mid").bigDecimalValue();
+					Waluta waluta = new Waluta(kod, nazwa, kurs);
+					tabela.dodaj(waluta);
+				}
+				return tabela;
+			}
+		} catch (IOException e) {
+			e.printStackTrace();
+			return null;
+		}
+
+	}
+
+}

src/test/java/waluty/wersja_json/ProbaPobraniaJsona.java

+package waluty.wersja_json;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.math.BigDecimal;
+import java.net.URL;
+
+import javax.json.Json;
+import javax.json.JsonArray;
+import javax.json.JsonObject;
+import javax.json.JsonReader;
+import javax.json.JsonValue;
+
+public class ProbaPobraniaJsona {
+	private static final String ADRES = "http://api.nbp.pl/api/exchangerates/tables";
+
+	public static void main(String[] args) {
+		try {
+			String adres = ADRES + "/A?format=json";
+			URL url = new URL(adres);
+			try (InputStream in = url.openStream()) {
+				System.out.println("zaczynam parsować...");
+				JsonReader reader = Json.createReader(in);
+				JsonArray dane = reader.readArray();
+				//System.out.println(dane);
+
+				JsonObject tabela = dane.getJsonObject(0);
+//				System.out.println(tabela);
+				
+				String numerTabeli = tabela.getString("no");
+				String data = tabela.getString("effectiveDate");
+				System.out.println("Tabela numer " + numerTabeli + " z dnia " + data);
+				
+				JsonArray waluty = tabela.getJsonArray("rates");
+				
+				for (JsonValue jsonValue : waluty) {
+					// jeśli element tablicy jest JSON-owym obiektem (a powinien być), to rzutujemy i odczytujemy pola
+					if(jsonValue instanceof JsonObject) {
+						JsonObject walutaJSON = (JsonObject) jsonValue;
+						String kod = walutaJSON.getString("code");
+						String nazwa = walutaJSON.getString("currency");
+						BigDecimal kurs = walutaJSON.getJsonNumber("mid").bigDecimalValue();
+						Waluta waluta = new Waluta(kod, nazwa, kurs);
+						
+						System.out.println(waluta);
+					}
+				}
+			}
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+
+	}
+
+}

src/test/java/waluty/wersja_json/ProbaPobraniaJsona2.java

+package waluty.wersja_json;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.math.BigDecimal;
+import java.net.MalformedURLException;
+import java.net.URL;
+
+import javax.json.Json;
+import javax.json.JsonArray;
+import javax.json.JsonObject;
+import javax.json.JsonReader;
+import javax.json.JsonValue;
+
+public class ProbaPobraniaJsona2 {
+	private static final String ADRES = "http://api.nbp.pl/api/exchangerates/tables";
+
+	public static void main(String[] args) {
+		try {
+			JsonArray dane = pobierzJSON(ADRES + "/A?format=json");
+				
+			JsonObject tabela = dane.getJsonObject(0);
+			
+			String numerTabeli = tabela.getString("no");
+			String data = tabela.getString("effectiveDate");
+			System.out.println("Tabela numer " + numerTabeli + " z dnia " + data);
+			
+			JsonArray waluty = tabela.getJsonArray("rates");
+			
+			for (JsonValue jsonValue : waluty) {
+				// jeśli element tablicy jest JSON-owym obiektem (a powinien być), to rzutujemy i odczytujemy pola
+				if(jsonValue instanceof JsonObject) {
+					JsonObject walutaJSON = (JsonObject) jsonValue;
+					String kod = walutaJSON.getString("code");
+					String nazwa = walutaJSON.getString("currency");
+					BigDecimal kurs = walutaJSON.getJsonNumber("mid").bigDecimalValue();
+					Waluta waluta = new Waluta(kod, nazwa, kurs);
+					
+					System.out.println(waluta);
+				}
+			}
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+	}
+
+	private static JsonArray pobierzJSON(String adres) throws IOException {
+		URL url = new URL(adres);
+		try (InputStream in = url.openStream()) {
+			JsonReader reader = Json.createReader(in);
+			return reader.readArray();
+		}
+	}
+
+}

src/test/java/waluty/wersja_json/PrzelicznikWalutKonsola.java

+package waluty.wersja_json;
+import java.math.BigDecimal;
+import java.util.Scanner;
+
+public class PrzelicznikWalutKonsola {
+
+	public static void main(String[] args) {
+		System.out.println("Pobieram aktualne kursy...");
+		Tabela tabela = ObslugaNBP.pobierzBiezaceKursy();
+		System.out.println(tabela);
+		
+		try (Scanner sc = new Scanner(System.in)) {
+			while(true) {
+				System.out.println("\nPodaj kod waluty");
+				String kod = sc.nextLine().trim().toUpperCase();
+				if(kod == null || kod.isEmpty())
+					break;
+				
+				Waluta waluta = tabela.znajdz(kod);
+				if(waluta == null) {
+					System.out.println("Nie ma takiej waluty.");
+					continue;
+				}
+				
+				System.out.println("Wybrana waluta: " + waluta.getNazwa());
+				System.out.println("Podaj kwotę");
+				if(!sc.hasNextBigDecimal()) {
+					System.out.println("Nieprawidłowa kwota.");
+					continue;
+				}
+				BigDecimal kwota = sc.nextBigDecimal();
+				sc.nextLine();
+				
+				System.out.println(kwota + " " + kod + " = "
+						+ waluta.przeliczNaZlote(kwota) + " PLN");
+				
+				System.out.println(kwota + " PLN " + " = "
+						+ waluta.przeliczNaWalute(kwota) + " " + kod);
+			}
+		}
+	}
+}

src/test/java/waluty/wersja_json/PrzelicznikWalutOkno.java

+package waluty.wersja_json;
+
+import java.awt.Color;
+import java.awt.EventQueue;
+import java.awt.Font;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+import java.math.BigDecimal;
+import java.time.LocalDate;
+
+import javax.swing.ButtonGroup;
+import javax.swing.DefaultComboBoxModel;
+import javax.swing.GroupLayout;
+import javax.swing.GroupLayout.Alignment;
+import javax.swing.JButton;
+import javax.swing.JComboBox;
+import javax.swing.JFrame;
+import javax.swing.JLabel;
+import javax.swing.JPanel;
+import javax.swing.JRadioButton;
+import javax.swing.JTextField;
+import javax.swing.LayoutStyle.ComponentPlacement;
+import javax.swing.SwingConstants;
+import javax.swing.SwingUtilities;
+import javax.swing.SwingWorker;
+
+public class PrzelicznikWalutOkno {
+	
+	private static final Font FONT_LABEL = new Font("Times New Roman", Font.PLAIN, 24);
+	private static final Font FONT_WARTOSC = new Font("Dialog", Font.BOLD, 24);
+	private static final Font FONT_TXT = new Font("Dialog", Font.BOLD, 32);
+	private static final Font FONT_WYNIK = new Font("Dialog", Font.BOLD, 32);	
+	private static final Font FONT_BUTTON = new Font("Dialog", Font.BOLD, 28);
+
+	private Tabela tabela = null;
+	private JFrame frmPrzelicznikWalut;
+	private JTextField txtKwota;
+	private JComboBox<String> comboBox_Waluta;
+	private JLabel lbl_KodWaluty;
+	private JLabel lbl_NazwaWaluty;
+	private JLabel lbl_KursWaluty;
+	private JRadioButton rdbtnWalutaNaZlote;
+	private JRadioButton rdbtnZloteNaWalute;
+	private JButton btnPrzelicz;
+	private JLabel lblPrawdziwyWynik;
+	private final ButtonGroup buttonGroup = new ButtonGroup();
+	private JPanel panel_1;
+	private JLabel lblTabela;
+	private JLabel lbl_NumerTabeli;
+	private JLabel lblData;
+	private JLabel lbl_DataTabeli;
+	private JTextField txtData;
+	private JButton btnPobierzAktualne;
+
+	/**
+	 * Launch the application.
+	 */
+	public static void main(String[] args) {
+		EventQueue.invokeLater(new Runnable() {
+			public void run() {
+				try {
+					PrzelicznikWalutOkno window = new PrzelicznikWalutOkno();
+					window.txtData.setText(LocalDate.now().toString());
+					window.frmPrzelicznikWalut.setVisible(true);
+					window.pobierzAktualneKursy();
+				} catch (Exception e) {
+					e.printStackTrace();
+				}
+			}
+		});
+	}
+
+	/**
+	 * Create the application.
+	 */
+	public PrzelicznikWalutOkno() {
+		initialize();
+	}
+
+	/**
+	 * Initialize the contents of the frame.
+	 */
+	private void initialize() {
+		frmPrzelicznikWalut = new JFrame();
+		frmPrzelicznikWalut.setTitle("Przelicznik Walut");
+		frmPrzelicznikWalut.setBounds(100, 100, 480, 701);
+		frmPrzelicznikWalut.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+		
+		JLabel lblWybierzWalut = new JLabel("Wybierz walutę");
+		lblWybierzWalut.setFont(FONT_LABEL);
+		
+		comboBox_Waluta = new JComboBox<>();
+		comboBox_Waluta.addActionListener(new ActionListener() {
+			public void actionPerformed(ActionEvent ev) {
+				wyswietlDaneWaluty();
+			}
+		});
+		comboBox_Waluta.setModel(
+				new DefaultComboBoxModel<>(new String[] {"--"}));
+		
+		comboBox_Waluta.setFont(FONT_WARTOSC);
+		
+		JPanel panel = new JPanel();
+		
+		txtKwota = new JTextField();
+		txtKwota.addActionListener(new ActionListener() {
+			public void actionPerformed(ActionEvent ev) {
+				przelicz();
+			}
+		});
+		txtKwota.setText("100");
+		txtKwota.setColumns(10);
+		txtKwota.setFont(FONT_TXT);
+		
+		JLabel lblPodajKwot = new JLabel("Podaj kwotę");
+		lblPodajKwot.setFont(FONT_LABEL);
+		
+		rdbtnWalutaNaZlote = new JRadioButton("waluta na złote");
+		rdbtnWalutaNaZlote.addActionListener(new ActionListener() {
+			public void actionPerformed(ActionEvent ev) {
+				przelicz();
+			}
+		});
+		rdbtnWalutaNaZlote.setFont(FONT_LABEL);
+		
+		buttonGroup.add(rdbtnWalutaNaZlote);
+		
+		rdbtnZloteNaWalute = new JRadioButton("złote na walute");
+		rdbtnZloteNaWalute.setFont(FONT_LABEL);
+		rdbtnZloteNaWalute.addActionListener(new ActionListener() {
+			public void actionPerformed(ActionEvent ev) {
+				przelicz();
+			}
+		});
+		buttonGroup.add(rdbtnZloteNaWalute);
+		
+		btnPrzelicz = new JButton("Przelicz");
+		btnPrzelicz.addActionListener(new ActionListener() {
+			public void actionPerformed(ActionEvent ev) {
+				przelicz();
+			}
+		});
+		btnPrzelicz.setFont(FONT_BUTTON);
+		
+		JLabel lblWynik = new JLabel("Wynik");
+		lblWynik.setFont(FONT_LABEL);
+		
+		lblPrawdziwyWynik = new JLabel("0.00");
+		lblPrawdziwyWynik.setFont(FONT_WYNIK);
+		lblPrawdziwyWynik.setForeground(Color.GRAY);
+		
+		panel_1 = new JPanel();
+		
+		JLabel lblPodajDat = new JLabel("Podaj datę");
+		lblPodajDat.setFont(FONT_LABEL);
+		
+		txtData = new JTextField();
+		txtData.setHorizontalAlignment(SwingConstants.CENTER);
+		txtData.setFont(new Font("Dialog", Font.PLAIN, 20));
+		txtData.setText("data");
+		txtData.setColumns(10);
+		
+		JButton btnZmieDat = new JButton("Zmień datę");
+		btnZmieDat.addActionListener(new ActionListener() {
+			public void actionPerformed(ActionEvent e) {
+				pobierzKursyDlaDaty();
+			}
+		});
+		btnZmieDat.setFont(new Font("Dialog", Font.BOLD, 18));
+		
+		btnPobierzAktualne = new JButton("Pobierz aktualne");
+		btnPobierzAktualne.addActionListener(new ActionListener() {
+			public void actionPerformed(ActionEvent e) {
+				pobierzAktualneKursy();
+			}
+		});
+		btnPobierzAktualne.setFont(new Font("Dialog", Font.BOLD, 18));
+		
+		GroupLayout groupLayout = new GroupLayout(frmPrzelicznikWalut.getContentPane());
+		groupLayout.setHorizontalGroup(
+			groupLayout.createParallelGroup(Alignment.LEADING)
+				.addGroup(groupLayout.createSequentialGroup()
+					.addContainerGap()
+					.addGroup(groupLayout.createParallelGroup(Alignment.TRAILING)
+						.addComponent(panel_1, Alignment.LEADING, GroupLayout.DEFAULT_SIZE, 448, Short.MAX_VALUE)
+						.addComponent(btnPrzelicz, Alignment.LEADING, GroupLayout.DEFAULT_SIZE, 448, Short.MAX_VALUE)
+						.addGroup(Alignment.LEADING, groupLayout.createSequentialGroup()
+							.addComponent(rdbtnWalutaNaZlote)
+							.addPreferredGap(ComponentPlacement.RELATED, 108, Short.MAX_VALUE)
+							.addComponent(rdbtnZloteNaWalute))
+						.addGroup(Alignment.LEADING, groupLayout.createSequentialGroup()
+							.addComponent(lblPodajKwot)
+							.addPreferredGap(ComponentPlacement.RELATED, 139, Short.MAX_VALUE)
+							.addComponent(txtKwota, GroupLayout.PREFERRED_SIZE, 189, GroupLayout.PREFERRED_SIZE))
+						.addComponent(panel, Alignment.LEADING, GroupLayout.DEFAULT_SIZE, 448, Short.MAX_VALUE)
+						.addComponent(lblWynik, Alignment.LEADING)
+						.addComponent(lblPrawdziwyWynik, Alignment.LEADING)
+						.addGroup(Alignment.LEADING, groupLayout.createSequentialGroup()
+							.addGroup(groupLayout.createParallelGroup(Alignment.TRAILING, false)
+								.addComponent(lblPodajDat, Alignment.LEADING, GroupLayout.DEFAULT_SIZE, GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
+								.addComponent(lblWybierzWalut, Alignment.LEADING, GroupLayout.DEFAULT_SIZE, 223, Short.MAX_VALUE))
+							.addPreferredGap(ComponentPlacement.UNRELATED)
+							.addGroup(groupLayout.createParallelGroup(Alignment.LEADING)
+								.addComponent(txtData, GroupLayout.DEFAULT_SIZE, 207, Short.MAX_VALUE)
+								.addComponent(comboBox_Waluta, 0, 207, Short.MAX_VALUE)))
+						.addGroup(groupLayout.createSequentialGroup()
+							.addComponent(btnPobierzAktualne, GroupLayout.PREFERRED_SIZE, 207, GroupLayout.PREFERRED_SIZE)
+							.addGap(34)
+							.addComponent(btnZmieDat, GroupLayout.DEFAULT_SIZE, 207, Short.MAX_VALUE)))
+					.addContainerGap())
+		);
+		groupLayout.setVerticalGroup(
+			groupLayout.createParallelGroup(Alignment.TRAILING)
+				.addGroup(groupLayout.createSequentialGroup()
+					.addContainerGap()
+					.addComponent(panel_1, GroupLayout.PREFERRED_SIZE, 103, GroupLayout.PREFERRED_SIZE)
+					.addPreferredGap(ComponentPlacement.UNRELATED)
+					.addGroup(groupLayout.createParallelGroup(Alignment.LEADING, false)
+						.addComponent(txtData, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
+						.addComponent(lblPodajDat, GroupLayout.DEFAULT_SIZE, GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
+					.addPreferredGap(ComponentPlacement.RELATED)
+					.addGroup(groupLayout.createParallelGroup(Alignment.LEADING)
+						.addComponent(btnZmieDat)
+						.addComponent(btnPobierzAktualne, GroupLayout.PREFERRED_SIZE, 32, GroupLayout.PREFERRED_SIZE))
+					.addPreferredGap(ComponentPlacement.RELATED, 17, Short.MAX_VALUE)
+					.addGroup(groupLayout.createParallelGroup(Alignment.BASELINE)
+						.addComponent(comboBox_Waluta, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
+						.addComponent(lblWybierzWalut))
+					.addPreferredGap(ComponentPlacement.UNRELATED)
+					.addComponent(panel, GroupLayout.PREFERRED_SIZE, 142, GroupLayout.PREFERRED_SIZE)
+					.addPreferredGap(ComponentPlacement.UNRELATED)
+					.addGroup(groupLayout.createParallelGroup(Alignment.BASELINE)
+						.addComponent(txtKwota, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
+						.addComponent(lblPodajKwot))
+					.addPreferredGap(ComponentPlacement.UNRELATED)
+					.addGroup(groupLayout.createParallelGroup(Alignment.BASELINE)
+						.addComponent(rdbtnWalutaNaZlote)
+						.addComponent(rdbtnZloteNaWalute))
+					.addPreferredGap(ComponentPlacement.RELATED)
+					.addComponent(btnPrzelicz)
+					.addPreferredGap(ComponentPlacement.UNRELATED)
+					.addComponent(lblWynik)
+					.addPreferredGap(ComponentPlacement.UNRELATED)
+					.addComponent(lblPrawdziwyWynik)
+					.addGap(33))
+		);
+		
+		lblTabela = new JLabel("Tabela");
+		lblTabela.setFont(FONT_LABEL);
+		
+		lbl_NumerTabeli = new JLabel("?");
+		lbl_NumerTabeli.setFont(new Font("Dialog", Font.BOLD, 24));
+		
+		lblData = new JLabel("Data:");
+		lblData.setFont(FONT_LABEL);
+		
+		lbl_DataTabeli = new JLabel("?");
+		lbl_DataTabeli.setFont(new Font("Dialog", Font.BOLD, 24));
+		
+		GroupLayout gl_panel_1 = new GroupLayout(panel_1);
+		gl_panel_1.setHorizontalGroup(
+			gl_panel_1.createParallelGroup(Alignment.LEADING)
+				.addGroup(gl_panel_1.createSequentialGroup()
+					.addContainerGap()
+					.addGroup(gl_panel_1.createParallelGroup(Alignment.LEADING)
+						.addGroup(gl_panel_1.createSequentialGroup()
+							.addComponent(lblTabela, GroupLayout.PREFERRED_SIZE, 95, GroupLayout.PREFERRED_SIZE)
+							.addGap(18)
+							.addComponent(lbl_NumerTabeli, GroupLayout.PREFERRED_SIZE, 311, GroupLayout.PREFERRED_SIZE))
+						.addGroup(gl_panel_1.createSequentialGroup()
+							.addComponent(lblData, GroupLayout.PREFERRED_SIZE, 95, GroupLayout.PREFERRED_SIZE)
+							.addGap(18)
+							.addComponent(lbl_DataTabeli, GroupLayout.PREFERRED_SIZE, 311, GroupLayout.PREFERRED_SIZE)))
+					.addContainerGap(GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
+		);
+		gl_panel_1.setVerticalGroup(
+			gl_panel_1.createParallelGroup(Alignment.LEADING)
+				.addGroup(gl_panel_1.createSequentialGroup()
+					.addContainerGap()
+					.addGroup(gl_panel_1.createParallelGroup(Alignment.LEADING)
+						.addComponent(lblTabela, GroupLayout.PREFERRED_SIZE, 29, GroupLayout.PREFERRED_SIZE)
+						.addComponent(lbl_NumerTabeli, GroupLayout.PREFERRED_SIZE, 29, GroupLayout.PREFERRED_SIZE))
+					.addGap(12)
+					.addGroup(gl_panel_1.createParallelGroup(Alignment.LEADING)
+						.addComponent(lblData, GroupLayout.PREFERRED_SIZE, 29, GroupLayout.PREFERRED_SIZE)
+						.addComponent(lbl_DataTabeli, GroupLayout.PREFERRED_SIZE, 29, GroupLayout.PREFERRED_SIZE))
+					.addContainerGap(21, Short.MAX_VALUE))
+		);
+		panel_1.setLayout(gl_panel_1);
+		
+		JLabel lblKod = new JLabel("Kod:");
+		lblKod.setFont(FONT_LABEL);
+		
+		JLabel lblNazwa = new JLabel("Nazwa:");
+		lblNazwa.setFont(FONT_LABEL);
+		
+		JLabel lblKurs = new JLabel("Kurs:");
+		lblKurs.setFont(FONT_LABEL);
+		
+		lbl_KodWaluty = new JLabel("kod");
+		lbl_KodWaluty.setFont(FONT_WARTOSC);
+		
+		lbl_NazwaWaluty = new JLabel("nazwa");
+		lbl_NazwaWaluty.setFont(FONT_WARTOSC);
+		
+		lbl_KursWaluty = new JLabel("1.0000");
+		lbl_KursWaluty.setFont(FONT_WARTOSC);
+
+		GroupLayout gl_panel = new GroupLayout(panel);
+		gl_panel.setHorizontalGroup(
+			gl_panel.createParallelGroup(Alignment.LEADING)
+				.addGroup(gl_panel.createSequentialGroup()
+					.addContainerGap()
+					.addGroup(gl_panel.createParallelGroup(Alignment.LEADING, false)
+						.addComponent(lblKurs, Alignment.TRAILING, GroupLayout.DEFAULT_SIZE, GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
+						.addComponent(lblNazwa, Alignment.TRAILING, GroupLayout.DEFAULT_SIZE, GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
+						.addComponent(lblKod, Alignment.TRAILING, GroupLayout.DEFAULT_SIZE, 95, Short.MAX_VALUE))
+					.addPreferredGap(ComponentPlacement.RELATED, 18, GroupLayout.PREFERRED_SIZE)
+					.addGroup(gl_panel.createParallelGroup(Alignment.LEADING)
+						.addComponent(lbl_KodWaluty, Alignment.TRAILING, GroupLayout.DEFAULT_SIZE, 171, Short.MAX_VALUE)
+						.addComponent(lbl_NazwaWaluty, Alignment.TRAILING, GroupLayout.DEFAULT_SIZE, 171, Short.MAX_VALUE)
+						.addComponent(lbl_KursWaluty, Alignment.TRAILING, GroupLayout.DEFAULT_SIZE, 171, Short.MAX_VALUE))
+					.addContainerGap())
+		);
+		gl_panel.setVerticalGroup(
+			gl_panel.createParallelGroup(Alignment.LEADING)
+				.addGroup(gl_panel.createSequentialGroup()
+					.addContainerGap()
+					.addGroup(gl_panel.createParallelGroup(Alignment.BASELINE)
+						.addComponent(lblKod)
+						.addComponent(lbl_KodWaluty))
+					.addPreferredGap(ComponentPlacement.UNRELATED)
+					.addGroup(gl_panel.createParallelGroup(Alignment.BASELINE)
+						.addComponent(lblNazwa)
+						.addComponent(lbl_NazwaWaluty))
+					.addPreferredGap(ComponentPlacement.UNRELATED)
+					.addGroup(gl_panel.createParallelGroup(Alignment.BASELINE)
+						.addComponent(lblKurs)
+						.addComponent(lbl_KursWaluty))
+					.addContainerGap(61, Short.MAX_VALUE))
+		);
+		panel.setLayout(gl_panel);
+		frmPrzelicznikWalut.getContentPane().setLayout(groupLayout);
+	}
+	
+	protected void przelicz() {
+		try {
+			BigDecimal kwota = new BigDecimal(txtKwota.getText());
+			String kod = "" + comboBox_Waluta.getSelectedItem();
+			Waluta waluta = tabela.znajdz(kod);
+			BigDecimal wynik = null;
+			if(rdbtnWalutaNaZlote.isSelected()) {
+				wynik = waluta.przeliczNaZlote(kwota);
+			}
+			if(rdbtnZloteNaWalute.isSelected()) {
+				wynik = waluta.przeliczNaWalute(kwota);
+			}
+			lblPrawdziwyWynik.setText("" + wynik);
+			lblPrawdziwyWynik.setForeground(Color.BLUE);
+		} catch (Exception e) {
+			lblPrawdziwyWynik.setText("błąd");
+			lblPrawdziwyWynik.setForeground(Color.RED);
+		}		
+	}
+
+	protected void wyswietlDaneWaluty() {
+		String kod = "" + comboBox_Waluta.getSelectedItem();
+		Waluta waluta = tabela.znajdz(kod);
+		if(waluta != null) {
+			lbl_KodWaluty.setText(waluta.getKod());
+			lbl_NazwaWaluty.setText(waluta.getNazwa());
+			lbl_KursWaluty.setText("" + waluta.getKurs());
+			if(! txtKwota.getText().isEmpty()) {
+				przelicz();
+			}
+			return;
+		}
+		lblPrawdziwyWynik.setText("0.00");
+		lblPrawdziwyWynik.setForeground(Color.GRAY);
+	}
+
+	private void pobierzAktualneKursy() {
+		// Pobieranie aktualnych kursów w tle (to znaczy w innym wątku)
+		// Aby wykonać operację w tle, w Swingu najlepiej użyć klasy SwingWorker
+		
+		SwingWorker<Void, Void> worker = new SwingWorker<Void, Void>() {
+			protected Void doInBackground() {
+				tabela = ObslugaNBP.pobierzBiezaceKursy();
+				return null;
+			}
+			
+			protected void done() {
+				// tu piszemy "co ma zrobić okno, gdy operacja jest zakończona"
+				// to będzie wykonane przez wątek EDT
+				odswiezDaneTabeli();
+				wyswietlDaneWaluty();
+			}
+		};
+		
+		worker.execute();
+	}
+
+	private void pobierzKursyDlaDaty() {
+		SwingWorker<Void, Void> worker = new SwingWorker<Void, Void>() {
+			protected Void doInBackground() throws Exception {
+				
+				String data = txtData.getText();
+				Tabela nowaTabela = ObslugaNBP.pobierzKursyHistoryczne(data);
+				if(nowaTabela != null) {
+					tabela = nowaTabela;
+					SwingUtilities.invokeLater(() -> {
+						txtData.setForeground(Color.BLACK);
+					});
+				} else {
+					SwingUtilities.invokeLater(() -> {
+						txtData.setForeground(Color.RED);
+					});
+				}
+				return null;
+			}
+			
+			protected void done() {
+				odswiezDaneTabeli();
+				wyswietlDaneWaluty();
+			}
+		};
+		
+		worker.execute();
+	}
+
+	private void odswiezDaneTabeli() {
+		lbl_NumerTabeli.setText(tabela.getNumerTabeli());
+		lbl_DataTabeli.setText("" + tabela.getData());
+		comboBox_Waluta.setModel(new DefaultComboBoxModel<>(tabela.getKodyWalut()));
+	}
+}
\ No newline at end of file

src/test/java/waluty/wersja_json/Tabela.java

+package waluty.wersja_json;
+
+import java.time.LocalDate;
+import java.util.Collection;
+import java.util.Map;
+import java.util.Objects;
+import java.util.TreeMap;
+
+public class Tabela {
+	private final String nazwaTabeli;
+	private final String numerTabeli;
+	private final LocalDate data;
+	private final Map<String, Waluta> waluty = new TreeMap<>();
+	
+	public Tabela() {
+		nazwaTabeli = null;
+		numerTabeli = null;
+		data = null;
+	}
+
+	public Tabela(String nazwaTabeli, String numerTabeli, LocalDate data) {
+		this.nazwaTabeli = nazwaTabeli;
+		this.numerTabeli = numerTabeli;
+		this.data = data;
+	}
+
+	public String getNazwaTabeli() {
+		return nazwaTabeli;
+	}
+
+	public String getNumerTabeli() {
+		return numerTabeli;
+	}
+
+	public LocalDate getData() {
+		return data;
+	}
+
+	@Override
+	public String toString() {
+		return "Tabela " + nazwaTabeli + " nr " + numerTabeli
+				+ " z dnia " + data + " (" + waluty.size() + " walut)";
+	}
+	
+	public void dodaj(Waluta waluta) {
+		waluty.put(waluta.getKod(), waluta);
+	}
+	
+	public Waluta znajdz(String kod) {
+		return waluty.get(kod);
+	}
+	
+	public Collection<Waluta> getWszystkieWaluty() {
+		return waluty.values();
+	}
+	
+	private static final String[] PUSTA_TABLICA = new String[0];
+	
+	public String[] getKodyWalut() {
+		return waluty.keySet().toArray(PUSTA_TABLICA);
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(data, nazwaTabeli, numerTabeli, waluty);
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		Tabela other = (Tabela) obj;
+		return Objects.equals(data, other.data) && Objects.equals(nazwaTabeli, other.nazwaTabeli)
+				&& Objects.equals(numerTabeli, other.numerTabeli) && Objects.equals(waluty, other.waluty);
+	}
+
+	
+}

src/test/java/waluty/wersja_json/Waluta.java

+package waluty.wersja_json;
+
+import java.math.BigDecimal;
+import java.math.RoundingMode;
+import java.util.Objects;
+
+public class Waluta {
+    private final String kod;
+    private final String nazwa;
+    private final BigDecimal kurs;
+    
+	public Waluta(String kod, String nazwa, BigDecimal kurs) {
+		this.kod = kod;
+		this.nazwa = nazwa;
+		this.kurs = kurs;
+	}
+
+	public String getKod() {
+		return kod;
+	}
+
+	public String getNazwa() {
+		return nazwa;
+	}
+
+	public BigDecimal getKurs() {
+		return kurs;
+	}
+    
+    @Override
+    public String toString() {
+        return nazwa + " (" + kod + "): " + kurs;
+    }
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(kod, kurs, nazwa);
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		Waluta other = (Waluta) obj;
+		return Objects.equals(kod, other.kod) && Objects.equals(kurs, other.kurs) && Objects.equals(nazwa, other.nazwa);
+	}
+	
+	public BigDecimal przeliczNaZlote(BigDecimal kwota) {
+		return kwota.multiply(kurs).setScale(2, RoundingMode.HALF_UP);
+	}
+
+	public BigDecimal przeliczNaWalute(BigDecimal kwota) {
+		return kwota.divide(kurs, 2, RoundingMode.HALF_UP);
+	}
+    
+}

src/test/java/waluty/wersja_json/WypiszWszystkieWaluty.java

+package waluty.wersja_json;
+import java.util.Collection;
+
+public class WypiszWszystkieWaluty {
+
+	public static void main(String[] args) {
+		Tabela tabela = ObslugaNBP.pobierzBiezaceKursy();		
+		System.out.println("Pobrana tabela: " + tabela);
+		
+		Collection<Waluta> waluty = tabela.getWszystkieWaluty();
+		for (Waluta waluta : waluty) {
+			System.out.println(waluta);
+		}
+	}
+
+}