update,

2025-01-31 19:15:17 +08:00
parent 09adae8c8e
commit 6c60a73f30
1546 changed files with 286918 additions and 0 deletions
--- a/_resources/it114105/itp4507/Assignment/19-20/src/Assignment.java
+++ b/_resources/it114105/itp4507/Assignment/19-20/src/Assignment.java
@@ -0,0 +1,61 @@
+
+import java.util.ArrayList;
+import java.util.Scanner;
+
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+/**
+ *
+ * @author jerrykwok
+ */
+public class Assignment {
+    private static Scanner input;
+    private static ArrayList<CoffeeProduct> productList;
+    private static StateManager stateMang;
+    private static CommandHandler ch;
+
+    public static void main(String[] args) {
+        input = new Scanner(System.in);
+        productList = createList();
+        stateMang = createStateManager();
+        ch = createCommand();
+        run();
+    }
+
+    public static void run(){
+      while (true) {
+          System.out.println("Coffee Inventory Management System");
+          ch.printCommandList();
+          String cmd = input.nextLine();
+          boolean result = ch.run(cmd);
+          if (!result) {
+              System.out.println("No Command Match");
+          }
+          System.out.println("");
+      }
+    }
+
+    public static CommandHandler createCommand() {
+        CommandHandler ch = new CommandHandler(stateMang);
+        ch.regCommand("a", new AddProductCommandFactory(input, productList));
+        ch.regCommand("v", new ViewProductCommandFactory(input, productList));
+        ch.regCommand("c", new CollectProductCommandFactory(input, productList, stateMang));
+        ch.regCommand("s", new SendCoffeeProductCommandFactory(input, productList, stateMang));
+        ch.regCommand("u", new UndoLastCommandFactory(stateMang));
+        ch.regCommand("r", new RedoLastCommandFactory(stateMang));
+        ch.regCommand("sl", new ViewUndoRedoListCommandFactory(stateMang));
+        ch.regCommand("x", new ExitCommandFactory());
+        return ch;
+    }
+
+    public static StateManager createStateManager() {
+        return new StateManager();
+    }
+
+    private static ArrayList<CoffeeProduct> createList(){
+      return new ArrayList<CoffeeProduct>();
+    }
+}
--- a/_resources/it114105/itp4507/Assignment/19-20/src/Caretaker.java
+++ b/_resources/it114105/itp4507/Assignment/19-20/src/Caretaker.java
@@ -0,0 +1,51 @@
+
+import java.util.Stack;
+
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+/**
+ *
+ * @author jerrykwok
+ */
+public class Caretaker {
+
+    private Stack<CoffeeProductMemento> undoList;
+    private Stack<CoffeeProductMemento> redoList;
+
+    public Caretaker() {
+        undoList = new Stack();
+        redoList = new Stack();
+    }
+
+    public void saveCoffeeProduct(CoffeeProductMemento xcoffeeProd) {
+        redoList.clear();
+        undoList.push(xcoffeeProd);
+    }
+
+    public void undo() {
+        if (undoList.isEmpty()) {
+            System.out.println("UndoList is Empty");
+            return;
+        }
+        CoffeeProductMemento obj =  undoList.pop();
+
+        redoList.push(obj.getOrig().saveMemento());
+        
+        obj.restore();
+    }
+
+    public void redo() {
+        if (redoList.isEmpty()) {
+            System.out.println("RedoList is Empty");
+            return;
+        }
+        CoffeeProductMemento obj = redoList.pop();
+        undoList.push(obj.getOrig().saveMemento());
+        obj.restore();
+
+    }
+
+}
--- a/_resources/it114105/itp4507/Assignment/19-20/src/CoffeeCandy.java
+++ b/_resources/it114105/itp4507/Assignment/19-20/src/CoffeeCandy.java
@@ -0,0 +1,51 @@
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+
+/**
+ *
+ * @author jerrykwok
+ */
+public class CoffeeCandy extends CoffeeProduct {
+
+    private int noOfCandy;
+    private int caloriesPerCandy;
+
+    public CoffeeCandy(String name, int productID, int noOfCandy, int caloriesPerCandy) {
+        super(name, productID);
+        this.noOfCandy = noOfCandy;
+        this.caloriesPerCandy = caloriesPerCandy;
+    }
+
+    public int getNoOfCandy() {
+        return noOfCandy;
+    }
+
+    public int getCaloriesPerCandy() {
+        return caloriesPerCandy;
+    }
+
+    public void setNoOfCandy(int noOfCandy) {
+        this.noOfCandy = noOfCandy;
+    }
+
+    public void setCaloriesPerCandy(int caloriesPerCandy) {
+        this.caloriesPerCandy = caloriesPerCandy;
+    }
+
+    @Override
+    public String toString() {
+        return super.toString() + "Number of candies per package: " + getNoOfCandy() + "\n" + "Calories Per candy: " + getCaloriesPerCandy();
+    }
+
+    public String printList() {
+        return super.printList() +"\t"+ getQty()+ "\t\t" + getNoOfCandy() + " candy per package (" + getCaloriesPerCandy() + " calories each)";
+    }
+    
+    public CoffeeProductMemento saveMemento(){
+        return new CoffeeCandyMemento(this);
+    }
+
+}
--- a/_resources/it114105/itp4507/Assignment/19-20/src/CoffeeProduct.java
+++ b/_resources/it114105/itp4507/Assignment/19-20/src/CoffeeProduct.java
@@ -0,0 +1,57 @@
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+
+/**
+ *
+ * @author jerrykwok
+ */
+public abstract class CoffeeProduct {
+
+    private String name;
+    private int productID;
+    private int qty;
+
+    public CoffeeProduct(String name, int productID) {
+        this.name = name;
+        this.productID = productID;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public int getProductID() {
+        return productID;
+    }
+
+    public int getQty() {
+        return qty;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public void setProductID(int productID) {
+        this.productID = productID;
+    }
+
+    public void setQty(int qty) {
+        this.qty = qty;
+    }
+
+    @Override
+    public String toString() {
+        return "ID: " + getProductID() + "\nName: " + getName() + "\nQuantity: " + getQty() + "\n";
+    }
+
+    public String printList() {
+        return getProductID() + "\t" + getName() + "\t" ;
+    }
+    
+    public abstract CoffeeProductMemento saveMemento();
+
+}
--- a/_resources/it114105/itp4507/Assignment/19-20/src/CoffeeProductMemento.java
+++ b/_resources/it114105/itp4507/Assignment/19-20/src/CoffeeProductMemento.java
@@ -0,0 +1,75 @@
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+
+/**
+ *
+ * @author jerrykwok
+ */
+public interface CoffeeProductMemento {
+    public CoffeeProduct getOrig();
+    public void restore();
+}
+
+class CoffeeCandyMemento implements CoffeeProductMemento{
+    private int noOfCandy;
+    private int caloriesPerCandy;
+    private int qty;
+    private CoffeeCandy mcoffeeCandy;
+
+    public CoffeeCandyMemento(CoffeeCandy mcoffeeCandy) {
+        this.noOfCandy = mcoffeeCandy.getNoOfCandy();
+        this.caloriesPerCandy = mcoffeeCandy.getCaloriesPerCandy();
+        this.qty = mcoffeeCandy.getQty();
+        this.mcoffeeCandy = mcoffeeCandy;
+    }
+
+    
+    @Override
+    public CoffeeProduct getOrig() {
+        return mcoffeeCandy;
+    }
+
+    @Override
+    public void restore() {
+        mcoffeeCandy.setCaloriesPerCandy(caloriesPerCandy);
+        mcoffeeCandy.setNoOfCandy(noOfCandy);
+        mcoffeeCandy.setQty(qty);
+    }
+
+    
+    public String print() {
+        return "CoffeeCandyMemento{" + "noOfCandy=" + noOfCandy + ", caloriesPerCandy=" + caloriesPerCandy + ", mcoffeeCandy=" + mcoffeeCandy + '}';
+    }
+    
+
+}
+
+class CoffeeProwderMemento implements CoffeeProductMemento{
+
+    private double wegiht;
+    private int qty;
+    private CoffeeProwder mcoffeeProwder;
+
+    public CoffeeProwderMemento(CoffeeProwder mcoffeeProwder) {
+        this.wegiht = mcoffeeProwder.getWegiht();
+        this.qty = mcoffeeProwder.getQty();
+        this.mcoffeeProwder = mcoffeeProwder;
+        
+    }
+            
+    
+    @Override
+    public CoffeeProduct getOrig() {
+        return mcoffeeProwder;
+    }
+
+    @Override
+    public void restore() {
+        mcoffeeProwder.setWegiht(this.wegiht);
+        mcoffeeProwder.setQty(qty);
+    }
+ 
+}
--- a/_resources/it114105/itp4507/Assignment/19-20/src/CoffeeProwder.java
+++ b/_resources/it114105/itp4507/Assignment/19-20/src/CoffeeProwder.java
@@ -0,0 +1,41 @@
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+
+/**
+ *
+ * @author jerrykwok
+ */
+public class CoffeeProwder extends CoffeeProduct {
+
+    private double wegiht;
+
+    public CoffeeProwder(String name, int productID, double wegiht) {
+        super(name, productID);
+        this.wegiht = wegiht;
+    }
+
+    public double getWegiht() {
+        return wegiht;
+    }
+
+    public void setWegiht(double wegiht) {
+        this.wegiht = wegiht;
+    }
+
+
+    public String toString() {
+        return super.toString() + "Wegiht: " + getWegiht() + "\n";
+    }
+
+    public String printList() {
+        return super.printList() + "\t\t" + getQty() + "\t\t" + (int)(getWegiht()) + "g";
+    }
+    
+    public CoffeeProductMemento saveMemento(){
+        return new CoffeeProwderMemento(this);
+    }
+
+}
--- a/_resources/it114105/itp4507/Assignment/19-20/src/Command.java
+++ b/_resources/it114105/itp4507/Assignment/19-20/src/Command.java
@@ -0,0 +1,423 @@
+
+import java.util.ArrayList;
+import java.util.Scanner;
+import java.util.Stack;
+
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+/**
+ *
+ * @author jerrykwok
+ */
+public abstract class Command {
+
+    public abstract boolean execute();
+}
+
+interface UndoAllowCommand {
+
+    public void redo();
+    public void undo();
+}
+
+class AddProductCommand extends Command implements UndoAllowCommand {
+
+    private ArrayList productList;
+    private Scanner input;
+    CoffeeProduct coffeeProduct;
+    
+
+    public AddProductCommand(Scanner input, ArrayList productList) {
+        this.input = input;
+        this.productList = productList;
+    }
+
+    @Override
+    public boolean execute() {
+        System.out.println("Enter Coffee type (cc=Coffee Candy/cp=Coffee Powder):");
+        String type = input.nextLine();
+        switch (type) {
+            case "cc":
+
+                System.out.println("Enter product id, name, number of candy and calories per candy:");
+                String ccValue = input.nextLine();
+                String[] ccParameters = ccValue.split(", ");
+                if(ccParameters.length==1)
+                    ccParameters = ccValue.split(",");
+                if (ccParameters.length != 4) {
+                    System.out.println("Invalid parameter length");
+                    return false;
+                }
+
+                try {
+                    System.out.println();
+                    int productId = Integer.parseInt(ccParameters[0]);
+                    String name = ccParameters[1];
+                    int noOfCandy = Integer.parseInt(ccParameters[2]);
+                    int caloriesPerCandy = Integer.parseInt(ccParameters[3]);
+                    if (checkProducrID(productList, productId)) {
+                        System.out.println("The id: " + productId + "is already exist");
+                        return false;
+                    }
+                    coffeeProduct = creatCoffeeProduct(name, productId, noOfCandy, caloriesPerCandy);
+                } catch (NumberFormatException e) {
+                    System.out.println("Invalid parameter: productID, Number of candy and Calories must be Integer");
+                    return false;
+                }
+
+                break;
+            case "cp":
+                System.out.println("Enter product Id , name and weight(g):");
+                String cpValue = input.nextLine();
+                String[] cpParameters = cpValue.split(", ");
+                if(cpParameters.length==1)
+                    cpParameters = cpValue.split(",");
+                if (cpParameters.length != 3) {
+                    System.out.println("Invalid parameter length");
+                    return false;
+                }
+                try {
+                    int productId = Integer.parseInt(cpParameters[0]);
+                    String name = cpParameters[1];
+                    int wegiht = Integer.parseInt(cpParameters[2]);
+                    if (checkProducrID(productList, productId)) {
+                        System.out.println("The id: " + productId + "is already exist");
+                        return false;
+                    }
+                    coffeeProduct = creatCoffeeProduct(name, productId, wegiht);
+                } catch (NumberFormatException e) {
+                    System.out.println("Invalid parameter: productID, Number of candy and Calories must be Integer");
+                    return false;
+                }
+                break;
+            default:
+                System.out.println("Invalid Coffee Prodcut Type");
+                return false;
+        }
+        productList.add(coffeeProduct);
+        System.out.println("New product record created.\n");
+        return true;
+
+    }
+
+    @Override
+    public void redo() {
+        
+        productList.add(coffeeProduct);
+    }
+
+    @Override
+    public void undo() {
+        productList.remove(coffeeProduct);
+    }
+    
+
+    public static CoffeeProduct creatCoffeeProduct(String name, int productID, int noOfCandy, int caloriesPerCandy) {
+        return new CoffeeCandy(name, productID, noOfCandy, caloriesPerCandy);
+    }
+
+    public static CoffeeProduct creatCoffeeProduct(String name, int productID, int wegiht) {
+        return new CoffeeProwder(name, productID, wegiht);
+    }
+
+    public boolean checkProducrID(ArrayList<CoffeeProduct> productList, int id) {
+        boolean invalid = false;
+        for (CoffeeProduct product : productList) {
+            if (product.getProductID() == id) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return "Add " + coffeeProduct.getProductID() +" " + coffeeProduct.getName();
+    }
+    
+    
+    
+
+}
+
+class ViewProductCommand extends Command {
+
+    private ArrayList<CoffeeProduct> productList;
+    private Scanner input;
+
+    public ViewProductCommand(Scanner input, ArrayList productList) {
+        this.input = input;
+        this.productList = productList;
+    }
+
+    @Override
+    public boolean execute() {
+        System.out.println("Enter product Id. (* to show all):");
+        String id = input.nextLine();
+        System.out.println("");
+        if (id.equals("*")) {
+            System.out.println("Coffee Product information");
+            System.out.println("ID\tName\t\t\t\tQuantity\tOther Info");
+            for (CoffeeProduct product : productList) {
+                System.out.println(product.printList());
+            }
+        } else {
+
+            try {
+                int productId = Integer.parseInt(id);
+                System.out.println("Product information");
+                boolean succe = false;
+                for (CoffeeProduct product : productList) {
+                    if (product.getProductID() == productId) {
+                        System.out.println(product);
+                        succe = true;
+                        break;
+                    }
+                }
+                if (!succe) {
+                    System.out.println("Not this ID: " + productId + " Product");
+                }
+            } catch (NumberFormatException e) {
+                System.out.println("Invalid id, id must be integer only");
+                return false;
+            }
+
+        }
+        return true;
+    }
+}
+
+class CollectProductCommand extends Command implements UndoAllowCommand {
+
+    private ArrayList<CoffeeProduct> productList;
+    private Scanner input;
+    private StateManager state;
+    private CoffeeProduct coffeeProduct;
+    private int productQty;
+
+    public CollectProductCommand(Scanner input, ArrayList<CoffeeProduct> productList, StateManager state) {
+        this.productList = productList;
+        this.input = input;
+        this.state = state;
+    }
+
+    @Override
+    public boolean execute() {
+        int productId;
+        
+        try {
+            System.out.println("Enter product id:");
+            String id = input.nextLine();
+            productId = Integer.parseInt(id);
+
+        } catch (NumberFormatException e) {
+            System.out.println("Invalid id, id must be integer only");
+            return false;
+        }
+        try {
+            System.out.println("Quantity to receive:");
+            String qty = input.nextLine();
+            productQty = Integer.parseInt(qty);
+        } catch (NumberFormatException e) {
+            System.out.println("Invalid Quantity, Quantity must be integer only");
+            return false;
+        }
+        boolean invalid = true;
+        for (CoffeeProduct product : productList) {
+            if (product.getProductID() == productId) {
+                coffeeProduct = product;
+                state.getCaretaker().saveCoffeeProduct(product.saveMemento());
+                product.setQty(product.getQty() + productQty);
+                System.out.println("Received " + productQty + " packs of " + product.getName() + ". Current quantity is " + product.getQty() + ".");
+                invalid = false;
+                break;
+            }
+        }
+        if (invalid) {
+            System.out.println("No such Coffee Product");
+            return false;
+        }
+        return true;
+    }
+
+    @Override
+    public void redo() {
+        state.getCaretaker().redo();
+    }
+
+    @Override
+    public void undo() {
+        state.getCaretaker().undo();
+    }
+    
+    public String toString(){
+        return "Received " + productQty + " " +coffeeProduct.getName() + " ("+coffeeProduct.getProductID()+")";
+    }
+}
+
+class SendCoffeeProductCommand extends Command implements UndoAllowCommand {
+
+    private ArrayList<CoffeeProduct> productList;
+    private Scanner input;
+    private StateManager state;
+    private CoffeeProduct coffeeProduct;
+    private int shipQty;
+
+    public SendCoffeeProductCommand(Scanner input, ArrayList<CoffeeProduct> productList, StateManager state) {
+        this.productList = productList;
+        this.input = input;
+        this.state = state;
+    }
+
+    @Override
+    public boolean execute() {
+        int productId;
+        
+        try {
+            System.out.println("Enter product id:");
+            String id = input.nextLine();
+            productId = Integer.parseInt(id);
+
+        } catch (NumberFormatException e) {
+            System.out.println("Invalid id, id must be integer only");
+            return false;
+        }
+        try {
+            System.out.println("Quantity to ship:");
+            String qty = input.nextLine();
+            shipQty = Integer.parseInt(qty);
+        } catch (NumberFormatException e) {
+            System.out.println("Invalid Quantity, Quantity must be integer only");
+            return false;
+        }
+        boolean succe = true;
+        for (CoffeeProduct product : productList) {
+            if (product.getProductID() == productId) {
+                if ((product.getQty() - shipQty) < 0) {
+                    System.out.println("Invalid quantity (current balance is less than required quantity). Try again!!!");
+                    return false;
+                }
+                coffeeProduct = product;
+                state.getCaretaker().saveCoffeeProduct(product.saveMemento());
+                product.setQty(product.getQty() - shipQty);
+                System.out.println("Shipped " + shipQty +" packs of Premium Coffee Candy. Current quantity is "+ product.getQty()+".");
+                succe = false;
+                break;
+            }
+        }
+        if (succe) {
+            System.out.println("No such Coffee Product");
+            return false;
+        }
+        return true;
+    }
+
+    @Override
+    public void redo() {
+        state.getCaretaker().redo();
+    }
+
+    @Override
+    public void undo() {
+        state.getCaretaker().undo();
+    }
+    
+    public String toString(){
+        return "Shipped " + shipQty + " " + coffeeProduct.getName() + " (" + coffeeProduct.getProductID()+ ")";
+    }
+
+}
+
+class UndoLastCommand extends Command {
+
+    private StateManager state;
+
+    public UndoLastCommand(StateManager state) {
+        this.state = state;
+    }
+
+    @Override
+    public boolean execute() {
+        if (state.getUndoList().isEmpty()) {
+            System.out.println("Nothing to undo");
+        } else {
+            Stack<UndoAllowCommand> UndoList = state.getUndoList();
+            UndoAllowCommand undoCmd = UndoList.pop();
+            state.getRedoList().push(undoCmd);
+            undoCmd.undo();
+            System.out.println("undo completed.");
+
+        }
+        return true;
+    }
+
+}
+
+class RedoLastCommand extends Command {
+
+    private StateManager state;
+
+    public RedoLastCommand(StateManager state) {
+        this.state = state;
+    }
+
+    @Override
+    public boolean execute() {
+        if (state.getRedoList().isEmpty()) {
+            System.out.println("Nothing to Redo");
+        } else {
+            Stack<UndoAllowCommand> redoList = state.getRedoList();
+            UndoAllowCommand redoCmd = redoList.pop();
+            state.getUndoList().push(redoCmd);
+            redoCmd.redo();
+            System.out.println("Redo completed.");
+        }
+        return true;
+    }        
+    
+    
+}
+
+class ViewUndoRedoListCommand extends Command {
+
+    private StateManager state;
+
+    public ViewUndoRedoListCommand(StateManager state) {
+        this.state = state;
+    }
+
+    @Override
+    public boolean execute() {
+        System.out.println("Undo List:");
+        if (state.getUndoList().isEmpty()) {
+            System.out.println("Empty");
+        } else {
+            state.getUndoList().forEach(System.out::println);
+        }
+        System.out.println();
+
+        System.out.println("Redo List:");
+        if (state.getRedoList().isEmpty()) {
+            System.out.println("Empty");
+        } else {
+            state.getRedoList().forEach(System.out::println);
+        }
+        return true;
+
+    }
+
+}
+
+class ExitCommand extends Command {
+
+    @Override
+    public boolean execute() {
+        System.out.println("Thanks for using Coffee Inventory Management System!!");
+        System.exit(0);
+        return true;
+    }
+
+}
--- a/_resources/it114105/itp4507/Assignment/19-20/src/CommandFactory.java
+++ b/_resources/it114105/itp4507/Assignment/19-20/src/CommandFactory.java
@@ -0,0 +1,181 @@
+
+import java.util.ArrayList;
+import java.util.Scanner;
+
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+/**
+ *
+ * @author jerrykwok
+ */
+public interface CommandFactory {
+
+    public String getCommandName();
+
+    public Command createCommand();
+}
+
+class AddProductCommandFactory implements CommandFactory {
+
+    private Scanner sc;
+    private ArrayList productList;
+
+    public AddProductCommandFactory(Scanner sc, ArrayList productList) {
+        this.sc = sc;
+        this.productList = productList;
+    }
+
+    public String getCommandName() {
+        return "add product, ";
+    }
+
+    public Command createCommand() {
+        return new AddProductCommand(sc, productList);
+    }
+}
+
+class ViewProductCommandFactory implements CommandFactory {
+
+    private Scanner sc;
+    private ArrayList productList;
+
+    public ViewProductCommandFactory(Scanner sc, ArrayList productList) {
+        this.sc = sc;
+        this.productList = productList;
+    }
+
+    @Override
+    public String getCommandName() {
+        return "view products, ";
+    }
+
+    @Override
+    public Command createCommand() {
+        return new ViewProductCommand(sc, productList);
+    }
+
+}
+
+class CollectProductCommandFactory implements CommandFactory {
+
+    private Scanner sc;
+    private ArrayList productList;
+    private StateManager state;
+
+    public CollectProductCommandFactory(Scanner sc, ArrayList productList, StateManager state) {
+        this.sc = sc;
+        this.productList = productList;
+        this.state = state;
+    }
+
+    @Override
+    public String getCommandName() {
+        return "collect product, ";
+    }
+
+    @Override
+    public Command createCommand() {
+        return new CollectProductCommand(sc, productList, state);
+    }
+
+}
+
+class SendCoffeeProductCommandFactory implements CommandFactory {
+
+    private Scanner sc;
+    private ArrayList productList;
+    private StateManager state;
+
+    public SendCoffeeProductCommandFactory(Scanner sc, ArrayList productList, StateManager state) {
+        this.sc = sc;
+        this.productList = productList;
+        this.state = state;
+    }
+
+    @Override
+    public String getCommandName() {
+        return "ship product, \n";
+    }
+
+    @Override
+    public Command createCommand() {
+        return new SendCoffeeProductCommand(sc, productList, state);
+    }
+}
+
+class UndoLastCommandFactory implements CommandFactory {
+
+    private StateManager state;
+
+    public UndoLastCommandFactory(StateManager state) {
+        this.state = state;
+    }
+
+    @Override
+    public String getCommandName() {
+        return "undo, ";
+    }
+
+    @Override
+    public Command createCommand() {
+        return new UndoLastCommand(state);
+    }
+
+}
+
+class ViewUndoRedoListCommandFactory implements CommandFactory {
+
+    private StateManager state;
+
+    public ViewUndoRedoListCommandFactory(StateManager state) {
+        this.state = state;
+    }
+
+    @Override
+    public String getCommandName() {
+        return "show list undo/redo, ";
+    }
+
+    @Override
+    public Command createCommand() {
+        return new ViewUndoRedoListCommand(state);
+
+    }
+}
+
+class RedoLastCommandFactory implements CommandFactory {
+
+    private StateManager state;
+
+    public RedoLastCommandFactory(StateManager state) {
+        this.state = state;
+    }
+
+    @Override
+    public String getCommandName() {
+        return "redo, ";
+    }
+
+    @Override
+    public Command createCommand() {
+        return new RedoLastCommand(state);
+
+    }
+}
+
+class ExitCommandFactory implements CommandFactory {
+
+    @Override
+    public String getCommandName() {
+        return "exit system";
+    }
+
+    @Override
+    public Command createCommand() {
+        return new ExitCommand();
+    }
+
+}
--- a/_resources/it114105/itp4507/Assignment/19-20/src/CommandHandler.java
+++ b/_resources/it114105/itp4507/Assignment/19-20/src/CommandHandler.java
@@ -0,0 +1,59 @@
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Scanner;
+
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+/**
+ *
+ * @author jerrykwok
+ */
+public class CommandHandler {
+
+    private LinkedHashMap<String, CommandFactory> mapCmds;
+    private StateManager state;
+
+    public CommandHandler(StateManager state) {
+        this.mapCmds = new LinkedHashMap<String, CommandFactory>();
+        this.state = state;
+    }
+
+    public void regCommand(String key, CommandFactory cmdFactory) {
+        mapCmds.put(key, cmdFactory);
+    }
+
+    public void printCommandList() {
+        System.out.print("Please enter command: [");
+        System.out.print(String.join(" | ", mapCmds.keySet()));
+        System.out.println("]");
+        for (Map.Entry<String, CommandFactory> mapCmd : mapCmds.entrySet()) {
+            System.out.print(mapCmd.getKey() + " = " + mapCmd.getValue().getCommandName());
+        }
+        System.out.println("\n");
+    }
+
+    public boolean run(String cmd) {
+        CommandFactory commandFactory = mapCmds.get(cmd);
+        if (commandFactory != null) {
+            Command command = commandFactory.createCommand();
+            boolean result = command.execute();
+            if (result) {
+                switch (cmd) {
+                    case "a":
+                    case "c":
+                    case "s":
+                        state.getUndoList().add(command);
+                        state.getRedoList().clear();
+                }
+            }
+            return true;
+        }
+
+        return false;
+    }
+
+}
--- a/_resources/it114105/itp4507/Assignment/19-20/src/StateManager.java
+++ b/_resources/it114105/itp4507/Assignment/19-20/src/StateManager.java
@@ -0,0 +1,36 @@
+
+import java.util.Stack;
+
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+
+/**
+ *
+ * @author jerrykwok
+ */
+public class StateManager {
+    private Stack redoList;
+    private Stack undoList;
+    private Caretaker caretaker;
+    
+    
+    public StateManager() {
+        undoList = new Stack<>();
+        redoList = new Stack<>();
+        caretaker = new Caretaker();
+    }
+    
+    public Caretaker getCaretaker(){
+        return caretaker;
+    }
+    public Stack getUndoList() {
+        return undoList;
+    }
+
+    public Stack getRedoList() {
+        return redoList;
+    }
+}