Waluty REST

PC25-Spring/src/main/java/com/example/demo/waluty/WalutyRest.java

+package com.example.demo.waluty;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.math.BigDecimal;
+import java.net.URL;
+import java.time.LocalDate;
+
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.xpath.XPath;
+import javax.xml.xpath.XPathConstants;
+import javax.xml.xpath.XPathExpressionException;
+import javax.xml.xpath.XPathFactory;
+
+import org.springframework.ui.Model;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.w3c.dom.Document;
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
+import org.xml.sax.SAXException;
+
+@RestController
+@RequestMapping("/waluty.rest")
+public class WalutyRest {
+    
+    @GetMapping
+    public TabelaWalut wyswietlWaluty() {
+        TabelaWalut tabela = pobierzTabele(null);
+        return tabela;
+    }
+    
+    @GetMapping("/{data}")
+    public TabelaWalut wyswietlWaluty(@PathVariable String data) {
+        TabelaWalut tabela = pobierzTabele(data);
+        return tabela;
+    }
+
+    private TabelaWalut pobierzTabele(String data) {
+        String adres = "https://api.nbp.pl/api/exchangerates/tables/a";
+        if(data != null) {
+            adres += "/" + data;
+        }
+        adres += "?format=xml";
+        try {
+            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
+            DocumentBuilder db = dbf.newDocumentBuilder();
+            Document doc = null;
+            URL url = new URL(adres);
+            try (InputStream in = url.openStream()) {
+                doc = db.parse(in);
+            }
+            
+            XPathFactory xpf = XPathFactory.newInstance();
+            XPath xpath = xpf.newXPath();
+
+            // String numer = xpath.evaluate(
+            // "/ArrayOfExchangeRatesTable/ExchangeRatesTable/No", doc);
+
+            String nazwaTabeli = xpath.evaluate("//Table", doc);
+            String numerTabeli = xpath.evaluate("//No", doc);
+            LocalDate dataTabeli = LocalDate.parse(xpath.evaluate("//EffectiveDate", doc));
+
+            TabelaWalut tabela = new TabelaWalut(nazwaTabeli, numerTabeli, dataTabeli);
+
+            NodeList rates = (NodeList) xpath.evaluate("//Rate", doc, XPathConstants.NODESET);
+            final int n = rates.getLength();
+            for (int i = 0; i < n; i++) {
+                Node rate = rates.item(i);
+                String kod = xpath.evaluate("Code", rate);
+                String nazwa = xpath.evaluate("Currency", rate);
+                BigDecimal kurs = new BigDecimal(xpath.evaluate("Mid", rate));
+                Waluta waluta = new Waluta(kod, nazwa, kurs);
+                tabela.dodajWalute(waluta);
+            }
+
+            return tabela;
+        } catch (ParserConfigurationException | SAXException | XPathExpressionException | IOException e) {
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+}

PC25-Spring/src/main/resources/templates/index.html

@@ -38,6 +38,8 @@
 <ul>
 <li><a th:href="@{/kalkulator}">Kalkulator</a></li>
 <li><a th:href="@{/waluty}">Kursy walut</a></li>
+<li><a th:href="@{/waluty.rest}">Waluty REST</a> - bieżące</li>
+<li><a th:href="@{/waluty.rest/2008-08-08}">Waluty REST</a> - archiwalne</li>
 </ul>
 
 </body>