make CommandFactory singleton

src/command/InfoCommand.java

-package command;
-
-import model.Command;
-import util.Response;
-
-import java.io.IOException;
-import java.io.OutputStream;
-import java.util.List;
-import java.util.Map;
-import java.util.stream.Collectors;
-
-public class InfoCommand implements CommandHandler {
-    private final Configuration configuration = Configuration.getInstance();
-
-    @Override
-    public void execute(List<String> args, OutputStream os) {
-        System.out.println(configuration.getInfo());
-        String command = args.getFirst();
-        if (command.equalsIgnoreCase(Command.REPLICATION.getValue())) {
-            Map<String, String> info = configuration.getInfo();
-            String response = info.entrySet()
-                    .stream()
-                    .map(data -> data.getKey() + ":" + data.getValue())
-                    .collect(Collectors.joining());
-            try {
-                os.write(Response.getResponse(response));
-                os.flush();
-            } catch (IOException e) {
-                throw new RuntimeException(e);
-            }
-        }
-
-
-    }
-}
\ No newline at end of file

src/factory/CommandFactory.java

@@ -4,19 +4,26 @@ import command.*;
 import model.Command;
 
 public class CommandFactory implements Factory {
-    private final Command command;
 
-    public CommandFactory(Command command) {
-        this.command = command;
+    private static final class FactoryHolder {
+        private static final CommandFactory factory = new CommandFactory();
     }
 
-    public CommandHandler getInstance() {
+    public CommandFactory() {
+
+    }
+
+    public static CommandFactory getInstance() {
+        return FactoryHolder.factory;
+    }
+
+    @Override
+    public CommandHandler getCommand(Command command) {
         return switch (command) {
             case PING -> new PingCommand();
             case ECHO -> new EchoCommand();
             case SET -> new SetCommand();
             case GET -> new GetCommand();
-            case INFO -> new InfoCommand();
 //            case REPLCONF -> new ReplConfCommand(replicaReceiver);
 //            case PSYNC -> new FullResyncCommandProcessor(replicaSender);
 //            case WAIT -> new WaitCommandProcessor(replicaSender, replicaReceiver);

src/factory/Factory.java

@@ -2,7 +2,8 @@ package factory;
 
 
 import command.CommandHandler;
+import model.Command;
 
 public interface Factory {
-    CommandHandler getInstance();
+    CommandHandler getCommand(Command command);
 }

src/handlers/ClientCommandHandler.java

@@ -4,7 +4,6 @@ import command.CommandHandler;
 import command.CommandInvoker;
 import factory.CommandFactory;
 import model.Command;
-import parser.CommandParser;
 import util.CommandUtil;
 
 import java.io.IOException;
@@ -14,24 +13,23 @@ import java.util.List;
 public class ClientCommandHandler {
     private final List<String> commands;
     private final OutputStream os;
+    private final CommandFactory factory = CommandFactory.getInstance();
 
     public ClientCommandHandler(List<String> commands, OutputStream outputStream) {
         this.commands = commands;
         this.os = outputStream;
-        CommandParser commandParser = new CommandParser();
     }
 
 
-    public boolean execute() {
+    public void execute() {
         Command command = CommandUtil.getCommand(commands.getFirst());
         commands.removeFirst();
-        CommandHandler commandProcessor = new CommandFactory(command).getInstance();
+        CommandHandler commandProcessor = factory.getCommand(command);
         try {
             CommandInvoker.invoke(commandProcessor, commands, os);
         } catch (IOException e) {
             throw new RuntimeException(e);
         }
-        return false;
     }