[TOREVIEW] Client-server Calc

.gitignore

@@ -9,3 +9,7 @@ buildNumber.properties
 .mvn/timing.properties
 # https://github.com/takari/maven-wrapper#usage-without-binary-jar
 .mvn/wrapper/maven-wrapper.jar
+alfavre-alfavre/client/.idea
+alfavre-alfavre/client/out
+alfavre-alfavre/server/.idea
+alfavre-alfavre/server/out

alfavre-alfavre/PROTOCOL.md

@@ -0,0 +1,88 @@
+# Calculator Protocol
+## Authors Alban Favre and Alban Favre
+This is a small server-client application: the client sends an arithmetical instruction like ADD 1 1, the server does the calculation, and sends the result back.
+
+### What transport protocol do we use?
+
+TCP
+
+### How does the client find the server (addresses and ports)?
+
+With it's ip address (or 127.0.0.1 if it's on localhost) and port 2020 (that's this year).
+
+### Who speaks first?
+
+the client send the meeting message (START).
+
+### What is the sequence of messages exchanged by the client and the server? (flow)
+the protocol is quite simple:
+
+- client sends start, indicating it's ready to work
+
+- server answers OK
+
+- client sends operator
+
+- server sends ok or nok (nok is not ok)
+
+- client sends lefthand value
+
+- server sends ok or nok
+
+- client sends righthand value
+
+- server sends ok or nok
+
+- server sends result
+
+- client sends if it want to do another operation (nok if it wants to, ok is ok for leaving)
+
+- client stops if ok, do another round if ok
+
+### What happens when a message is received from the other party? (semantics)
+
+the server does the calculation (and the verification, even if it's useless).
+
+the client checks that the value are correct, then sends them to the server for calculation, then it displays the answer.
+
+### What is the syntax of the messages? How we generate and parse them? (syntax)
+
+the parsing of double is done with methods from java.util.Scanner and with Double.parseDouble(Double_that_became_a_string_for_the_writer);
+
+the string signals are shared, they are found in the Protocol class
+
+### Who closes the connection and when?
+
+the client can close it's connection: when asked to do another operation, and no is choosen, the server sends an OK which means that the client is ok to be disconnected.
+
+the server is never closed, as another client might emerge and ask something
+
+### Notes
+
+protocol: 
+```java
+public class Protocol {
+
+    public static final int CALC_DEFAULT_PORT = 2020;
+
+    public static final String EOL = "\n";
+    public static final String ADD = "ADD";
+    public static final String SUB = "SUB";
+    public static final String MUL = "MUL";
+    public static final String DIV = "DIV";
+    public static final String OK = "OK";
+    public static final String NOK = "NOT OK";
+    public static final String START = "START";
+
+    public static final String OP[]={ADD,SUB,MUL,DIV};
+
+}
+```
+
+0/0 throws an error (not X/0 as this has at least some sense), this is a choice, as NaN is used to check if the lefthand and righthand are correctly initialized
+
+the input verification is done in both the client and server for the time being ( making the server one redundant)
+
+I don't know how to use maven, therefore there is no pom.xml file
+
+I don't know how to make a shared library out of Protocol.java for both the server and client

alfavre-alfavre/client/client.iml

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+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

alfavre-alfavre/client/src/main/java/ch/heigvd/res/App.java

@@ -0,0 +1,19 @@
+package main.java.ch.heigvd.res;
+
+import java.io.IOException;
+import java.net.InetAddress;
+
+
+public class App {
+
+    /**
+     *
+     * @param args the command line arguments
+     */
+    public static void main(String[] args) throws IOException {
+        Client client = new Client(InetAddress.getLocalHost());
+        client.start();
+
+    }
+
+}

alfavre-alfavre/client/src/main/java/ch/heigvd/res/Client.java

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+package main.java.ch.heigvd.res;
+
+
+import java.io.*;
+import java.net.InetAddress;
+import java.net.Socket;
+import java.nio.charset.StandardCharsets;
+import java.util.Scanner;
+
+
+public class Client {
+
+
+    private Socket serverSocket;
+    private BufferedReader reader;
+    private BufferedWriter writer;
+    private final InetAddress host;
+    private double leftHand;
+    private double rightHand;
+    private String op;
+    private OutputStream out;
+    private InputStream in;
+
+
+    /**
+     * constructor
+     * @param host
+     */
+    public Client(InetAddress host) {
+        this.host = host;
+    }
+
+    private static boolean opControl(String op){
+        for(String s:Protocol.OP){
+            if(op.equals(s)){
+                return true;
+            }
+        }
+        return false;
+    }
+
+
+    private void fillValue(){
+        boolean isReading;
+
+        do {
+            System.out.println("Instruction (EX: ADD 1 1): ");
+            System.out.println("ADD SUB MUL DIV only");
+            System.out.println("All extraneous token will be ignored");
+            System.out.println("For some reason, you might have to use 1,2 instead of 1.2");
+            Scanner scanner = new Scanner(System.in);
+
+            try {
+                op = scanner.next();
+
+                if(!opControl(op)){
+                    //je devrait laisser ca au serveur
+                    throw new RuntimeException("Incorrect operand");
+                }
+
+                try {
+                    leftHand = scanner.nextDouble();
+                } catch (Throwable e){
+                    throw new RuntimeException("Incorrect lefthand type: "+e);
+                }
+
+                try {
+                    rightHand = scanner.nextDouble();
+                } catch (Throwable e){
+                    throw new RuntimeException("Incorrect righthand type: "+e);
+                }
+
+                /*if(!scanner.hasNext()){
+                    throw new RuntimeException("Too many arguments");
+                }
+                // THIS DOESN'T WORK
+                */
+
+                isReading=false;
+
+            } catch (Throwable e) {
+                isReading=true;
+                System.out.println("scanner failure type: " + e);
+            }
+
+        }while (isReading);
+
+
+    }
+
+    private void meeting() throws IOException {
+        writer.write(Protocol.START + Protocol.EOL);
+        writer.flush();
+
+        if (!reader.readLine().equals(Protocol.OK)) {
+            throw new IOException("Failed meeting");
+        }
+        System.out.println("Connection successful!");
+    }
+
+    private void communication() throws IOException {
+
+        writer.write(op + Protocol.EOL);
+        writer.flush();
+
+        if (!reader.readLine().equals(Protocol.OK)) {
+            throw new IOException("failed op");
+        }
+
+        writer.write(leftHand + Protocol.EOL);
+        writer.flush();
+
+        if (!reader.readLine().equals(Protocol.OK)) {
+            throw new IOException("failed lefthand");
+        }
+
+        writer.write(rightHand + Protocol.EOL);
+        writer.flush();
+
+        if (!reader.readLine().equals(Protocol.OK)) {
+            throw new IOException("failed righthand");
+        }
+
+        String result = reader.readLine();
+        if (result.equals(Protocol.NOK)) {
+            throw new IOException("failed calculation");
+        }
+
+        System.out.println("the result is: " + result);
+    }
+
+    private boolean nextCalc() throws IOException {
+        String again;
+        System.out.println("Do you want to do another calculation?\n0 yes\n1 no");
+        Scanner s = new Scanner(System.in);
+
+        if (s.nextInt() == 0) {
+            again = Protocol.NOK;
+
+        } else {
+            System.out.println("Actually, we don't care if you entered 1, if it's not 0 then it's no");
+            again = Protocol.OK;
+
+        }
+        writer.write(again + Protocol.EOL);
+        writer.flush();
+        return (again.equals(Protocol.NOK));
+    }
+    /**
+     * run?
+     * @throws IOException
+     */
+    public void start() throws IOException {
+
+
+        try {
+            serverSocket = new Socket(host, Protocol.CALC_DEFAULT_PORT);
+
+            out = serverSocket.getOutputStream();
+            in = serverSocket.getInputStream();
+
+            writer = new BufferedWriter(new OutputStreamWriter(out, StandardCharsets.UTF_8));
+            reader = new BufferedReader(new InputStreamReader(in, StandardCharsets.UTF_8));
+
+            boolean isRunning=true;
+
+            while(isRunning) {
+
+                meeting();
+
+                fillValue();
+
+                communication();
+
+                isRunning=nextCalc();
+
+            }
+        } catch (Throwable e) {
+            System.out.println(e);
+        } finally {
+            serverSocket.close();
+        }
+    }
+
+
+}

alfavre-alfavre/client/src/main/java/ch/heigvd/res/Protocol.java

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+package main.java.ch.heigvd.res;
+
+public class Protocol {
+
+    public static final int CALC_DEFAULT_PORT = 2020;
+
+    public static final String EOL = "\n";
+    public static final String ADD = "ADD";
+    public static final String SUB = "SUB";
+    public static final String MUL = "MUL";
+    public static final String DIV = "DIV";
+    public static final String OK = "OK";
+    public static final String NOK = "NOT OK";
+    public static final String START = "START";
+
+    public static final String OP[]={ADD,SUB,MUL,DIV};
+
+}

alfavre-alfavre/server/server.iml

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+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

alfavre-alfavre/server/src/main/java/ch/heigvd/res/App.java

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+package main.java.ch.heigvd.res;
+
+import java.io.IOException;
+
+public class App {
+
+    /**
+     *
+     * @param args the command line arguments
+     */
+    public static void main(String[] args) throws IOException {
+
+        Server server = new Server();
+        server.run();
+    }
+
+}

alfavre-alfavre/server/src/main/java/ch/heigvd/res/Protocol.java

@@ -0,0 +1,18 @@
+package main.java.ch.heigvd.res;
+
+public class Protocol {
+
+    public static final int CALC_DEFAULT_PORT = 2020;
+
+    public static final String EOL = "\n";
+    public static final String ADD = "ADD";
+    public static final String SUB = "SUB";
+    public static final String MUL = "MUL";
+    public static final String DIV = "DIV";
+    public static final String OK = "OK";
+    public static final String NOK = "NOT OK";
+    public static final String START = "START";
+
+    public static final String OP[]={ADD,SUB,MUL,DIV};
+
+}