一个ArrayList，它应该具有来自已创建类的对象，但打印为null

Question

我的第一个类创建ArrayList并用技能对象填充它

import java.util.ArrayList;
public class Skill {
String skillName;
int skillValue;
public static ArrayList<Skill> skillList = new ArrayList<Skill>();
public Skill(String newSkillName, int newSkillValue){
setSkillName(newSkillName);
setSkillValue(newSkillValue);
}
public static void initializeSkillList(){
//Creating the Skill obj's
Skill str = new Skill("Str", 1);
Skill dex = new Skill("Dex", 1);
Skill intl = new Skill("Int", 1);
Skill con = new Skill("Con", 3);
//Adding them to the Skill ArrayList
skillList.add(str);
skillList.add(dex);
skillList.add(intl);
skillList.add(con);
//Debug statement to check if the values are correct
System.out.println(skillList.get(1).skillValue);
}
}

我正试图从Main.java类的ArrayList访问对象skillValue和skillName。我有二传手和传接球手。这是主类

import java.util.Scanner;
public class Main {
static Character playerCharacter;
static boolean charCreationComplete = false;
static boolean endGame = false;
static Scanner scnr = new Scanner(System.in);
public static void main(String[] args){
System.out.println("nnWelcome to Garterra!nn");
Archetype.initializeArchetypeList();
Skill.initializeSkillList();
if (!charCreationComplete){
charCreation(scnr);
charCreationComplete = true;
}

charCreation(scnr);然后通过getter和setter 访问skillList

charCreation((方法：

private static void charCreation(Scanner scnr){
System.out.println("nEnter player name:nn");
String newName = scnr.nextLine();
System.out.println("You Entered " + newName + " for your name!n");
System.out.println("Next, Choose your Archetype: 0 = Rangern");
int archetypeIndex = scnr.nextInt();
Character.currArchetype = Archetype.archetypeList.get(archetypeIndex);
Character.archetypeName = Archetype.archetypeList.get(archetypeIndex).getArchetypeName();
System.out.println("You have chosen " + Character.archetypeName + ".nThis gives you " + Character.currArchetype.totalSpendableSkillPoints + " total spendable skill points!n");
System.out.println("Now, spend those skill points.n");
if (Character.currArchetype.getArchetypeName().contains("Ranger")){
Ranger.dexModifierCalc(1);
Ranger.conModifierCalc(1);
}
while (Character.currArchetype.totalSpendableSkillPoints > 0){
System.out.println("How many points would you like to put into Strength?nThis impacts your melee weapon damage and carry weight.n");
int strAddPoints = scnr.nextInt();
Skill.skillList.get(0).setSkillValue(Skill.skillList.get(0).getSkillValue() + strAddPoints);
Character.currArchetype.setTotalSpendableSkillPoints(Character.currArchetype.totalSpendableSkillPoints - strAddPoints);
strAddPoints = 0;
System.out.println("You now have " + Skill.skillList.get(0).getSkillValue() + "n");
if (Character.currArchetype.totalSpendableSkillPoints == 0){
break;
}
if (Character.currArchetype.totalSpendableSkillPoints > 0){
System.out.println("How many points would you like to put into Dexterity?nThis impacts your ranged weapon damage.n");
int dexAddPoints = scnr.nextInt();
Skill.skillList.get(1).setSkillValue(Skill.skillList.get(1).getSkillValue() + dexAddPoints);
Character.currArchetype.setTotalSpendableSkillPoints(Character.currArchetype.totalSpendableSkillPoints - dexAddPoints);
dexAddPoints = 0;
System.out.println("You now have " + Skill.skillList.get(1).getSkillValue() + "n");
}
if (Character.currArchetype.totalSpendableSkillPoints == 0){
break;
}
if (Character.currArchetype.totalSpendableSkillPoints > 0){
System.out.println("How many points would you like to put into Intelligence?nThis impacts your magic damage.n");
int intAddPoints = scnr.nextInt();
Skill.skillList.get(2).setSkillValue(Skill.skillList.get(2).getSkillValue() + intAddPoints);
Character.currArchetype.setTotalSpendableSkillPoints(Character.currArchetype.totalSpendableSkillPoints - intAddPoints);
intAddPoints = 0;
System.out.println("You now have " + Skill.skillList.get(2).getSkillValue() + "n");
}
if (Character.currArchetype.totalSpendableSkillPoints == 0){
break;
}
if (Character.currArchetype.totalSpendableSkillPoints > 0){
System.out.println("How many points would you like to put into Strength?nThis impacts your melee weapon damage and carry weight.n");
int conAddPoints = scnr.nextInt();
Skill.skillList.get(3).setSkillValue(Skill.skillList.get(3).getSkillValue() + conAddPoints);
Character.currArchetype.setTotalSpendableSkillPoints(Character.currArchetype.totalSpendableSkillPoints - conAddPoints);
conAddPoints = 0;
System.out.println("You now have " + Skill.skillList.get(3).getSkillValue() + "n");
}
}
int newHealthPoints = Character.healthPointsCalc();
System.out.println("You have " + newHealthPoints + " health points!nn");
int newTotalCarryWeight = Character.carryWeightCalc(Character.currArchetype.getLevel());
System.out.println("Your total carry weight is " + newTotalCarryWeight + ".n");
int newExperince = 0;
playerCharacter = new Character(newName, newHealthPoints, newExperince, 1, Archetype.archetypeList.get(archetypeIndex), newTotalCarryWeight);
}

Answer 1

如果您为"skillList"；那么你可以说

Skill.getSkillList();

然后用这个列表做任何你想做的事。为了让你的代码更好一点，更改这个

public static ArrayList<Skill> skillList = new ArrayList<>();

到这个

public static List<Skill> skillList = new ArrayList<>();