updating server side implemented

server/src/main/java/com/kritsit/casetracker/server/domain/services/ClientConnectionThread.java

@@ -156,6 +156,35 @@ public void run() {
                         writeResponse(dto);
                         break;
                     }
+                    case "checkForUpdate" : {
+                        try {
+                            String currentVersion = (String) request.getArguments().get(0);
+                            logger.debug("Checking for update to client version {}", currentVersion);
+                            IUpdateService updater = new Updater();
+                            boolean updateRequired = updater.isUpdateRequired(currentVersion);
+                            Response dto = new Response(200, updateRequired);
+                            writeResponse(dto);
+                        } catch (IOException ex) {
+                            logger.error("Error occurred checking for update to client", ex);
+                            Response dto = new Response(404, "Client archive not found");
+                            writeResponse(dto);
+                        }
+                        break;
+                    }
+                    case "getUpdate" : {
+                        try {
+                            IUpdateService updater = new Updater();
+                            byte[] update = updater.getUpdate();
+                            Response dto = new Response(200, update);
+                            writeResponse(dto);
+                        } catch (IOException ex) {
+                            logger.error("Error occurred getting update to client", ex);
+                            Response dto = new Response(500, 
+                                    "Client archive cannot be serialized");
+                            writeResponse(dto);
+                        }
+                        break;
+                    }
                     case "close" : {
                         close();
                         logger.info("{} has disconnected", connectedClient);

server/src/main/java/com/kritsit/casetracker/server/domain/services/IUpdateService.java

@@ -0,0 +1,8 @@
+package com.kritsit.casetracker.server.domain.services;
+
+import java.io.IOException;
+
+public interface IUpdateService {
+    boolean isUpdateRequired(String currentVersion) throws IOException;
+    byte[] getUpdate() throws IOException;
+}

server/src/main/java/com/kritsit/casetracker/server/domain/services/Updater.java

@@ -0,0 +1,65 @@
+package com.kritsit.casetracker.server.domain.services;
+
+import com.kritsit.casetracker.shared.domain.FileSerializer;
+
+import org.slf4j.LoggerFactory;
+import org.slf4j.Logger;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.InputStreamReader;
+import java.io.IOException;
+
+public class Updater implements IUpdateService {
+    private final Logger logger = LoggerFactory.getLogger(Updater.class);
+    private File root;
+
+    public Updater() {
+        root = new File("");
+    }
+
+    public boolean isUpdateRequired(String currentVersion) throws IOException {
+        logger.debug("Checking for update for client version {}", currentVersion);
+        File client = findClientArchive();
+        String requiredVersion = getLatestVersion(client);
+        return !currentVersion.equals(requiredVersion);
+    }
+
+    public byte[] getUpdate() throws IOException {
+        File client = findClientArchive();
+        FileSerializer serializer = new FileSerializer();
+        return serializer.serialize(client);
+    }
+
+    private File findClientArchive() throws FileNotFoundException {
+        logger.debug("Finding client archive...");
+        File[] files = root.listFiles();
+        for (File file : files) {
+            String fileName = file.getName();
+            if (fileName.contains("client") && fileName.endsWith(".jar")) {
+                return file;
+            }
+        }
+        throw new FileNotFoundException("Unable to find client archive in " + 
+                root.getAbsolutePath());
+    }
+
+    private String getLatestVersion(File client) throws IOException {
+        logger.debug("Running client to get version...");
+        Process clientProcess = new ProcessBuilder("java", "-jar", 
+                client.getAbsolutePath(), "--version").start();
+        InputStreamReader inReader = 
+            new InputStreamReader(clientProcess.getInputStream());
+        BufferedReader in = new BufferedReader(inReader);
+        String line;
+        while ((line = in.readLine()) != null) {
+            logger.debug("Output: {}", line);
+            if (line.contains("Version: ")) {
+                return line.replace("Version: ", "");
+            }
+        }
+        throw new IOException("Unable to find version of client archive " + 
+                client.getAbsolutePath());
+    }
+}