Thực hành sử dụng XML trong Java Lab 3

Processing XML Using Java Lab 03 Extensible Stylesheet Transformation Language Mục tiêu - Sử dụng transformer chuyển đổi file xml xsl (html) - Sử dụng XPath Expression để lấy liệu theo Expression từ file xml - Sử dụng JAXP APIs trình xử lý XPath Phần I Bài tập step by step Bài 3.1 In nội dung file emp.xsl chuyển đổi từ file Employees.xml:  Employees.xml  Emp.xsl IT Research Department @BKAP 2015 Trang / 15 Architecting Applications for the Web Step 1: Tạo project java netbean  File  New Project  Java  Java Application  Project Name: Đặt tên Project ESTLExample Step 2: Tạo File Employees.xml  Project  New  Other  XML  XML Document  Employees.xml Allen Smith Alaska M IT Research Department @BKAP 2015 Trang / 15 Processing XML Using Java John Davis California M Bob Thomson Kansas M Step 3: Tạo File emp.xsl  Project  New  Other  XML  XSL Stylesheet  Emp.xsl IT Research Department @BKAP 2015 Trang / 15 Architecting Applications for the Web XML Data Admin Employee Step 4: Tạo lớp TransformDOM.java để chuyển đổi XML với XSL  TransformDOM.java package estlexample; import javax.xml.transform.Transformer; import javax.xml.transform.TransformerFactory; import javax.xml.transform.dom.DOMSource; import javax.xml.transform.stream.StreamResult; import javax.xml.transform.stream.StreamSource; import org.w3c.dom.Document; /** * * @author DELL */ public class TransformDOM { public static void TransformXMLToXsl(Document doc) { try { //Create Dom Source DOMSource source = new DOMSource(doc); //Create Transformer Factory TransformerFactory transformerFactory = TransformerFactory.newInstance(); //Print the type of XSLT processor implemented IT Research Department @BKAP 2015 Trang / 15 Processing XML Using Java System.out.println(transformerFactory.getClass()); //Create Transformer from Transformer Factory - Applying the stylesheet in the transformation Transformer tranformer = transformerFactory.newTransformer(new StreamSource("emp.xsl")); //An object to hold the results StreamResult result = new StreamResult(System.out); tranformer.transform(source, result); } catch (Exception ex) { ex.printStackTrace(); } } }  Cấu trúc project sau hoàn thành Step 5: Triển khai hàm main ứng dụng  ESTLExample.java package estlexample; import java.io.File; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import org.w3c.dom.Document; /** * * @author DELL */ public class ESTLExample { /** * @param args the command line arguments IT Research Department @BKAP 2015 Trang / 15 Architecting Applications for the Web */ public static void main(String[] args) { try { File file = new File("Employees.xml"); DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); factory.setNamespaceAware(true); DocumentBuilder builder = factory.newDocumentBuilder(); Document doc = builder.parse(file); //Transform the XML file into XSL TransformDOM tfd = new TransformDOM(); tfd.TransformXMLToXsl(doc); } catch (Exception ex) { ex.printStackTrace(); } } } Step 6: Build and Run ứng dụng Bài 3.2 Sử dụng biểu thức XPath in tất giá trị node firstname có file Employees.xml Step 1: Tạo lớp XpathExpressions.java để in tất giá trị node firstname  XpathExpressions.java package estlexample; IT Research Department @BKAP 2015 Trang / 15 Processing XML Using Java import javax.xml.xpath.XPath; import javax.xml.xpath.XPathConstants; import javax.xml.xpath.XPathFactory; import org.w3c.dom.Document; import org.w3c.dom.NodeList; /** * * @author DELL */ public class XPathExpressions { public static void ExpressionFirstName(Document doc) { try { //Create XPath Factory XPathFactory xpathfac = XPathFactory.newInstance(); //Create XPath XPath xPath = xpathfac.newXPath(); //Create expression String expression = "/employees/employee/firstname"; //print expression System.out.println(expression); //get node list form Employees.xml and expression NodeList nodeList = (NodeList) xPath.compile(expression).evaluate(doc, XPathConstants.NODESET); for (int i = 0; i < nodeList.getLength(); i++) { //print node fristname System.out.println(nodeList.item(i) getFirstChild().getNodeValue()); } } catch (Exception e) { e.printStackTrace(); } } }  Cấu trúc project sau hoàn thành IT Research Department @BKAP 2015 Trang / 15 Architecting Applications for the Web Step 2: Triển khai hàm main ứng dụng  ESTLExample.java package estlexample; import java.io.File; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import org.w3c.dom.Document; /** * * @author DELL */ public class ESTLExample { /** * @param args the command line arguments */ public static void main(String[] args) { try { File file = new File("Employees.xml"); DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); factory.setNamespaceAware(true); DocumentBuilder builder = factory.newDocumentBuilder(); Document doc = builder.parse(file); //Transform the XML file into XSL // TransformDOM tfd = new TransformDOM(); // tfd.TransformXMLToXsl(doc); XPathExpressions xpath = new XPathExpressions(); xpath.ExpressionFirstName(doc); } catch (Exception ex) { ex.printStackTrace(); IT Research Department @BKAP 2015 Trang / 15 Processing XML Using Java } } } Step 3: Build and Run ứng dụng Bài 3.3 Sử dụng XPath Expression lấy liệu từ file Employees.xml  In tất giá trị node với điều kiện giá trị attribute element employee có id =”112”  In giá trị node element employee có giá trị node location = “Kansas” Step 1: Tạo method ExpressionEmployeeAttribute – in tất node có giá trị attribute element employee có id = “112” ExpressionNodeValue – in giá trị node element employee có giá trị node location = “Kansas” XpathExpression.java  XpathExpresion.java … public static void ExpressionEmployeeAttribute(Document doc) { try { //Create XPath Factory XPathFactory xpathfac = XPathFactory.newInstance(); //Create XPath XPath xPath = xpathfac.newXPath(); IT Research Department @BKAP 2015 Trang / 15 Architecting Applications for the Web //Create expression String expression = "/employees/employee[@id='112']"; //print expression System.out.println(expression); //Get node employee from Employees.xml and expression Node node = (Node) xPath.compile(expression).evaluate(doc, XPathConstants.NODE); if (null != node) { NodeList nodeList = node.getChildNodes(); for (int i = 0; null != nodeList && i < nodeList.getLength(); i++) { //get all child node of node employee Node nod = nodeList.item(i); //print node if (nod.getNodeType() == Node.ELEMENT_NODE) { System.out.println(nodeList.item(i).getNodeName() + " : " + nod.getFirstChild().getNodeValue()); } } } } catch (Exception ex) { ex.printStackTrace(); } } public static void ExpressionNodeValue(Document doc) { try { //Create XPath Factory XPathFactory xpathfac = XPathFactory.newInstance(); //Create XPath XPath xPath = xpathfac.newXPath(); //Create expression String expression = "/employees/employee[location='Kansas']"; //print expression System.out.println(expression); //Get node employee from Employees.xml and expression Node node = (Node) xPath.compile(expression).evaluate(doc, XPathConstants.NODE); if (null != node) { //get all child node of node employee NodeList nodeList = node.getChildNodes(); for (int i = 0; null != nodeList && i < nodeList.getLength(); i++) { IT Research Department @BKAP 2015 Trang 10 / 15 Processing XML Using Java //print node Node nod = nodeList.item(i); if (nod.getNodeType() == Node.ELEMENT_NODE) { System.out.println(nodeList.item(i).getNodeName() + " : " + nod.getFirstChild().getNodeValue()); } } } } catch (Exception ex) { ex.printStackTrace(); } } Step 2: Triển khai hàm main ứng dụng package estlexample; import java.io.File; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import org.w3c.dom.Document; /** * * @author DELL */ public class ESTLExample { /** * @param args the command line arguments */ public static void main(String[] args) { try { File file = new File("Employees.xml"); DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); factory.setNamespaceAware(true); DocumentBuilder builder = factory.newDocumentBuilder(); Document doc = builder.parse(file); //Transform the XML file into XSL // TransformDOM tfd = new TransformDOM(); // tfd.TransformXMLToXsl(doc); IT Research Department @BKAP 2015 Trang 11 / 15 Architecting Applications for the Web XPathExpressions xpath = new XPathExpressions(); xpath.ExpressionFirstName(doc); xpath.ExpressionEmployeeAttribute(doc); xpath.ExpressionNodeValue(doc); } catch (Exception ex) { ex.printStackTrace(); } // } } Step 3: Build and Run ứng dụng Bài 3.4 Chỉnh employee có attribute giá trị id = “112” có node location có giá trị “Kansas” IT Research Department @BKAP 2015 Trang 12 / 15 Processing XML Using Java  In hình giá trị node firstname node có giá trị node location Kansas  In hình tổng số node có giá trị node location Kansas  Nếu tổng số node có giá trị node location Kansas nhiều in hình “There are more than one employee located at Kansas” Step 1: Tạo method XPathUsingJAXPAPI lớp XpathExpression để in hình giá trị node firstname, tổng số node, kiểm tra tổng số node có lớn khơng node có giá trị node location Kansas  XpathExpression.java … public static void XPathUsingJAXPAPI(Document doc) { try { //Create an XPathFactory XPathFactory xFactory = XPathFactory.newInstance(); //Create an XPath object XPath xpath = xFactory.newXPath(); //Compile the XPath expression XPathExpression expr = xpath.compile("/employees/employee[location='Kansas']/firstname/text()"); //Run the query and get a nodeset Object result = expr.evaluate(doc, XPathConstants.NODESET); //Cast the result to a DOM NodeList nodes = (NodeList) result; for (int i = 0; i < nodes.getLength(); i++) { System.out.println(nodes.item(i).getNodeValue()); } /* XPath expression to get the number of peoplelocated at Kansas */ expr = xpath.compile("count(/employees/employee[location='Kansas'])"); /* Run the query and get the number of nodes*/ Double number = (Double) expr.evaluate(doc, XPathConstants.NUMBER); System.out.println("Number of objects " + number); /* Check more than one employeelocated at Kansas*/ expr = xpath.compile("count(/employees/employee[location='Kansas']) >1"); /* Run the query and get the number of nodes*/ IT Research Department @BKAP 2015 Trang 13 / 15 Architecting Applications for the Web Boolean check = (Boolean) expr.evaluate(doc, XPathConstants.BOOLEAN); if (check == true) { System.out.println("There are more than one employee located at Kansas"); } } catch (Exception ex) { ex.printStackTrace(); } } Step 2: Triển khai hàm main ứng dụng package estlexample; import java.io.File; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import org.w3c.dom.Document; /** * * @author DELL */ public class ESTLExample { /** * @param args the command line arguments */ public static void main(String[] args) { try { File file = new File("Employees.xml"); DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); factory.setNamespaceAware(true); DocumentBuilder builder = factory.newDocumentBuilder(); Document doc = builder.parse(file); //Transform the XML file into XSL // TransformDOM tfd = new TransformDOM(); // tfd.TransformXMLToXsl(doc); XPathExpressions xpath = new XPathExpressions(); // xpath.ExpressionFirstName(doc); // xpath.ExpressionEmployeeAttribute(doc); // xpath.ExpressionNodeValue(doc); IT Research Department @BKAP 2015 Trang 14 / 15 Processing XML Using Java xpath.XPathUsingJAXPAPI(doc); } catch (Exception ex) { ex.printStackTrace(); } } } Step 3: Build and Run ứng dụng Phần II Bài tập tự làm IT Research Department @BKAP 2015 Trang 15 / 15 ... TransformDOM .java để chuyển đổi XML với XSL  TransformDOM .java package estlexample; import javax .xml. transform.Transformer; import javax .xml. transform.TransformerFactory; import javax .xml. transform.dom.DOMSource;... Department @BKAP 2015 Trang / 15 Processing XML Using Java } } } Step 3: Build and Run ứng dụng Bài 3. 3 Sử dụng XPath Expression lấy liệu từ file Employees .xml  In tất giá trị node với điều kiện... Processing XML Using Java import javax .xml. xpath.XPath; import javax .xml. xpath.XPathConstants; import javax .xml. xpath.XPathFactory; import org.w3c.dom.Document; import org.w3c.dom.NodeList; /** * * @author