deyanpeev · deyanpeev · Jan 25, 2023 · Jan 25, 2023
diff --git a/Seminar7/code/Server/.idea/.gitignore b/Seminar7/code/Server/.idea/.gitignore
diff --git a/Seminar7/code/Server/.idea/misc.xml b/Seminar7/code/Server/.idea/misc.xml
diff --git a/Seminar7/code/Server/.idea/modules.xml b/Seminar7/code/Server/.idea/modules.xml
diff --git a/Seminar7/code/Server/.idea/vcs.xml b/Seminar7/code/Server/.idea/vcs.xml
diff --git a/Seminar7/code/Server/out/production/Server/ClientResolver.class b/Seminar7/code/Server/out/production/Server/ClientResolver.class
diff --git a/Seminar7/code/Server/out/production/Server/Computer.class b/Seminar7/code/Server/out/production/Server/Computer.class
diff --git a/Seminar7/code/Server/out/production/Server/ComputerBuilder.class b/Seminar7/code/Server/out/production/Server/ComputerBuilder.class
diff --git a/Seminar7/code/Server/out/production/Server/Main.class b/Seminar7/code/Server/out/production/Server/Main.class
diff --git a/Seminar7/code/Server/out/production/Server/ServerHandler.class b/Seminar7/code/Server/out/production/Server/ServerHandler.class
diff --git a/Seminar7/code/Server/out/production/Server/Store.class b/Seminar7/code/Server/out/production/Server/Store.class
diff --git a/Seminar7/code/Server/out/production/Server/StoreSeeder.class b/Seminar7/code/Server/out/production/Server/StoreSeeder.class
diff --git a/Seminar7/code/Server/out/production/Server/StreamCommunicator.class b/Seminar7/code/Server/out/production/Server/StreamCommunicator.class
diff --git a/Seminar7/code/Server/src/ClientResolver.java b/Seminar7/code/Server/src/ClientResolver.java
@@ -0,0 +1,34 @@
+import java.io.PrintStream;
+import java.net.Socket;
+import java.util.Scanner;
+
+public class ClientResolver implements Runnable  {
+    private Socket clientSocket;
+    private Store store;
+
+    public ClientResolver(Socket socket, Store store)
+    {
+        this.clientSocket = socket;
+        this.store = store;
+    }
+
+    public void run()
+    {
+        Scanner in = null;
+        PrintStream out = null;
+        try {
+            in = new Scanner(clientSocket.getInputStream());
+            out = new PrintStream(clientSocket.getOutputStream());
+            StreamCommunicator communicator = new StreamCommunicator(in, out);
+
+            var server = new ServerHandler(communicator, this.store);
+            server.startCommunication();
+        } catch (Exception e) {
+            System.out.println(e.getMessage());
+            System.out.println("Connection closed.");
+        } finally {
+            in.close();
+            out.close();
+        }
+    }
+}
diff --git a/Seminar7/code/Server/src/Computer.java b/Seminar7/code/Server/src/Computer.java
@@ -0,0 +1,76 @@
+import java.time.LocalDate;
+
+public class Computer {
+    private int id;
+    private String brand;
+    private String model;
+    private boolean isUsed;
+    private LocalDate manufacturedDate;
+    private int quantity;
+
+    public Computer() { }
+
+    public Computer(String brand, String model, boolean isUsed, LocalDate manufacturedDate, int quantity) {
+        this.setBrand(brand);
+        this.setModel(model);
+        this.setUsed(isUsed);
+        this.setManufacturedDate(manufacturedDate);
+        this.setQuantity(quantity);
+    }
+
+    public int getId() {
+        return id;
+    }
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getBrand() {
+        return brand;
+    }
+    public void setBrand(String brand) {
+        this.brand = brand;
+    }
+
+    public String getModel() {
+        return model;
+    }
+    public void setModel(String model) {
+        this.model = model;
+    }
+
+    public boolean isUsed() {
+        return isUsed;
+    }
+    public void setUsed(boolean used) {
+        isUsed = used;
+    }
+
+    public LocalDate getManufacturedDate() {
+        return manufacturedDate;
+    }
+    public void setManufacturedDate(LocalDate manufacturedDate) {
+        this.manufacturedDate = manufacturedDate;
+    }
+
+    public int getQuantity() {
+        return quantity;
+    }
+    public void setQuantity(int quantity) {
+        this.quantity = quantity;
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder sb = new StringBuilder();
+        sb.append("Computer: #").append(this.getId()).append("\t")
+                .append(this.getBrand()).append(" ").append(this.getModel()).append("\t")
+                .append("Year of manufacturing: ").append(this.getManufacturedDate().toString()).append("\t")
+                .append("Quantity: ").append(this.getQuantity()).append("\t");
+        if(this.isUsed()) {
+            sb.append("Computer is used").append("\t");
+        }
+
+        return sb.toString();
+    }
+}
diff --git a/Seminar7/code/Server/src/ComputerBuilder.java b/Seminar7/code/Server/src/ComputerBuilder.java
@@ -0,0 +1,14 @@
+import java.time.LocalDate;
+
+public class ComputerBuilder {
+    public static Computer build(StreamCommunicator communicator) {
+        Computer computer = new Computer();
+        computer.setBrand(communicator.communicateMessage("Enter brand:"));
+        computer.setModel(communicator.communicateMessage("Enter model:"));
+        computer.setManufacturedDate(LocalDate.parse(
+                communicator.communicateMessage("Enter date (in format: yyyy-mm-dd):")));
+        computer.setUsed(Boolean.parseBoolean(communicator.communicateMessage("Is used:")));
+        computer.setQuantity(Integer.parseInt(communicator.communicateMessage("Quantity:")));
+        return computer;
+    }
+}
diff --git a/Seminar7/code/Server/src/Main.java b/Seminar7/code/Server/src/Main.java
@@ -0,0 +1,29 @@
+import java.io.IOException;
+import java.net.ServerSocket;
+import java.net.Socket;
+import java.net.SocketException;
+
+public class Main {
+    private static final int SOCKET_PORT = 5038; //Any random free port
+
+    public static void main(String[] args) {
+        ServerSocket server = null;
+        Store store = StoreSeeder.getSeededStore();
+
+        try {
+            server = new ServerSocket(SOCKET_PORT);
+
+            while (true) {
+                Socket client = server.accept();
+                System.out.println("Connection established: " + client.getInetAddress().getHostAddress());
+
+                ClientResolver resolver = new ClientResolver(client, store);
+                new Thread(resolver).start();
+            }
+        } catch (SocketException e) {
+            throw new RuntimeException(e);
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+}
diff --git a/Seminar7/code/Server/src/ServerHandler.java b/Seminar7/code/Server/src/ServerHandler.java
@@ -0,0 +1,45 @@
+import java.io.PrintStream;
+import java.util.Scanner;
+
+public class ServerHandler {
+    private StreamCommunicator communicator;
+    private Store store;
+
+    public ServerHandler(StreamCommunicator communicator, Store store) {
+        this.communicator = communicator;
+        this.store = store;
+    }
+
+    public void startCommunication() {
+        int choice = Integer.parseInt(communicator.communicateMessage("Write 1 for administrator and 2 for client"));
+        switch(choice) {
+            case 1:
+                this.communicateAdmin();
+                break;
+            case 2:
+                this.communicateCustomer();
+                break;
+            default:
+                communicator.communicateMessage("Not an option");
+        }
+    }
+
+    private void communicateAdmin() {
+        communicator.addMessage("Entering a new computer details.");
+        Computer computer = ComputerBuilder.build(communicator);
+        this.store.addComputer(computer);
+    }
+
+    private void communicateCustomer() {
+        communicator.communicateMessage("Buying a computer.",
+                this.store.getAvailableComputers(),
+                "Which computer would you like to buy");
+        int computerId = Integer.parseInt(communicator.communicateMessage());
+        int quantity = Integer.parseInt(communicator.communicateMessage("How many?"));
+        try {
+            store.sellComputers(computerId, quantity);
+        } catch (Exception ex) {
+            communicator.communicateMessage(ex.getMessage());
+        }
+    }
+}
diff --git a/Seminar7/code/Server/src/Store.java b/Seminar7/code/Server/src/Store.java
@@ -0,0 +1,43 @@
+import java.util.*;
+
+public class Store {
+    private List<Computer> availableComputers = Collections.synchronizedList(new ArrayList<>());
+
+    public void addComputer(Computer computer) {
+        computer.setId(this.availableComputers.size());
+        this.availableComputers.add(computer);
+    }
+
+    public String getAvailableComputers() {
+        StringBuffer sb = new StringBuffer();
+        for (var computer : this.availableComputers) {
+            sb.append(computer);
+        }
+
+        return sb.toString();
+    }
+
+    public void sellComputers(int computerId, int desiredQuantity) {
+        synchronized (this.availableComputers) {
+            var computerInStock = this.availableComputers.stream()
+                    .filter(c -> c.getId() == computerId).findFirst();
+
+            if (computerInStock.isEmpty()) {
+                throw new IllegalArgumentException("Computer with id " + computerId + " doesn't exist.");
+            }
+
+            Computer computer = computerInStock.get();
+            int newQuantity = computer.getQuantity() - desiredQuantity;
+            if (newQuantity < 0) {
+                throw new IllegalArgumentException("There are only " + computer.getQuantity() + " computers left."
+                        + " We cannot sell you " + desiredQuantity);
+            }
+
+            if(newQuantity == 0) {
+                this.availableComputers.remove(computer);
+            } else {
+                computer.setQuantity(newQuantity);
+            }
+        }
+    }
+}
diff --git a/Seminar7/code/Server/src/StoreSeeder.java b/Seminar7/code/Server/src/StoreSeeder.java
@@ -0,0 +1,17 @@
+import java.time.LocalDate;
+
+public class StoreSeeder {
+    public static Store getSeededStore() {
+        Store store = new Store();
+        populate(store);
+        return store;
+    }
+
+    private static void populate(Store store) {
+        store.addComputer(new Computer("Lenovo", "T15", false, LocalDate.now(), 5));
+        store.addComputer(new Computer("Asus", "Zenbook",
+                true, LocalDate.of(2020, 10, 1), 2));
+        store.addComputer(new Computer("Apple", "Macbook Pro",
+                false, LocalDate.of(2021, 10, 31), 30));
+    }
+}
diff --git a/Seminar7/code/Server/src/StreamCommunicator.java b/Seminar7/code/Server/src/StreamCommunicator.java
@@ -0,0 +1,32 @@
+import java.io.PrintStream;
+import java.lang.invoke.StringConcatException;
+import java.util.*;
+
+public class StreamCommunicator {
+    private Scanner in;
+    private PrintStream out;
+    private List<String> messages;
+
+    public StreamCommunicator(Scanner in, PrintStream out) {
+      this.in = in;
+      this.out = out;
+      this.messages = new ArrayList<>();
+    }
+
+    public void addMessage(String message) {
+        this.messages.add(message);
+    }
+
+    public String communicateMessage() {
+        var result = this.communicateMessage(this.messages.toArray(String[]::new));
+        this.messages.clear();
+        return result;
+    }
+
+    public String communicateMessage(String ...messsages) {
+        String messageToSend = Arrays.stream(messsages).reduce("",
+                (String total, String current) -> total + current);
+        out.println(messageToSend);
+        return in.nextLine();
+    }
+}