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vault backup: 2024-03-05 13:01:43

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George Wilkinson
2024-03-05 13:01:43 +00:00
parent 8f7a395bdb
commit 8ce640b4ba
44 changed files with 1177 additions and 177 deletions
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160
Semester 2/Programming 2/Project/Part 2/Library.java
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@@ -1,22 +1,27 @@
/**
* Write a description of class Library here.
* Class to create objects of a Library, which can hold and report on assets held within
*
* @author (your name)
* @version (a version number or a date)
* @George Wilkinson
* @2.0
*/
// Import all required libraries. Not using .* as it is not good practice due to potential conflicts.
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Scanner;
import java.util.Random;
import java.io.File;
import java.io.IOException;
import java.awt.FileDialog;
import java.awt.Frame;
import java.io.PrintWriter;
public class Library
{
private ArrayList<LibraryItem> itemList; // Initialise an ArrayList of name itemList to store LibraryItems
private ArrayList<LibraryItem> itemList; // Initialise an ArrayList of name itemList to store Library Items
private ArrayList<LibraryUser> userList; // Initialise an ArrayList of name userList to store Library Users
private HashSet<String> uuidSet; // Initialise a Hash Set of name uuidSet ( unique user identifier ) to store unique user IDs for efficient O(1) searching
/*
* Constructor for objects of class Library
@@ -24,6 +29,8 @@ public class Library
public Library()
{
itemList = new ArrayList<LibraryItem>();
userList = new ArrayList<LibraryUser>();
uuidSet = new HashSet<String>();
}
/*
@@ -35,17 +42,110 @@ public class Library
}
/*
* Prints to the terminal all items in the itemList
* Appends a LibraryUser to the userList.
*/
public void printAllItems()
public void storeUser( LibraryUser user )
{
for( LibraryItem item : itemList )
userList.add( user );
if ( user.getUserID().equals( "unknown" ) )
{
item.printDetails();
user.setUserID( generateUserID( "AB-", 6 ) );
}
}
public void readItemData() //throws IOException
/*
* Returns a random unique user ID by specifying
* @prefix - arbitrary alphanumeric prefix
* @length - length of numeric ID
* and returning a unique user id
* @uuid - a unique string starting with @prefix, and concat. with a random number
*
* Example: length = 6, expected result should be under 999,999 and above 99,999.
* If we just use 10^(length), this would generate any number under 1,000,000.
* This is an issue since any integers below 100,000 can be used, which would be incorrect.
* By using the offset of a factor of 10 below the desired length we can generate between 0 and 899,999.
* After this, we can add 100,000 back to the number to ensure a baseline length is maintained.
*
* Note: I am aware that this is overengineered, and that several random integers of amount @length could be used,
* but this is considerably more efficient since there is no iteration involved in the creation of the ID. O(1)
*/
public String generateUserID( String prefix, int length )
{
Random random = new Random();
final int offset = (int) Math.pow( 10, (length-1) ); // Static integer equal to 10^(length-1) lower than length. This will allow for the factor to be consistent.
int intLength = (int) ( Math.pow( 10, length ) ) - offset ; // Integer equal to 10^(length) minus the offset. This creates a ceiling for the ID range.
if ( uuidSet.size() > ( intLength - 1 ) ) { // No idea why I get an error for equals FIX LATER
System.out.println("Too many user IDs delegated for current range, increasing ID range by a factor of 10");
return generateUserID( prefix, length+1 );
/*
* This is essential for eliminating a stack overflow error when the specified range is full. This would be incorrect to catch.
* By incrementing the length value when the ID range is full, roughly 2.1 billion users can be created without running into an overflow error.
*/
}
String uuid = prefix + ( random.nextInt( intLength ) + offset );
/*
* Sets the uid to the prefix, concat. with a random integer of specified length
* Add the offset to a random number, to create a floor to the ID range.
*/
if ( uuidSet.contains( uuid ) )
{
generateUserID( prefix, length ); // If the ID generated is already contained in the hashset, the method should be called again.
}
uuidSet.add( uuid ); // Add the UUID to the hash set so it cannot be returned from this method more than once.
return uuid;
}
/*
* A method to output all user data to a file using a fileDialog to specify file location.
*
* Note: Potentially could implement the HashSet made for GenerateUserID to avoid unnecessary recursion.
*/
public void writeUserData()
{
try {
Frame frame = null; // Initialise null frame
FileDialog fileBox = new FileDialog( frame, "Save", FileDialog.SAVE ); // Initialise file dialog box to save written data.
fileBox.setVisible( true );
PrintWriter writer = new PrintWriter( new File( fileBox.getDirectory() + fileBox.getFile() ) );
for ( LibraryUser user : userList ){
user.writeData( writer );
}
writer.close();
}
catch( IOException e ) { // Catch any IO Exceptions that may occur from improper file selection.
System.err.println( "Caught IOException: " + e.getMessage() + "\nAn I/O Exception has occurred, please check file is readable and correct format." );
}
}
/*
* Prints to the terminal, in a human-readable format, all items in the itemList
*
* Contains a marker at the start and end to visualise in terminal output.
*/
public void printAll()
{
System.out.println("\n\nStart Detail Print");
for( LibraryItem item : itemList )
{
System.out.println("---------------");
item.printDetails();
}
System.out.println("End Detail Print\n");
}
/*
* A method to read all data from files using a fileDialog to specify file location.
* This will create the corresponding objects depending on flags contained in the file
* and populate it's fields.
*
* Default flag value: "book", to support legacy files. This will not interfere with
* files of different flag orders.
*/
public void readData()
{
Frame frame = null; // Initialise a null frame
FileDialog fileBox = new FileDialog( frame, "Open", FileDialog.LOAD ); // Initialise filebox with the null frame pointer
@@ -53,30 +153,33 @@ public class Library
try {
Scanner fileScanner = new Scanner( new File( fileBox.getDirectory() + fileBox.getFile() ) );
String typeFlag = "";
String typeFlag = "book"; // Set a default flag to support legacy files.
while( fileScanner.hasNextLine() ){
String lineItem = fileScanner.nextLine();
//System.out.println( lineItem );
// Ensure no comments or empty lines are included
if ( lineItem.contains( "//" ) || lineItem.trim().isEmpty() ){}
// Check current line is a candidate flag
else if ( lineItem.startsWith("[" ) ) {
if ( lineItem.toLowerCase().contains("book") ) {
if ( lineItem.toLowerCase().contains("book") )
typeFlag = "book";
//System.out.println( "CHANGED FLAG TO READ BOOKS" );
}
else if ( lineItem.toLowerCase().contains("periodical") ) {
else if ( lineItem.toLowerCase().contains("periodical") )
typeFlag = "periodical";
//System.out.println( "CHANGED FLAG TO READ PERIODICALS" );
}
else if ( lineItem.toLowerCase().contains("cd") )
typeFlag = "cd";
else if ( lineItem.toLowerCase().contains("dvd") )
typeFlag = "dvd";
else if ( lineItem.toLowerCase().contains("user") )
typeFlag = "user";
else {
System.out.println( "Flag detected, but no accepted format...\n Cannot store item in Library. Changing Flag to generic and skipping the following: ");
typeFlag = "generic";
}
}
// Could be a switch case to be more efficient
@@ -96,8 +199,29 @@ public class Library
periodical.readItemData( detailScanner );
storeItem( periodical );
}
else if ( typeFlag.equals( "cd" ) ) {
//Process CD Data
Scanner detailScanner = new Scanner ( lineItem ).useDelimiter(",");
LibraryItem cd = new CD();
cd.readItemData( detailScanner );
storeItem( cd );
}
else if ( typeFlag.equals( "dvd" ) ) {
//Process DVD Data
Scanner detailScanner = new Scanner ( lineItem ).useDelimiter(",");
LibraryItem dvd = new DVD();
dvd.readItemData( detailScanner );
storeItem( dvd );
}
else if ( typeFlag.equals( "user" ) ) {
//Process User Data
Scanner detailScanner = new Scanner ( lineItem ).useDelimiter(",");
LibraryUser user = new LibraryUser();
user.readData( detailScanner );
storeUser( user );
}
else if ( typeFlag.equals( "generic" ) ) {
// Output unaccepted lines
// Output unaccepted lines to terminal
System.out.println( lineItem );
}
}