Add: Implement CommandHandlerExecutor for evaluation of pre-execution checks in CommandRouter

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/ServerApp.java

@@ -15,6 +15,7 @@ import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.ping.PingRequest;
 import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.UserCleanupJob;
 import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.UserRegistry;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.NetworkManager;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandHandlerExecutor;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandRouter;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.command.parsing.CommandParserDispatcher;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.events.DisconnectEvent;
@@ -48,7 +49,8 @@ public class ServerApp {
         CommandParserDispatcher dispatcher = new CommandParserDispatcher();
         SessionManager sessionManager = new SessionManager(eventBus, dispatcher);
         ResponseDispatcher responseDispatcher = new ResponseDispatcher(sessionManager);
-        CommandRouter router = new CommandRouter();
+        CommandHandlerExecutor handlerExecutor = new CommandHandlerExecutor(responseDispatcher);
+        CommandRouter router = new CommandRouter(handlerExecutor);
 
         eventBus.subscribe(DisconnectEvent.class, event -> sessionManager.onDisconnect(event));
 

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/network/command/execution/CommandHandlerExecutor.java

@@ -0,0 +1,27 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.checks.HandlerCheck;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.Request;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.Response;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.dispatcher.ResponseDispatcher;
+import java.util.Optional;
+
+public class CommandHandlerExecutor {
+    private final ResponseDispatcher responseDispatcher;
+
+    public CommandHandlerExecutor(ResponseDispatcher responseDispatcher) {
+        this.responseDispatcher = responseDispatcher;
+    }
+
+    public void execute(CommandHandler<Request> handler, Request request) {
+        for (HandlerCheck check : handler.getChecks()) {
+            Optional<Response> result = check.check(request);
+            if (result.isPresent()) {
+                responseDispatcher.dispatch(result.get());
+                return;
+            }
+        }
+
+        handler.execute(request);
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/network/command/execution/CommandRouter.java

@@ -6,6 +6,11 @@ import java.util.Map;
 
 public class CommandRouter {
     private final Map<Class<? extends Request>, CommandHandler<?>> handlers = new HashMap<>();
+    private final CommandHandlerExecutor handlerExecutor;
+
+    public CommandRouter(CommandHandlerExecutor commandHandlerExecutor) {
+        this.handlerExecutor = commandHandlerExecutor;
+    }
 
     public <T extends Request> void register(Class<T> request, CommandHandler<T> handler) {
         handlers.put(request, handler);
@@ -23,6 +28,7 @@ public class CommandRouter {
             throw new UnknownRequestException(
                     "Unable to execute request " + requestName + ". Type unknown", requestName);
         }
-        handler.execute(request);
+
+        handlerExecutor.execute(handler, request);
     }
 }