update,

_resources/it114105/itp4507/Assignment/20-21/src/CommandHandler.java

@@ -0,0 +1,47 @@
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+/**
+ *
+ * @author jerrykwok
+ */
+public class CommandHandler {
+
+    private LinkedHashMap<String, CommandFactory> mapCmds;
+
+    public CommandHandler() {
+        this.mapCmds = new LinkedHashMap<String, CommandFactory>();
+    }
+
+    public void regCommand(String key, CommandFactory cmdFactory) {
+        mapCmds.put(key, cmdFactory);
+    }
+
+    public void printCommandList() {
+        System.out.print("Please enter command: [");
+        System.out.print(String.join(" | ", mapCmds.keySet()));
+        System.out.println("]");
+        for (Map.Entry<String, CommandFactory> mapCmd : mapCmds.entrySet()) {
+            System.out.print(mapCmd.getKey() + " = " + mapCmd.getValue().getCommnadDesc());
+        }
+        System.out.println();
+    }
+    
+    public boolean run(String cmd) {
+        CommandFactory commandFactory = mapCmds.get(cmd);
+        if (commandFactory != null) {
+            Command command = commandFactory.createCommand();
+            command.execute();
+            
+            return true;
+        }
+
+        return false;
+    }
+}