/**
* The given code is provided to assist you to complete the required tasks. But the given code is
* often incomplete. You have to read and understand the given code carefully, before you can apply
* the code properly. You might need to implement additional procedures, such as error checking and
* handling, in order to apply the code properly.
*/
// you need to import some xml libraries
import java.io.*;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;
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;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.reflect.TypeToken;
import com.google.gson.stream.JsonReader;
// import any standard library if needed
/**
* A book collection holds 0 or more books in a collection.
*/
public class BookCollection {
private List
/**
* Creates a new collection with no books by default.
*/
public BookCollection() {
this.books = new ArrayList
}
/**
* Creates a new book collection with the specified list of books pre-defined.
*
* @param books A books list.
*/
public BookCollection(List
this.books = books;
}
/**
* Returns the current list of books stored by this collection.
*
* @return A (mutable) list of books.
*/
public List
return books;
}
/**
* Sets the list of books in this collection to the specified value.
*/
public void setList(List
this.books = books;
}
/**
* A simple human-readable toString implementation. Not particularly useful to save to disk.
*
* @return A human-readable string for printing
*/
@Override
public String toString() {
return this.books.stream().map(book -> ” – ” + book.display() + “\n”)
.collect(Collectors.joining());
}
/**
* Saves this collection to the specified “bespoke” file.
*
* @param file The path to a file.
*/
public void saveToBespokeFile(File file) {
// TODO: Implement this function yourself. The specific hierarchy is up to you,
// but it must be in a bespoke format and should match the
// load function.
try {
BufferedWriter bw = new BufferedWriter(new FileWriter(file));
for (Book b : books) {
String line = b.title + “/” + b.authorName + “/” + b.yearReleased + “/” + b.bookGenre.display();
bw.write(line);
bw.newLine();
}
bw.close();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* Saves this collection to the specified JSON file.
*
* @param file The path to a file.
*/
public void saveToJSONFile(File file) {
// TODO: Implement this function yourself. The specific hierarchy is up to you,
// but it must be in a JSON format and should match the load function.
Gson gson = new GsonBuilder().setPrettyPrinting().create();
try (FileWriter writer = new FileWriter(file)) {
gson.toJson(getList(), writer);
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* Saves this collection to the specified XML file.
*
* @param file The path to a file.
*/
public void saveToXMLFile(File file) {
// TODO: Implement this function yourself. The specific hierarchy is up to you,
// but it must be in an XML format and should match the
// load function.
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.newDocument();
Element rootEle = doc.createElement(“Books”);
doc.appendChild(rootEle);
for (Book book : books) {
Element BookEle = doc.createElement(“Book”);
rootEle.appendChild(BookEle);
Element title = doc.createElement(“Title”);
title.appendChild(doc.createTextNode(book.title));
BookEle.appendChild(title);
Element authorName = doc.createElement(“AuthorName”);
authorName.appendChild(doc.createTextNode(book.authorName));
BookEle.appendChild(authorName);
Element year = doc.createElement(“Year”);
year.appendChild(doc.createTextNode(Integer.toString(book.yearReleased)));
BookEle.appendChild(year);
Element genre = doc.createElement(“Genre”);
genre.appendChild(doc.createTextNode(book.bookGenre.name));
BookEle.appendChild(genre);
}
Transformer tran = TransformerFactory.newInstance().newTransformer();
tran.setOutputProperty(OutputKeys.ENCODING, “utf-8”);
tran.setOutputProperty(OutputKeys.INDENT, “yes”);
DOMSource source = new DOMSource(doc);
StreamResult result = new StreamResult(file);
tran.transform(source, result);
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* Load a pre-existing book collection from a “bespoke” file.
*
* @param file The file to load from. This is guaranteed to exist.
* @return An initialised book collection.
*/
public static BookCollection loadFromBespokeFile(File file) {
// TODO: Implement this function yourself.
BookCollection result = null;
try {
BufferedReader br = new BufferedReader(new FileReader(file));
String line;
List
while ((line = br.readLine()) != null) {
String[] tokens = line.split(“/”);
int year = Integer.parseInt(tokens[2]);
// convert String to BookGenre
BookGenre genre = null;
if (tokens[3].compareTo(“Action (Fiction)”)==0)
genre = BookGenre.FICTION_ACTION;
else if (tokens[3].compareTo(“Comedy (Fiction)”)==0)
genre = BookGenre.FICTION_COMEDY;
else if (tokens[3].compareTo(“Fantasy (Fiction)”)==0)
genre = BookGenre.FICTION_FANTASY;
else if (tokens[3].compareTo(“Non-Fiction”)==0)
genre = BookGenre.NON_FICTION;
Book book = new Book(tokens[0], tokens[1], year, genre);
thisBook.add(book);
}
result = new BookCollection(thisBook);
br.close();
} catch (IOException e) {
e.printStackTrace();
}
return result;
}
/**
* Load a pre-existing book collection from a JSON file.
*
* @param file The file to load from. This is guaranteed to exist.
* @return An initialised book collection.
*/
public static BookCollection loadFromJSONFile(File file) {
// TODO: Implement this function yourself.
List
Gson gson = new Gson();
JsonReader jRead = null;
final Type BOOK_LIST = new TypeToken
try {
jRead = new JsonReader(new FileReader(file));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
BookCollection bookCollection = new BookCollection(gson.fromJson(jRead, BOOK_LIST));
return bookCollection;
}
/**
* Load a pre-existing book collection from an XML file.
*
* @param file The file to load from. This is guaranteed to exist.
* @return An initialised book collection.
*/
public static BookCollection loadFromXMLFile(File file) {
// TODO: Implement this function yourself.
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
List
try {
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.parse(file);
doc.getDocumentElement().normalize();
NodeList nl = doc.getElementsByTagName(“Book”);
for (int i = 0; i < nl.getLength(); i++) { Node n = nl.item(i); if (n.getNodeType() == Node.ELEMENT_NODE) { Element elem = (Element) n; String title = elem.getElementsByTagName("Title").item(0).getTextContent(); String authorName = elem.getElementsByTagName("AuthorName").item(0).getTextContent(); int year = Integer.parseInt(elem.getElementsByTagName("Year").item(0).getTextContent()); String genre = elem.getElementsByTagName("Genre").item(0).getTextContent(); BookGenre bgenre = findEnumbyName(genre); Book lbook = new Book(title, authorName, year, bgenre); loadbook.add(lbook); } } } catch (Exception e) { e.printStackTrace(); } BookCollection bookCollection = new BookCollection(loadbook); return bookCollection; } public static BookGenre findEnumbyName(String name) { for (BookGenre bookGenre : BookGenre.values()) { if (bookGenre.display().equals(name)) { return bookGenre; } } throw new IllegalArgumentException("name is not support"); } }