CS计算机代考程序代写 Java import java.io.File;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.w3c.dom.Element;

/**
* IMPORTANT: This class is incomplete. Please look for “TODO” comments.
*
* Save() method is already given. Please implement load() method to load XML
* files and insert() method to insert a new customer to XML files.
*
* Each customer must have an ID value, but may not have all the following column values:
* Name, Address, City, Postcode, Country. Please see test cases in XMLTableTest.java.
*
*/
public class XMLTable {

/**
* Save all records to the XML file
*/
public void save(String tableName, List customers) {

File f = new File(FileUtil.getTableFileName(tableName));

DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
try {
// make the xml tree
// use factory to get the instance of document builder
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.newDocument();
// Root element
Element rootElem = doc.createElement(Customer.KEY_ROOT);
doc.appendChild(rootElem);

for (Customer customer : customers) {
Element customerElem = doc.createElement(Customer.KEY_ELEMENT);
rootElem.appendChild(customerElem);

// child element under
Element cid = doc.createElement(Customer.KEY_ID);
cid.appendChild(doc.createTextNode(Integer.toString(customer.getId())));
customerElem.appendChild(cid);

if (customer.getName() != null) {
Element name = doc.createElement(Customer.KEY_NAME);
name.appendChild(doc.createTextNode(customer.getName()));
customerElem.appendChild(name);
}

if (customer.getAddress() != null) {
Element address = doc.createElement(Customer.KEY_ADDRESS);
address.appendChild(doc.createTextNode(customer.getAddress()));
customerElem.appendChild(address);
}

if (customer.getCity() != null) {
Element city = doc.createElement(Customer.KEY_CITY);
city.appendChild(doc.createTextNode(customer.getCity()));
customerElem.appendChild(city);
}

if (customer.getPostCode() != null) {
Element postCode = doc.createElement(Customer.KEY_POSTCODE);
postCode.appendChild(doc.createTextNode(customer.getPostCode()));
customerElem.appendChild(postCode);
}

if (customer.getCountry() != null) {
Element country = doc.createElement(Customer.KEY_COUNTRY);
country.appendChild(doc.createTextNode(customer.getCountry()));
customerElem.appendChild(country);
}
}
// save the xml file
// Transformer is for process XML from a variety of sources and write the
// transformation
// output to a variety of sinks
Transformer transformer = TransformerFactory.newInstance().newTransformer();

// set xml encoding to utf-8
transformer.setOutputProperty(OutputKeys.ENCODING, “utf-8”);
// pretty print
transformer.setOutputProperty(OutputKeys.INDENT, “yes”);

DOMSource source = new DOMSource(doc);
StreamResult result = new StreamResult(f);
transformer.transform(source, result);

} catch (Exception e) {
e.printStackTrace();
}
}

/**
* Get all records from the XML file
*/
public List load(String tableName) {

List customers = new ArrayList<>();

File f = new File(FileUtil.getTableFileName(tableName));
if (!f.exists()) {
return customers;
}

// TODO: Complete this method
// START YOUR CODE

// END YOUR CODE

return customers;
}

/**
* Insert a new customer to XML files.
*
*
*/
public void insert(String tableName, Customer customer) {

// TODO: Complete this method
// START YOU CODE
// HINT: insert the given customer to the XML file.
// You can call the load() and save() methods

// END YOUR CODE
}
}