Question

Create a program called ReadNames FromXML that reads the file lab10.xml (also in a ZIP file here for download), stores each string of the file into an array list and displays each name. On the documentation page for XMLDecoder you will find that exceptions can arise when this program runs: FileNotFoundException: when the XMLDecoder object is created. ArrayIndexOutofBoundsException: when the input stream has no more objects. For this exception you need the import: java.lang. ArrayIndexOutOfBounds Exception. Modify this program in two ways: a. it should terminate with a message "file not found" if a FileNotFoundException occurs. b. assume you do not know how many names are in the file -- it should read as many names as the file holds. - Use ArrayIndexOutOfBounds Exception to accomplish this

do this in java and as simple as possible as i am new to this.
The lab10.xml is here

and the zip file is here

Thank you

Answer 1

Please find the code and its output below.

 import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.DocumentBuilder; import org.w3c.dom.Document; import org.w3c.dom.NodeList; import org.w3c.dom.Node; import org.w3c.dom.Element; import java.io.File; import java.io.FileNotFoundException; import java.io.IOException; import java.util.ArrayList; import java.util.List; public class ReadXMLFileExample1 { public static void main(String argv[])throws IOException , FileNotFoundException,ArrayIndexOutOfBoundsException , Exception { try { List<String> ar = new ArrayList<String>(); File file = new File("C:\\Users\\escuhao\\Desktop\\XMLFile.xml"); // Put the path of the XMLFile.xml DocumentBuilderFactory fact = DocumentBuilderFactory.newInstance();//It is an instance that gives a document builder DocumentBuilder build = fact.newDocumentBuilder(); //This is an instance of builder to parse the specified xml file (XMLFile.xml) Document doc = build.parse(file); doc.getDocumentElement().normalize(); NodeList nl = doc.getElementsByTagName("java"); // This is the root element NodeList nl1 = doc.getElementsByTagName("string"); int length = nl.getLength(); int length1 = nl1.getLength(); int j=0 ; System.out.println(length1+" names are found in the .xml file:\n "); for (j = 0; j < length; j++) { Node node = nl.item(j); Element eElement = (Element) node; for (int i=0;i<length1;i++ ) { System.out.println(eElement.getElementsByTagName("string").item(i).getTextContent()); ar.add(eElement.getElementsByTagName("string").item(i).getTextContent()); } System.out.println("\nAll names are stored inside the array : \n" +ar); } } catch (FileNotFoundException e) { System.err.println("File not found "); } catch (ArrayIndexOutOfBoundsException e) { System.err.println("Array index out of bounds !!!"); } catch (Exception e) {     System.err.println("An exception occurs"); } } }

OUTPUT:

<terminated> ReadXMLFile Example 1 [Java Application] C:\Program FilesVava\jdk-12.0.2\bin\javaw.exe (r 10 names are found in the .xml file: Harry Ron Hermione Luna Draco Neville Seamus Ginny Fred George All names are stored inside the array : [Harry, Ron, Hermione, Luna, Draco, Neville, Seamus, Ginny, Fred, George]

If the required file is not found then we wil get the below message.

10USD 11 - LISENSIILOOTUS 26 int length = nl.getLength(); 27 int length1 = n11.getLength(); Problems @ Javadoc Declaration Console X <terminated> ReadXMLFile Example 1 [Java Application) C:\Program Files\Java\jdk-12 File not found