dom parsing

xml/src/test/java/com/baeldung/xml/XercesDomUnitTest.java

@@ -0,0 +1,139 @@
+package com.baeldung.xml;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.File;
+
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.transform.Transformer;
+import javax.xml.transform.TransformerFactory;
+import javax.xml.transform.dom.DOMSource;
+import javax.xml.transform.stream.StreamResult;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+import org.w3c.dom.NamedNodeMap;
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
+
+public class XercesDomUnitTest {
+
+    final private String FILE_NAME = "src/test/resources/example_jdom.xml";
+    final private String OUTPUT_DOM = "src/test/resources/Xerces_dom.xml";
+
+    private Document doc;
+    private DocumentBuilder builder;
+
+    @Before
+    public void loadXmlFile() throws Exception {
+        if (doc == null) {
+            builder = DocumentBuilderFactory.newInstance()
+                .newDocumentBuilder();
+            doc = builder.parse(new File(FILE_NAME));
+            doc.getDocumentElement()
+                .normalize();
+        }
+    }
+
+    @Test
+    public void whenGetElementByTag_thenSuccess() {
+        NodeList nodeList = doc.getElementsByTagName("tutorial");
+        Node first = nodeList.item(0);
+
+        assertEquals(4, nodeList.getLength());
+        assertEquals(Node.ELEMENT_NODE, first.getNodeType());
+        assertEquals("tutorial", first.getNodeName());        
+    }
+
+    @Test
+    public void whenGetFirstElementAttributes_thenSuccess() {
+        Node first = doc.getElementsByTagName("tutorial")
+            .item(0);
+        NamedNodeMap attrList = first.getAttributes();
+
+        assertEquals(2, attrList.getLength());
+        
+        assertEquals("tutId", attrList.item(0)
+            .getNodeName());
+        assertEquals("01", attrList.item(0)
+            .getNodeValue());
+        
+        assertEquals("type", attrList.item(1)
+            .getNodeName());
+        assertEquals("java", attrList.item(1)
+            .getNodeValue());
+    }
+
+    
+    @Test
+    public void whenTraverseChildNodes_thenSuccess() {
+        Node first = doc.getElementsByTagName("tutorial")
+            .item(0);
+        NodeList nodeList = first.getChildNodes();
+        int n = nodeList.getLength();
+
+        Node current;
+        for (int i = 0; i < n; i++) {
+            current = nodeList.item(i);
+            if (current.getNodeType() == Node.ELEMENT_NODE) {
+                System.out.println(current.getNodeName() + ": " + current.getTextContent());
+            }
+        }
+    }
+
+    @Test
+    public void whenModifyElementAttribute_thenModified() {
+        NodeList nodeList = doc.getElementsByTagName("tutorial");
+        Element first = (Element) nodeList.item(0);
+        assertEquals("java", first.getAttribute("type"));
+
+        first.setAttribute("type", "other");
+        assertEquals("other", first.getAttribute("type"));
+    }
+    
+
+    @Test
+    public void whenCreateNewDocument_thenCreated() throws Exception {
+        Document newDoc = builder.newDocument();
+        Element root = newDoc.createElement("users");
+        newDoc.appendChild(root);
+
+        Element first = newDoc.createElement("user");
+        root.appendChild(first);
+        first.setAttribute("id", "1");
+
+        Element email = newDoc.createElement("email");
+        email.appendChild(newDoc.createTextNode("john@example.com"));
+        first.appendChild(email);
+
+        assertEquals(1, newDoc.getChildNodes()
+            .getLength());
+        assertEquals("users", newDoc.getChildNodes()
+            .item(0)
+            .getNodeName());
+
+        printDom(newDoc);
+        saveDomToFile(newDoc, OUTPUT_DOM);
+    }
+
+    private void printDom(Document document) throws Exception {
+        DOMSource dom = new DOMSource(document);
+        Transformer transformer = TransformerFactory.newInstance()
+            .newTransformer();
+
+        transformer.transform(dom, new StreamResult(System.out));
+    }
+
+    private void saveDomToFile(Document document, String fileName) throws Exception {
+        DOMSource dom = new DOMSource(document);
+        Transformer transformer = TransformerFactory.newInstance()
+            .newTransformer();
+
+        StreamResult result = new StreamResult(new File(fileName));
+        transformer.transform(dom, result);
+    }
+
+}

xml/src/test/resources/Xerces_dom.xml

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+<?xml version="1.0" encoding="UTF-8" standalone="no"?><users><user id="1"><email>john@example.com</email></user></users>