Question

我有一个Java程序，并且在主类中有一个字符串类型的列表

public static List<String> Player_cards = new ArrayList<String>();

然后我尝试通过函数将项目添加到此列表中。

public static void func(){

    Player_cards.add("Hello");
}

，我尝试使用get在列表内打印值：

System.out.println(Player_cards.get(0));

当我尝试打印错误时：

Exception in thread "main" java.lang.Out0fMemoryError: Java heap space at 
    java.util.Arrays.copy0f(Arrays.java:3210) at java.util.Arrays.copy0f(Arrays.java:3181) at 
    java.util.ArrayList.grow(ArrayList.java:265) at 
    java.util.ArrayList.ensureExplicitCapacity(ArrayList.java:239) at 
    java.util.ArrayList.ensureCapacityInternal(ArrayList.java:231) at 
    java.util.ArrayList.add(ArrayList.java:462) 
    at Main.start(Main.java:116) 
    at Main.main(Main.java:142)

我还尝试打印完整列表：

System.out.println(Player_cards);

，但结果相同。这是我的整个代码：

import java.util.*;

public class Main
{
    public static String person_; //the murderer
    public static String place_;  //the place where crime committed
    public static String weapon_; //the weapon used in murder

    public static String[] Persons = {"Mr.Scarlet",
                                    "Prof.Plum",
                                    "Peacock",
                                    "Colonel Mustard",
                                    "Mr.Green",
                                    "Dr.Orchid"};

    public static String[] Places = {"Hall",
                                    "PianoRoom",
                                    "GreenHouse",
                                    "ReadingRoom",
                                    "Pool",
                                    "BedRoom",
                                    "DiningRoom",
                                    "Library",
                                    "Kichen"}; 

    public static String[] Weapons = {"knife",
                                    "shovel",
                                    "blade",
                                    "wrench",
                                    "rope",
                                    "bar"};


    public static String[] All = {"knife",
                                "shovel",
                                "blade",
                                "wrench",
                                "rope",
                                "bar",
                                "Hall",
                                "PianoRoom",
                                "GreenHouse",
                                "ReadingRoom",
                                "Pool",
                                "BedRoom",
                                "DiningRoom",
                                "Library",
                                "Kichen",
                                "Mr.Scarlet",
                                "Prof.Plum",
                                "Peacock",
                                "Colonel Mustard",
                                "Mr.Green",
                                "Dr.Orchid"};

    // public static String[] Player_cards = new String[3];
    // List Player_cards = new ArrayList();

    public static List<String> Player_cards = new ArrayList<String>();


    public static int move(int position){
        // this function input the position and return a random position based on 
        // rules of game.



        while(1==1){
            Random r = new Random();
            int dice_1 = 1+r.nextInt(6);
            int dice_2 = 1+r.nextInt(6);
            if((dice_1+dice_2)%2==0){
                int[] choices = {2,4,6,8};
                int rand = r.nextInt(4);
                if(choices[rand]!=position && choices[rand]!=position-1 && choices[rand]!= position+1){
                    System.out.printf("dice one:");
                    System.out.println(dice_1);
                    System.out.printf("dice two:");
                    System.out.println(dice_2);
                    return choices[rand];
                }
            }else{

                int[] choices = {1,3,5,7,9};
                int rand = r.nextInt(5);
                if(choices[rand]!=position && choices[rand]!=position-1 && choices[rand]!= position+1){
                    System.out.printf("dice one:");
                    System.out.println(dice_1);
                    System.out.printf("dice two:");
                    System.out.println(dice_2);
                    return choices[rand];
                }
            }
        }


    }

    public static void start(){
        //this function will start the game.
        //randomly choose 1 weapon, 1 person and 1 place as the solution of the game.

        Random r = new Random();
        int rand_person = r.nextInt(5);
        int rand_place = r.nextInt(8);
        int rand_weapon = r.nextInt(5);
        person_ = Persons[rand_person];
        place_ = Places[rand_place];
        weapon_ = Weapons[rand_weapon];

        while(true){

                    int rand_1 = r.nextInt(21);
                    if (All[rand_1] != person_ && All[rand_1] != place_ && All[rand_1] != weapon_){

                        Player_cards.add(All[rand_1]);

                    }

                    int rand_2 = r.nextInt(21);
                    if (All[rand_2] != person_ && All[rand_2] != place_ && All[rand_2] != weapon_){

                        Player_cards.add(All[rand_2]);

                    }

                    int rand_3 = r.nextInt(21);
                    if (All[rand_3] != person_ && All[rand_3] != place_ && All[rand_3] != weapon_){

                        Player_cards.add(All[rand_3]);

                    }

                }


    }

    public static void main(String[] args) {

            System.out.println(move(3));
            start();
           // System.out.println(Player_cards.toString());
            System.out.println(Player_cards);



    }
}

Answer 1

您有无限循环

while(1==1)

，这将占用您的全部内存。可能您忘了在循环中设置中断。

为什么我无法在Java中打印列表？

1 个答案: