BAEL 2338 - Sample code for the article (#7762)

* FEAT Added Jaxp transformer to convert xml to html

* CHORE Added additional refactors

* UPDATE Refactor to use Map instead of Element navigation

* FEAT Added Stax transformer to convert from XML to HTML

* FEAT Added Freemarker transformer

* FEAT Added Mustache transformer

xml/pom.xml

@@ -59,6 +59,16 @@
             <artifactId>stax-api</artifactId>
             <version>${stax-api.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.freemarker</groupId>
+            <artifactId>freemarker</artifactId>
+            <version>${freemarker.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.github.spullara.mustache.java</groupId>
+            <artifactId>compiler</artifactId>
+            <version>${mustache.version}</version>
+        </dependency>
         <!-- JMH Libraries -->
         <dependency>
             <groupId>org.openjdk.jmh</groupId>
@@ -324,6 +334,8 @@
         <xmlunit-assertj.version>2.6.3</xmlunit-assertj.version>
         <junit-jupiter.version>5.5.0</junit-jupiter.version>
         <jmh.version>1.21</jmh.version>
+        <freemarker.version>2.3.29</freemarker.version>
+        <mustache.version>0.9.6</mustache.version>
         <!-- util -->
         <commons-lang3.version>3.5</commons-lang3.version>
         <commons-lang.version>2.4</commons-lang.version>

xml/src/main/java/com/baeldung/xmlhtml/freemarker/FreemarkerTransformer.java

@@ -0,0 +1,40 @@
+package com.baeldung.xmlhtml.freemarker;
+
+import com.baeldung.xmlhtml.stax.StaxTransformer;
+import freemarker.template.Configuration;
+import freemarker.template.Template;
+import freemarker.template.TemplateException;
+import freemarker.template.TemplateExceptionHandler;
+
+import javax.xml.stream.XMLStreamException;
+import java.io.File;
+import java.io.IOException;
+import java.io.StringWriter;
+import java.io.Writer;
+import java.nio.charset.StandardCharsets;
+
+public class FreemarkerTransformer {
+    private StaxTransformer staxTransformer;
+    private String templateDirectory;
+    private String templateFile;
+
+    public FreemarkerTransformer(StaxTransformer staxTransformer, String templateDirectory, String templateFile) {
+        this.staxTransformer = staxTransformer;
+        this.templateDirectory = templateDirectory;
+        this.templateFile = templateFile;
+    }
+
+    public String html() throws IOException, XMLStreamException, TemplateException {
+        Configuration cfg = new Configuration(Configuration.VERSION_2_3_29);
+        cfg.setDirectoryForTemplateLoading(new File(templateDirectory));
+        cfg.setDefaultEncoding(StandardCharsets.UTF_8.toString());
+        cfg.setTemplateExceptionHandler(TemplateExceptionHandler.RETHROW_HANDLER);
+        cfg.setLogTemplateExceptions(false);
+        cfg.setWrapUncheckedExceptions(true);
+        cfg.setFallbackOnNullLoopVariable(false);
+        Template temp = cfg.getTemplate(templateFile);
+        Writer output = new StringWriter();
+        temp.process(staxTransformer.buildMap(), output);
+        return output.toString();
+    }
+}

xml/src/main/java/com/baeldung/xmlhtml/helpers/XMLRunner.java

@@ -2,15 +2,11 @@ package com.baeldung.xmlhtml.helpers;
 
 
 import com.baeldung.xmlhtml.helpers.jaxb.JAXBHelper;
-import com.baeldung.xmlhtml.helpers.jaxp.JAXPHelper;
+import com.baeldung.xmlhtml.stax.StaxTransformer;
-import com.baeldung.xmlhtml.helpers.stax.STAXHelper;
 
 public class XMLRunner {
 
     public static void doWork() {
         JAXBHelper.example();
-        JAXPHelper.saxParser();
-        JAXPHelper.documentBuilder();
-        STAXHelper.write(STAXHelper.read());
     }
 }

xml/src/main/java/com/baeldung/xmlhtml/helpers/jaxp/CustomHandler.java

@@ -1,34 +0,0 @@
-package com.baeldung.xmlhtml.helpers.jaxp;
-
-import org.xml.sax.ContentHandler;
-import org.xml.sax.Locator;
-
-import static com.baeldung.xmlhtml.Constants.*;
-
-public class CustomHandler implements ContentHandler {
-
-    public void startDocument() {}
-
-    public void startElement(String uri, String localName, String qName, org.xml.sax.Attributes atts) { }
-
-    public void endDocument() {
-        System.out.println(DOCUMENT_END);
-    }
-
-    public void endElement(String uri, String localName, String qName) { }
-
-    public void startPrefixMapping(String prefix, String uri) { }
-
-    public void endPrefixMapping(String prefix) { }
-
-    public void setDocumentLocator(Locator locator) { }
-
-    public void characters(char[] ch, int start, int length) {  }
-
-    public void ignorableWhitespace(char[] ch, int start, int length) {  }
-
-    public void processingInstruction(String target, String data) {  }
-
-    public void skippedEntity(String name) { }
-
-}

xml/src/main/java/com/baeldung/xmlhtml/helpers/jaxp/JAXPHelper.java

@@ -1,90 +0,0 @@
-package com.baeldung.xmlhtml.helpers.jaxp;
-
-import org.w3c.dom.Document;
-import org.w3c.dom.Element;
-import org.w3c.dom.Node;
-import org.w3c.dom.NodeList;
-import org.xml.sax.XMLReader;
-
-import javax.xml.parsers.DocumentBuilder;
-import javax.xml.parsers.DocumentBuilderFactory;
-import javax.xml.parsers.SAXParser;
-import javax.xml.parsers.SAXParserFactory;
-import javax.xml.transform.TransformerFactory;
-import javax.xml.transform.dom.DOMSource;
-import javax.xml.transform.stream.StreamResult;
-import java.io.File;
-
-import static com.baeldung.xmlhtml.Constants.*;
-
-public class JAXPHelper {
-
-    private static void print(Document document) {
-        NodeList list = document.getChildNodes();
-        try {
-            for (int i = 0; i < list.getLength(); i++) {
-                Node node = list.item(i);
-                String message =
-                        node.getNodeType()
-                                + WHITE_SPACE
-                                + node.getNodeName()
-                                + LINE_BREAK;
-                System.out.println(message);
-            }
-        } catch (Exception ex) {
-            System.out.println(EXCEPTION_ENCOUNTERED + ex);
-        }
-    }
-
-    public static void saxParser() {
-        SAXParserFactory spf = SAXParserFactory.newInstance();
-        spf.setNamespaceAware(true);
-        try {
-            SAXParser saxParser = spf.newSAXParser();
-            XMLReader xmlReader = saxParser.getXMLReader();
-            xmlReader.setContentHandler(new CustomHandler());
-            xmlReader.parse(XML_FILE_IN);
-        } catch (Exception ex) {
-            System.out.println(EXCEPTION_ENCOUNTERED + ex);
-        }
-    }
-
-    public static void documentBuilder() {
-        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
-        try {
-            DocumentBuilder db = dbf.newDocumentBuilder();
-            Document parsed = db.parse(new File(XML_FILE_IN));
-            Element xml = parsed.getDocumentElement();
-
-            Document doc = db.newDocument();
-            Element html = doc.createElement("html");
-            Element head = doc.createElement("head");
-            html.appendChild(head);
-
-            Element body = doc.createElement("body");
-            Element descendantOne = doc.createElement("p");
-            descendantOne.setTextContent("descendantOne: " +
-                    xml.getElementsByTagName("descendantOne")
-                            .item(0).getTextContent());
-            Element descendantThree = doc.createElement("p");
-            descendantThree.setTextContent("descendantThree: " +
-                    xml.getElementsByTagName("descendantThree")
-                            .item(0).getTextContent());
-            Element nested = doc.createElement("div");
-            nested.appendChild(descendantThree);
-
-            body.appendChild(descendantOne);
-            body.appendChild(nested);
-            html.appendChild(body);
-            doc.appendChild(html);
-
-            TransformerFactory tFactory = TransformerFactory.newInstance();
-            tFactory
-                    .newTransformer()
-                    .transform(new DOMSource(doc), new StreamResult(new File(JAXP_FILE_OUT)));
-
-        } catch (Exception ex) {
-            System.out.println(EXCEPTION_ENCOUNTERED + ex);
-        }
-    }
-}

xml/src/main/java/com/baeldung/xmlhtml/helpers/stax/STAXHelper.java

@@ -1,112 +0,0 @@
-package com.baeldung.xmlhtml.helpers.stax;
-
-import com.baeldung.xmlhtml.pojo.stax.Body;
-import com.baeldung.xmlhtml.pojo.stax.CustomElement;
-import com.baeldung.xmlhtml.pojo.stax.NestedElement;
-
-import javax.xml.stream.XMLInputFactory;
-import javax.xml.stream.XMLOutputFactory;
-import javax.xml.stream.XMLStreamReader;
-import javax.xml.stream.XMLStreamWriter;
-import java.io.FileInputStream;
-import java.io.FileWriter;
-
-import static com.baeldung.xmlhtml.Constants.*;
-
-public class STAXHelper {
-
-    private static XMLStreamReader reader() {
-        XMLStreamReader xmlStreamReader = null;
-        try {
-            xmlStreamReader = XMLInputFactory.newInstance().createXMLStreamReader(new FileInputStream(XML_FILE_IN));
-        } catch (Exception ex) {
-            System.out.println(EXCEPTION_ENCOUNTERED + ex);
-        }
-        return xmlStreamReader;
-    }
-
-    private static XMLStreamWriter writer() {
-        XMLStreamWriter xmlStreamWriter = null;
-        try {
-            xmlStreamWriter = XMLOutputFactory.newInstance().createXMLStreamWriter(new FileWriter(STAX_FILE_OUT));
-        } catch (Exception ex) {
-            System.out.println(EXCEPTION_ENCOUNTERED + ex);
-        }
-        return xmlStreamWriter;
-    }
-
-    public static Body read() {
-        Body body = new Body();
-        try {
-            XMLStreamReader xmlStreamReader = reader();
-
-            CustomElement customElement = new CustomElement();
-            NestedElement nestedElement = new NestedElement();
-            CustomElement child = new CustomElement();
-
-            while (xmlStreamReader.hasNext()) {
-                xmlStreamReader.next();
-                if (xmlStreamReader.isStartElement()) {
-                    System.out.println(xmlStreamReader.getLocalName());
-                    if (xmlStreamReader.getLocalName().equals("descendantOne")) {
-                        customElement.setValue(xmlStreamReader.getElementText());
-                    }
-                    if (xmlStreamReader.getLocalName().equals("descendantThree")) {
-                        child.setValue(xmlStreamReader.getElementText());
-                    }
-                }
-            }
-
-            nestedElement.setCustomElement(child);
-            body.setCustomElement(customElement);
-            body.setNestedElement(nestedElement);
-
-            xmlStreamReader.close();
-
-        } catch (Exception ex) {
-            System.out.println(EXCEPTION_ENCOUNTERED + ex);
-        }
-        return body;
-    }
-
-    public static void write(Body body) {
-        try {
-
-            XMLStreamWriter xmlStreamWriter = writer();
-            xmlStreamWriter.writeStartElement("html");
-            xmlStreamWriter.writeCharacters(BREAK + TAB);
-            xmlStreamWriter.writeStartElement("head");
-            xmlStreamWriter.writeCharacters(BREAK + TAB + TAB);
-            xmlStreamWriter.writeStartElement("meta");
-            xmlStreamWriter.writeEndElement();
-            xmlStreamWriter.writeCharacters(BREAK + TAB);
-            xmlStreamWriter.writeEndElement();
-            xmlStreamWriter.writeCharacters(BREAK + TAB);
-            xmlStreamWriter.writeStartElement("body");
-            xmlStreamWriter.writeCharacters(BREAK + TAB + TAB);
-            xmlStreamWriter.writeStartElement("p");
-            xmlStreamWriter.writeCharacters("descendantOne: " + body.getCustomElement().getValue());
-            xmlStreamWriter.writeEndElement();
-            xmlStreamWriter.writeCharacters(BREAK + TAB + TAB);
-            xmlStreamWriter.writeStartElement("div");
-            xmlStreamWriter.writeCharacters(BREAK + TAB + TAB + TAB);
-            xmlStreamWriter.writeStartElement("p");
-            xmlStreamWriter.writeCharacters(BREAK);
-            xmlStreamWriter.writeCharacters(TAB + TAB + TAB + TAB + "descendantThree: " + body.getNestedElement().getCustomElement().getValue());
-            xmlStreamWriter.writeCharacters(BREAK + TAB + TAB + TAB);
-            xmlStreamWriter.writeEndElement();
-            xmlStreamWriter.writeCharacters(BREAK + TAB + TAB);
-            xmlStreamWriter.writeEndElement();
-            xmlStreamWriter.writeCharacters(BREAK + TAB);
-            xmlStreamWriter.writeEndElement();
-            xmlStreamWriter.writeCharacters(BREAK);
-            xmlStreamWriter.writeEndDocument();
-            xmlStreamWriter.flush();
-            xmlStreamWriter.close();
-
-        } catch (Exception ex) {
-            System.out.println(EXCEPTION_ENCOUNTERED + ex);
-        }
-
-    }
-}

xml/src/main/java/com/baeldung/xmlhtml/jaxp/JaxpTransformer.java

@@ -0,0 +1,102 @@
+package com.baeldung.xmlhtml.jaxp;
+
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+import org.xml.sax.SAXException;
+
+import javax.xml.XMLConstants;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.transform.Transformer;
+import javax.xml.transform.TransformerException;
+import javax.xml.transform.TransformerFactory;
+import javax.xml.transform.dom.DOMSource;
+import javax.xml.transform.stream.StreamResult;
+import java.io.IOException;
+import java.io.StringWriter;
+import java.io.Writer;
+import java.util.HashMap;
+import java.util.Map;
+
+public class JaxpTransformer {
+
+    private Document input;
+    private DocumentBuilderFactory factory;
+
+    public JaxpTransformer(String resourcePath) throws ParserConfigurationException, IOException, SAXException {
+        // 1- Build the doc from the XML file
+        factory = DocumentBuilderFactory.newInstance();
+        factory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
+        input = factory
+          .newDocumentBuilder()
+          .parse(resourcePath);
+    }
+
+    public String html() throws ParserConfigurationException, TransformerException {
+        Element xml = input.getDocumentElement();
+        Document doc = factory
+          .newDocumentBuilder()
+          .newDocument();
+        //Build Map
+        Map<String, String> map = buildMap(xml);
+        //Head
+        Element html = doc.createElement("html");
+        html.setAttribute("lang", "en");
+        Element head = buildHead(map, doc);
+        html.appendChild(head);
+        //Body
+        Element body = buildBody(map, doc);
+        html.appendChild(body);
+        doc.appendChild(html);
+        Writer output = applyTransformation(doc);
+        return String.format("<!DOCTYPE html>%n%s", output.toString());
+    }
+
+    private Writer applyTransformation(Document doc) throws TransformerException {
+        TransformerFactory transformerFactory = TransformerFactory.newInstance();
+        transformerFactory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
+        transformerFactory.setAttribute(XMLConstants.ACCESS_EXTERNAL_DTD, "");
+        transformerFactory.setAttribute(XMLConstants.ACCESS_EXTERNAL_STYLESHEET, "");
+        Writer output = new StringWriter();
+        Transformer transformer = transformerFactory.newTransformer();
+        transformer.transform(new DOMSource(doc), new StreamResult(output));
+        return output;
+    }
+
+    private Map<String, String> buildMap(Element xml) {
+        Map<String, String> map = new HashMap<>();
+        map.put("heading", xml
+          .getElementsByTagName("heading")
+          .item(0)
+          .getTextContent());
+        map.put("from", String.format("from: %s", xml
+          .getElementsByTagName("from")
+          .item(0)
+          .getTextContent()));
+        map.put("content", xml
+          .getElementsByTagName("content")
+          .item(0)
+          .getTextContent());
+        return map;
+    }
+
+    private Element buildHead(Map<String, String> map, Document doc) {
+        Element head = doc.createElement("head");
+        Element title = doc.createElement("title");
+        title.setTextContent(map.get("heading"));
+        head.appendChild(title);
+        return head;
+    }
+
+    private Element buildBody(Map<String, String> map, Document doc) {
+        Element body = doc.createElement("body");
+        Element from = doc.createElement("p");
+        from.setTextContent(map.get("from"));
+        Element success = doc.createElement("p");
+        success.setTextContent(map.get("content"));
+        body.appendChild(from);
+        body.appendChild(success);
+        return body;
+    }
+
+}

xml/src/main/java/com/baeldung/xmlhtml/mustache/MustacheTransformer.java

@@ -0,0 +1,30 @@
+package com.baeldung.xmlhtml.mustache;
+
+import com.baeldung.xmlhtml.stax.StaxTransformer;
+import com.github.mustachejava.DefaultMustacheFactory;
+import com.github.mustachejava.Mustache;
+import com.github.mustachejava.MustacheFactory;
+
+import javax.xml.stream.XMLStreamException;
+import java.io.IOException;
+import java.io.StringWriter;
+import java.io.Writer;
+
+public class MustacheTransformer {
+    private StaxTransformer staxTransformer;
+    private String templateFile;
+
+    public MustacheTransformer(StaxTransformer staxTransformer, String templateFile) {
+        this.staxTransformer = staxTransformer;
+        this.templateFile = templateFile;
+    }
+
+    public String html() throws IOException, XMLStreamException {
+        MustacheFactory mf = new DefaultMustacheFactory();
+        Mustache mustache = mf.compile(templateFile);
+        Writer output = new StringWriter();
+        mustache.execute(output, staxTransformer.buildMap());
+        output.flush();
+        return output.toString();
+    }
+}

xml/src/main/java/com/baeldung/xmlhtml/pojo/stax/Body.java

@@ -1,23 +0,0 @@
-package com.baeldung.xmlhtml.pojo.stax;
-
-public class Body {
-
-    private CustomElement customElement;
-
-    public CustomElement getCustomElement() {
-        return customElement;
-    }
-    public void setCustomElement(CustomElement customElement) {
-        this.customElement = customElement;
-    }
-
-    private NestedElement nestedElement;
-
-    public NestedElement getNestedElement() {
-        return nestedElement;
-    }
-    public void setNestedElement(NestedElement nestedElement) {
-        this.nestedElement = nestedElement;
-    }
-
-}

xml/src/main/java/com/baeldung/xmlhtml/pojo/stax/CustomElement.java

@@ -1,13 +0,0 @@
-package com.baeldung.xmlhtml.pojo.stax;
-
-public class CustomElement {
-
-    private String value;
-
-    public String getValue() {
-        return value;
-    }
-    public void setValue(String value) {
-        this.value = value;
-    }
-}

xml/src/main/java/com/baeldung/xmlhtml/pojo/stax/NestedElement.java

@@ -1,13 +0,0 @@
-package com.baeldung.xmlhtml.pojo.stax;
-
-public class NestedElement {
-
-    private CustomElement customElement;
-
-    public CustomElement getCustomElement() {
-        return customElement;
-    }
-    public void setCustomElement(CustomElement customElement) {
-        this.customElement = customElement;
-    }
-}

xml/src/main/java/com/baeldung/xmlhtml/stax/StaxTransformer.java

@@ -0,0 +1,89 @@
+package com.baeldung.xmlhtml.stax;
+
+import javax.xml.stream.*;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.StringWriter;
+import java.io.Writer;
+import java.util.HashMap;
+import java.util.Map;
+
+public class StaxTransformer {
+
+    private XMLStreamReader input;
+
+    public StaxTransformer(String resourcePath) throws FileNotFoundException, XMLStreamException {
+        XMLInputFactory factory = XMLInputFactory.newInstance();
+        factory.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES, Boolean.FALSE);
+        factory.setProperty(XMLInputFactory.SUPPORT_DTD, Boolean.FALSE);
+        input = factory.createXMLStreamReader(new FileInputStream(resourcePath));
+    }
+
+    public String html() throws XMLStreamException {
+        Map<String, String> map = buildMap();
+        Writer output = new StringWriter();
+        XMLStreamWriter writer = XMLOutputFactory
+          .newInstance()
+          .createXMLStreamWriter(output);
+        //Head
+        writer.writeDTD("<!DOCTYPE html>");
+        writer.writeCharacters(String.format("%n"));
+        writer.writeStartElement("html");
+        writer.writeAttribute("lang", "en");
+        writer.writeCharacters(String.format("%n"));
+        writer.writeStartElement("head");
+        writer.writeCharacters(String.format("%n"));
+        writer.writeDTD("<META http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\">");
+        writer.writeCharacters(String.format("%n"));
+        writer.writeStartElement("title");
+        writer.writeCharacters(map.get("heading"));
+        writer.writeEndElement();
+        writer.writeCharacters(String.format("%n"));
+        writer.writeEndElement();
+        writer.writeCharacters(String.format("%n"));
+        //Body
+        writer.writeStartElement("body");
+        writer.writeCharacters(String.format("%n"));
+        writer.writeStartElement("p");
+        writer.writeCharacters(map.get("from"));
+        writer.writeEndElement();
+        writer.writeCharacters(String.format("%n"));
+        writer.writeStartElement("p");
+        writer.writeCharacters(map.get("content"));
+        writer.writeEndElement();
+        writer.writeCharacters(String.format("%n"));
+        writer.writeEndElement();
+        writer.writeCharacters(String.format("%n"));
+        writer.writeEndDocument();
+        writer.writeCharacters(String.format("%n"));
+        writer.flush();
+        writer.close();
+        return output.toString();
+    }
+
+    public Map<String, String> buildMap() throws XMLStreamException {
+        Map<String, String> map = new HashMap<>();
+        while (input.hasNext()) {
+            input.next();
+            if (input.isStartElement()) {
+                if (input
+                  .getLocalName()
+                  .equals("heading")) {
+                    map.put("heading", input.getElementText());
+                }
+                if (input
+                  .getLocalName()
+                  .equals("from")) {
+                    map.put("from", String.format("from: %s", input.getElementText()));
+                }
+                if (input
+                  .getLocalName()
+                  .equals("content")) {
+                    map.put("content", input.getElementText());
+                }
+            }
+        }
+        input.close();
+        return map;
+    }
+}

xml/src/test/java/com/baeldung/xml/attribute/Dom4jProcessorUnitTest.java

@@ -47,7 +47,9 @@ public class Dom4jProcessorUnitTest {
         String expectedXml = new String(Files.readAllBytes((Paths.get(getClass().getResource("/xml/attribute_expected.xml")
             .toURI()))));
 
-        String result = transformer.modifyAttribute(attribute, oldValue, newValue);
+        String result = transformer
+          .modifyAttribute(attribute, oldValue, newValue)
+          .replaceAll("(?m)^[ \t]*\r?\n", "");//Delete extra spaces added by Java 11
 
         assertThat(result).and(expectedXml)
             .areSimilar();

xml/src/test/java/com/baeldung/xml/attribute/JooxProcessorUnitTest.java

@@ -47,7 +47,9 @@ public class JooxProcessorUnitTest {
         String expectedXml = new String(Files.readAllBytes((Paths.get(getClass().getResource("/xml/attribute_expected.xml")
             .toURI()))));
 
-        String result = transformer.modifyAttribute(attribute, oldValue, newValue);
+        String result = transformer
+          .modifyAttribute(attribute, oldValue, newValue)
+          .replaceAll("(?m)^[ \t]*\r?\n", "");//Delete extra spaces added by Java 11
 
         assertThat(result).and(expectedXml)
             .areSimilar();

xml/src/test/java/com/baeldung/xmlhtml/freemarker/FreemarkerTransformerUnitTest.java

@@ -0,0 +1,32 @@
+package com.baeldung.xmlhtml.freemarker;
+
+import com.baeldung.xmlhtml.stax.StaxTransformer;
+import freemarker.template.TemplateException;
+import org.junit.jupiter.api.Test;
+
+import javax.xml.stream.XMLStreamException;
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class FreemarkerTransformerUnitTest {
+
+    @Test
+    public void givenXml_whenTransform_thenGetHtml() throws IOException, URISyntaxException, XMLStreamException, TemplateException {
+        String expectedHtml = new String(Files.readAllBytes((Paths.get(getClass()
+          .getResource("/xmlhtml/notification.html")
+          .toURI()))));
+        StaxTransformer staxTransformer = new StaxTransformer("src/test/resources/xmlhtml/notification.xml");
+        String templateFile = "freemarker.html";
+        String templateDirectory = "src/test/resources/templates";
+        FreemarkerTransformer transformer = new FreemarkerTransformer(staxTransformer, templateDirectory, templateFile);
+
+        String result = transformer.html();
+
+        assertThat(result).isEqualTo(expectedHtml);
+    }
+
+}

xml/src/test/java/com/baeldung/xmlhtml/jaxp/JaxpTransformerUnitTest.java

@@ -0,0 +1,33 @@
+package com.baeldung.xmlhtml.jaxp;
+
+import org.junit.jupiter.api.Test;
+import org.xml.sax.SAXException;
+
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.transform.TransformerException;
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class JaxpTransformerUnitTest {
+
+    @Test
+    public void givenXml_whenTransform_thenGetHtml() throws IOException, SAXException, ParserConfigurationException, TransformerException, URISyntaxException {
+        String path = getClass()
+          .getResource("/xmlhtml/notification.xml")
+          .toString();
+        String expectedHtml = new String(Files.readAllBytes((Paths.get(getClass()
+          .getResource("/xmlhtml/notification.html")
+          .toURI()))));
+        JaxpTransformer transformer = new JaxpTransformer(path);
+
+        String result = transformer
+          .html()
+          .replaceAll("(?m)^\\s+", "");//Delete extra spaces added by Java 11
+
+        assertThat(result).isEqualTo(expectedHtml);
+    }
+}

xml/src/test/java/com/baeldung/xmlhtml/mustache/MustacheTransformerUnitTest.java

@@ -0,0 +1,30 @@
+package com.baeldung.xmlhtml.mustache;
+
+import com.baeldung.xmlhtml.stax.StaxTransformer;
+import org.junit.jupiter.api.Test;
+
+import javax.xml.stream.XMLStreamException;
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class MustacheTransformerUnitTest {
+
+    @Test
+    public void givenXml_whenTransform_thenGetHtml() throws IOException, URISyntaxException, XMLStreamException {
+        String expectedHtml = new String(Files.readAllBytes((Paths.get(getClass()
+          .getResource("/xmlhtml/notification.html")
+          .toURI()))));
+        StaxTransformer staxTransformer = new StaxTransformer("src/test/resources/xmlhtml/notification.xml");
+        String templateFile = "src/test/resources/templates/template.mustache";
+        MustacheTransformer transformer = new MustacheTransformer(staxTransformer, templateFile);
+
+        String result = transformer.html();
+
+        assertThat(result).isEqualTo(expectedHtml);
+    }
+
+}

xml/src/test/java/com/baeldung/xmlhtml/stax/StaxTransformerUnitTest.java

@@ -0,0 +1,28 @@
+package com.baeldung.xmlhtml.stax;
+
+import org.junit.jupiter.api.Test;
+
+import javax.xml.stream.XMLStreamException;
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class StaxTransformerUnitTest {
+
+    @Test
+    public void givenXml_whenTransform_thenGetHtml() throws IOException, URISyntaxException, XMLStreamException {
+        String path = "src/test/resources/xmlhtml/notification.xml";
+        String expectedHtml = new String(Files.readAllBytes((Paths.get(getClass()
+          .getResource("/xmlhtml/notification.html")
+          .toURI()))));
+        StaxTransformer transformer = new StaxTransformer(path);
+
+        String result = transformer.html();
+
+        assertThat(result).isEqualTo(expectedHtml);
+    }
+
+}

xml/src/test/resources/templates/freemarker.html

@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<META http-equiv="Content-Type" content="text/html; charset=UTF-8">
+<title>${heading}</title>
+</head>
+<body>
+<p>${from}</p>
+<p>${content}</p>
+</body>
+</html>

xml/src/test/resources/templates/template.mustache

@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<META http-equiv="Content-Type" content="text/html; charset=UTF-8">
+<title>{{heading}}</title>
+</head>
+<body>
+<p>{{from}}</p>
+<p>{{content}}</p>
+</body>
+</html>

xml/src/test/resources/xmlhtml/notification.html

@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<META http-equiv="Content-Type" content="text/html; charset=UTF-8">
+<title>Build #7 passed</title>
+</head>
+<body>
+<p>from: builds@baeldung.com</p>
+<p>Success: The Jenkins CI build passed</p>
+</body>
+</html>

xml/src/test/resources/xmlhtml/notification.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<notification>
+  <from>builds@baeldung.com</from>
+  <heading>Build #7 passed</heading>
+  <content>Success: The Jenkins CI build passed</content>
+</notification>