modernmobile
New Member
I am doing a piece of coursework in Java using BlueJ. We need to add new features to the text based game, Zuul. I have decided to start working on an inventory and item system. I am having trouble working out the best way to do this so I just winged it. Here is my code. Sorry I haven't gotten round to commenting everything yet. The game compiles but I get an exception in the console when I run the game.Error:\[code\]java.lang.NullPointerException at Game.createPlayer(Game.java:15) at Game.<init>(Game.java:7) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:525) at bluej.runtime.ExecServer$3.run(ExecServer.java:740)\[/code\]Game Class (This is equivalent of the Main class in Java, this is where the game is run from):\[code\]import java.util.*;public class Game{ public Game() { createPlayer(); createItems(); } private Entity localPlayer; public void createPlayer(){ Player localPlayer = new Player("Player Name", 0, 0, 0, 0, 0); localPlayer.equipArmour("Helm", armourDB.get("Helm")); // This is where I think I have gone wrong } // Create global hashmap variables private HashMap<String, Weapon> weaponsDB; private HashMap<String, Armour> armourDB; private HashMap<String, Supplement> supplementDB; public void createItems(){ // Create weapons weaponsDB = new HashMap<String, Weapon>(); Weapon weaponFists = new Weapon("Fists", "Weapon", 0, 0, 0, 0, 0, "Melee"); Weapon weaponSword = new Weapon("Sword", "Weapon", 0, 0, 0, 0, 0, "Melee"); Weapon weaponBow = new Weapon("Bow", "Weapon", 0, 0, 0, 0, 0, "Ranged"); Weapon weaponDagger = new Weapon("Dagger", "Weapon", 0, 0, 0, 0, 0, "Melee"); weaponsDB.put("Fists", weaponFists); weaponsDB.put("Sword", weaponSword); weaponsDB.put("Bow", weaponBow); weaponsDB.put("Dagger", weaponDagger); // Create armour armourDB = new HashMap<String, Armour>(); Armour armourBreastplate = new Armour("Breatplate", "Chest", 0, 0, 0, 0, 0); Armour armourHelm = new Armour("Helm", "Head", 0, 0, 0, 0, 0); armourDB.put("Breastplate", armourBreastplate); armourDB.put("Helm", armourHelm); // Create supplements supplementDB = new HashMap<String, Supplement>(); Supplement supplementHealthPotion = new Supplement("Health Potion", 0, 0); Supplement supplementPowerPotion = new Supplement("Power Potion", 0, 0); supplementDB.put("Health Potion", supplementHealthPotion); supplementDB.put("Power Potion", supplementPowerPotion); }}\[/code\]Entity Class (Construction for the player class and enemy class):\[code\]import java.util.*;public class Entity{ private boolean entityStatus; private String entityName; private int entityHealth; private int entityPower; private int entityHealthRegen; private int entityPowerRegen; private int entityAttackPower; private HashMap<String, Armour> entityEquipment; private ArrayList<Item> entityInventory; public Entity( String paramEntityName, int paramEntityHealth, int paramEntityPower, int paramEntityHealthRegen, int paramEntityPowerRegen, int paramEntityAttackPower) { entityStatus = true; entityName = paramEntityName; entityHealth = paramEntityHealth; entityPower = paramEntityPower; entityHealthRegen = paramEntityHealthRegen; entityPowerRegen = paramEntityPowerRegen; entityAttackPower = paramEntityAttackPower; entityEquipment = new HashMap<String, Armour>(); // Set all possible equipment slots to null on initial run entityEquipment.put("Head", null); entityEquipment.put("Shoulders", null); entityEquipment.put("Chest", null); entityEquipment.put("Hands", null); entityEquipment.put("Legs", null); entityEquipment.put("Feet", null); entityEquipment.put("Weapon", null); entityInventory = new ArrayList<Item>(); } public boolean getEntityStatus(){ return entityStatus; } public String getEntityName(){ return entityName; } public int getEntityHealth(){ return entityHealth; } public int getEntityPower(){ return entityPower; } public int getEntityHealthRegen(){ return entityHealthRegen; } public int getEntityPowerRegen(){ return entityPowerRegen; } public int getEntityAttackPower(){ return entityAttackPower; } // Equips the player with an item into the equipment slot public void equipArmour(String paramEquipmentSlot, Armour paramArmourName){ entityEquipment.put(paramEquipmentSlot, paramArmourName); } public void printInventory(){ System.out.println("Something"); }}\[/code\]I think the main problem is that I cannot wrap my head around the use of hashtags, I need to see a live example to see how it works. Can anyone help? If you need anything else from me, let me know.