HomeWork 13

src/main/java/ru/otus/java/basic/homeworks/homework13/client/client.java

@@ -0,0 +1,51 @@
+package ru.otus.java.basic.homeworks.homework13.client;
+
+import java.io.BufferedInputStream;
+import java.io.DataInputStream;
+import java.io.IOException;
+import java.io.PrintStream;
+import java.net.Socket;
+import java.util.Scanner;
+
+public class client {
+    private final DataInputStream in;
+    private final PrintStream out;
+
+    public static void main(String[] args) {
+        try(Socket socket = new Socket("localhost", 8888)) {
+            client client = new client(socket);
+            String result = client.read();
+            System.out.print(result);
+            result = client.read();
+            System.out.print(result);
+
+            System.out.print("Введите математическую операцию: ");
+
+            Scanner scanner  = new Scanner(System.in);
+            String userInput = scanner.nextLine();
+            scanner.close();
+
+            client.send(userInput);
+            result = client.read();
+            System.out.println(result);
+        } catch (Exception e) {
+            System.out.println(e.getMessage());
+        }
+
+    }
+
+    public client(Socket socket) throws IOException {
+        in = new DataInputStream(new BufferedInputStream(socket.getInputStream()));
+        out = new PrintStream(socket.getOutputStream());
+    }
+
+    public void send(String message) {
+        out.println(message);
+        out.flush();
+    }
+
+    public String read() throws IOException {
+        return in.readUTF();
+    }
+
+}

src/main/java/ru/otus/java/basic/homeworks/homework13/server/server.java

@@ -0,0 +1,72 @@
+package ru.otus.java.basic.homeworks.homework13.server;
+
+import java.io.BufferedOutputStream;
+import java.io.BufferedReader;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.ServerSocket;
+import java.net.Socket;
+import java.util.Objects;
+
+public class server {
+    public static void main(String[] args) throws IOException {
+        ServerSocket serverSocket = new ServerSocket(8888);
+        Socket client = serverSocket.accept();
+        System.out.println("Client connected");
+        printStartInfo(client);
+        while(processRequest(client)) {}
+    }
+
+    public static void printStartInfo(Socket client) throws IOException {
+        DataOutputStream out = new DataOutputStream(new BufferedOutputStream(client.getOutputStream()));
+        out.writeUTF("available math operations: +,-,*,/ enter exit for exit\n");
+        out.writeUTF("example: 1 + 2\n");
+        out.flush();
+    }
+
+    public static boolean processRequest(Socket client) throws IOException {
+        BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));
+        String userInput = in.readLine();
+        if (Objects.equals(userInput, "exit")) {
+            return false;
+        }
+        System.out.println("Original: " + userInput);
+        String result = makeMath(userInput);
+        System.out.println("Result: " + result);
+        DataOutputStream out = new DataOutputStream(new BufferedOutputStream(client.getOutputStream()));
+        out.writeUTF(result);
+        out.flush();
+        return true;
+    }
+
+    private static String makeMath(String expression) {
+        String[] parts = expression.split(" ");
+        if (parts.length != 3) {
+            return "input error\n";
+        }
+        try {
+            int n1 = Integer.parseInt(parts[0]);
+            String operation = parts[1];
+            int n2 = Integer.parseInt(parts[2]);
+
+            if (Objects.equals(operation, "+")) {
+                return (n1 + n2) + "\n";
+            }
+            if (Objects.equals(operation, "-")) {
+                return (n1 - n2) + "\n";
+            }
+            if (Objects.equals(operation, "*")) {
+                return (n1 * n2) + "\n";
+            }
+            if (Objects.equals(operation, "/")) {
+                return (n1 / n2) + "\n";
+            }
+            return "input error\n";
+        } catch (NumberFormatException e) {
+            System.out.println(e.getMessage());
+        }
+
+        return "input error\n";
+    }
+}