Java |.clear（）函数的问题

好的，这是我第二次在这里发帖，所以请原谅我提供了太多的信息和我的代码糟糕的状态。这是我正在玩的一个更大的程序的摘录，但我遇到了一个小问题。.clear函数在奇数时间出现错误，我无法查明原因。此功能用于根据输入显示相关的个性类型。输入es会显示es个性类型。其设计用于接收长度为0-4的输入

package MBTI_Experiment;

import java.util.Arrays;
import java.util.Scanner;
import java.util.ArrayList;
import java.util.List;

public class MBTI_Root {
    protected int counter = 0;
    protected List<String> selected_f = new ArrayList<>();
    protected List<String> selected_t = new ArrayList<>();
    protected String[] selected_t_1 = new String[16];
    protected String[] selected_t_2 = new String[8];
    protected String[] selected_t_3 = new String[4];
    protected String[] selected_t_4 = new String[2];
    protected double[] percentages = new double[] {0.0, 0.0};
    protected char[] functions = new char[] {'*', '*', '*', '*'};
    protected String[] types_array = new String[] {"intj", "intp", "entj", "entp", "infj", "infp", "enfj", "enfp",
                                                    "istj", "isfj", "estj", "esfj", "istp", "isfp", "estp", "esfp"};
    protected double[] m_percentages = new double[] {3.3, 4.8, 2.7, 4.0, 1.2, 4.1, 2.7, 6.4,
                                                        16.4, 8.1, 11.2, 7.5, 8.5, 7.6, 5.6, 6.9};
    protected double[] f_percentages = new double[] {0.9, 1.7, 0.9, 2.4, 1.6, 4.6, 3.3, 9.7,

                                                     6.9, 19.4, 6.3, 16.9, 2.3, 9.9, 3.0, 10.1};
 public MBTI_Root() {
        boolean valid = true;       // Resets boolean at the start of function
        while (valid) {
            reset_Percentages();
            System.out.println("\nBelow is a list of possible functions.");
            System.out.println("\n 1.  Run Gender Distribution \n 2.  Run Gender Distribution by Letter " +
                    "\n 3.  Run Gender Distribution by Function ");
            System.out.println(" 4.  Retrieve Type Information \n 0.  Terminate Program ");
            System.out.println("\nPlease Enter the Number of the Desired Function.");
            Scanner input_1 = new Scanner(System.in);
            int option = input_1.nextInt();

// Cut, but continues...

            else if (option == 2) {
                boolean cont = true;
                while (cont) {
                    reset_Selected_number(selected_t_1);
                    reset_Selected_number(selected_t_2);
                    reset_Selected_number(selected_t_3);
                    reset_Selected_number(selected_t_4);
                    reset_Selected_t();
                    reset_Percentages();
                    reset_Selected_f();
                    reset_Functions();
                    System.out.println("\nEnter the letter for desired functions. ");
                    Scanner input_3 = new Scanner(System.in);
                    String function = input_3.nextLine().toLowerCase();
                    MBTI_Function_2(function);
                    System.out.println("\nSelected function(s): " + selected_f.toString().substring(1,
                            selected_f.toString().length() - 1) + ".");
                    boolean not_empty = true;
                    for (String occupant : selected_t) {
                        if (occupant.isEmpty()) {
                            not_empty = false;
                            break;
                        }
                    }
                    if (not_empty) {
                        System.out.println("Types that include these functions: " + selected_t.toString().substring
                                (1, selected_t.toString().length() - 1).toUpperCase());
                    } else {
                        System.out.println("There are no types that include this combination of functions.");
                    }
                    cont = return_to_root("Enter more inputs?");
                }
            }

具体来说，我在使用.clear方法的reset_Selected_t时遇到问题。每当输入少于4个字符时，我就会收到一个错误。

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这是一个很长很圆的方法来解决这个问题，但是为什么我在这个清晰的函数上遇到了麻烦呢？它的近亲reset_Selected_f工作正常。

您的问题是Selected_t=Arrays.asListselected_t_1

Arrays.asList不会基于数组的内容创建新列表；它将现有数组包装在列表中。因此，对列表的更改将反映在数组中

在这种情况下，方法.clear会产生问题，因为它会从列表中删除所有元素。这对于内部数组是不可能的；它总是固定大小的。因此，它抛出一个异常

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如果您试图对Array.asList创建的列表使用add或remove，也会发生同样的情况。

将Array.asList替换为

selected_t = Arrays.stream(selected_t_1).collect(Collectors.toList());

或

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您得到的错误是什么，即堆栈跟踪？您写道：.clear函数出现错误，请回答您的问题并提供您得到的错误的详细信息。是的，我第二次发布的内容越少，在这里发布的内容越多，堆栈跟踪、错误消息的技术细节就越清晰、具体。

    protected void reset_Percentages() {
        percentages[0] = 0.0;
        percentages[1] = 0.0;
    }
    protected void reset_Selected_f() {
        selected_f.clear();
    }
    protected void reset_Functions() {
        Arrays.fill(functions, '*');
    }
    protected void reset_Counter() {
        counter = 0;
    }
    protected void reset_Selected_t() {
        selected_t.clear();
    }
    protected void reset_Selected_number(String[] function) {
        Arrays.fill(function, "");
    }

selected_t = Arrays.stream(selected_t_1).collect(Collectors.toList());

selected_t = new ArrayList<>(Arrays.asList(selected_t_1));