assembled a working update workflow

jams-common/src/main/java/net/jami/jams/common/updater/FullSystemStatusResponse.java

+package net.jami.jams.common.updater;
+
+import lombok.Getter;
+import lombok.Setter;
+
+import java.util.HashMap;
+
+@Getter
+@Setter
+public class FullSystemStatusResponse {
+
+    private HashMap<String,FileDescription> localVersions;
+    private HashMap<String, FileDescription> remoteVersions;
+    private Boolean updateAvailable;
+
+}

jams-launcher/pom.xml

@@ -57,6 +57,8 @@
                                         implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                     <manifestEntries>
                                         <Main-Class>launcher.AppStarter</Main-Class>
+                                        <Implementation-Title>${project.artifactId}</Implementation-Title>
+                                        <Implementation-Version>${project.version}</Implementation-Version>
                                         <Class-Path>.</Class-Path>
                                     </manifestEntries>
                                 </transformer>

jams-server/src/main/java/net/jami/jams/server/servlets/api/update/SubscriptionServlet.java → jams-server/src/main/java/net/jami/jams/server/servlets/api/admin/update/SubscriptionServlet.java

-package net.jami.jams.server.servlets.api.update;
+package net.jami.jams.server.servlets.api.admin.update;
 
 import com.jsoniter.output.JsonStream;
 import jakarta.servlet.ServletException;

jams-server/src/main/java/net/jami/jams/server/servlets/api/update/UpdateServlet.java → jams-server/src/main/java/net/jami/jams/server/servlets/api/admin/update/UpdateServlet.java

-package net.jami.jams.server.servlets.api.update;
+package net.jami.jams.server.servlets.api.admin.update;
 
+import com.jsoniter.output.JsonStream;
 import jakarta.servlet.ServletException;
 import jakarta.servlet.annotation.WebServlet;
 import jakarta.servlet.http.HttpServlet;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
+import net.jami.jams.common.updater.FullSystemStatusResponse;
 
 import java.io.IOException;
 
+import static net.jami.jams.server.Server.appUpdater;
+
 @WebServlet("/api/update")
 public class UpdateServlet extends HttpServlet {
 
     //Return the current version number and the available version number.
     @Override
     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
-        super.doGet(req, resp);
+        FullSystemStatusResponse response = new FullSystemStatusResponse();
+        response.setLocalVersions(appUpdater.getLocalVersions());
+        response.setRemoteVersions(appUpdater.getRemoteVersions());
+        response.setUpdateAvailable(appUpdater.getUpdateAvailable());
+        resp.getOutputStream().write(JsonStream.serialize(response).getBytes());
     }
 
     //This is the do-update button.
     @Override
     protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
-        super.doPost(req, resp);
+        if(appUpdater.getUpdateAvailable()){
+            appUpdater.doUpdate();
+        }
     }
 }

updater/src/main/java/net/jami/jams/updater/UpdateCheckTask.java

@@ -69,7 +69,8 @@ public class UpdateCheckTask extends TimerTask {
             );
             //Compare and set to to true up-stream
             localData.forEach((k,v) -> {
-                if(remoteData.get(k).compareTo(v) > 0){
+                if(remoteData.containsKey(k) && remoteData.get(k).compareTo(v) > 0){
+                    log.info("Detected a new version on SFL servers!");
                     JAMSUpdater.updateAvailable.set(true);
                 }
             });