java -/ArrayList 的文件写入问题

Question

编辑:程序现在仅写入第一个现有分数，如下所示:
文件大小(以行为单位)-
0- 正常写入。
1- 提示输入缩写，输出显示用户分数已添加到 myscores，但第一个分数是添加到文件中的分数。
2+- 与第二个类似，不提示输入缩写，第一个乐谱被写入文件两次。

import java.io.*;
import java.util.*;
import java.nio.file.*;
import java.text.*;

/* Notes:
 * High Scores Class:
 * Used to read/write high scores text file
 * */

/*
 * To do:
 * Fix reading/writing file
 * Fix sort as needed
 * FILTER OUT WHITESPACE WHEN READING
 */


public class HighScores 
{
    //user will input their 3 initials, must be 3
    public ArrayList<String> filearr;//hold file contents
    public BufferedReader hsds;//read initials in
    public ArrayList<Score> myscores;//hold all existing scores
    public ArrayList<String> vals;//hold filearr contents to be split and parsed
    public HighScores() //constructor
    { 
        myscores = new ArrayList<Score>();
        vals = new ArrayList<String>();
        hsds = new BufferedReader(new InputStreamReader(System.in));//for user input
        filearr = new ArrayList<String>();//holds values to be written to file
        System.out.println("File created.");
    }

    public void populate(Score uscore)
    //argument is score generated by user
    //this is called after game finishes
    //handles score(write or no?
    {
    Integer thescore = uscore.myscore;
    switch (filearr.size())
    {
    case 2://doesnt prompt for initials, writes first score twice each on a new line
    case 3:
    case 4:
    case 5:
    case 6:
    case 7:
    case 8:
    case 9:
    case 10:
        String strpos = "" + ((vals.get(0)).charAt(3));//remember strings are arrays!
        for (int i = 0; i < vals.size(); i++)
        {
            Score temp = new Score();
            String tempstr = vals.get(i);
            temp.initials = (tempstr.split(strpos)[0]);
            temp.myscore = Integer.parseInt((tempstr.split(strpos)[2]));
            myscores.add(temp);
        }
        int ssize = myscores.size();
        BubbleSort bsort = new BubbleSort();
        bsort.bubbleSort(myscores, ssize);//ssize is current size of scores
        System.out.println("Unsorted scores");
        for(int i = 0; i < myscores.size(); i++)
        {
            System.out.println("Score " + i + " : ");
            System.out.println("inits: " + (myscores.get(i).initials));
            System.out.println("myscore: " + ("" +(myscores.get(i).myscore)));
        }
    int max = myscores.size();
    int y = 0;
    Score sscore = new Score();
    sscore.myscore = thescore;

        if(sscore.myscore > (myscores.get(y)).myscore)//sorting algorithm
        {
            try
            {
            System.out.println("Please enter 3 initials to identify your high score.");
            String tinitials = "" + ((hsds.readLine()).toUpperCase());
            //initials are always formatted as upper case
                if (tinitials.length() > 3)
                {
                    String temp = tinitials.split(strpos)[0];
                    sscore.initials = temp;
                }
                else
                {
                    sscore.initials = tinitials;
                }
            hsds.close();
            }
            catch (Exception e)
            {
                e.printStackTrace();
            }
            if(sscore.myscore < (myscores.get(max - 1)).myscore)//smaller than largest
            {
                System.out.println("bigger, sm max");
                myscores.set(y, sscore);//in at 0
                y++;//now 1
                while ((myscores.get(y)).myscore < sscore.myscore)
                {
                    myscores.set(y-1, myscores.get(y));//shift this one down
                    myscores.set(y, sscore);//fill the hole
                    y++;//ends up at 5
                }
            }

            else if(sscore.myscore > (myscores.get(max-1)).myscore)//bigger than largest
            {
                System.out.println("bigger, gr max");
                Score temp = (myscores.get(max-1));
                myscores.set(max-1, sscore);//in at end
                y++;
                while(y < (max-1))
                {
                    myscores.set(y-1, myscores.get(y));//shift this one down
                    myscores.set(y, myscores.get(y+1));//fill the hole
                    y++;//ends up at 5
                }
                myscores.set(max-2, temp);
            }

            else if((sscore.myscore).equals((myscores.get(max-1)).myscore))//equal to largest
            {
                System.out.println("bigger, eq max");
                y++;//now 1
                while ((myscores.get(y)).myscore < sscore.myscore)
                {
                    myscores.set(y-1, myscores.get(y));
                    myscores.set(y, sscore);
                    y++;
                }
                myscores.set(y-1, sscore);
            }

            else
            {
                System.out.println("Oops.");
            }
        }
        else//smaller than first element
        {
            System.out.println("too small");
        }//end sort
        System.out.println("Sorted scores");
        for(int i = 0; i < myscores.size(); i++)
        {
            System.out.println("Score " + i + " : ");
            System.out.println("inits: " + (myscores.get(i).initials));
            System.out.println("myscore: " + ("" +(myscores.get(i).myscore)));
        }
    break;

    case 0://writes first score once
        Score newscore = new Score();
        newscore.myscore = thescore;
        try
        {
        System.out.println("Please enter 3 initials to identify your high score.");
        String tinitials = "" + ((hsds.readLine()).toUpperCase());
        //initials are always formatted as upper case
            if (tinitials.length() > 3)
            {
                strpos = "" + (tinitials.charAt(3));
                String temp = tinitials.split(strpos)[0];
                newscore.initials = temp;
            }
            else
            {
                newscore.initials = tinitials;
            }

        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        myscores.add(newscore);
    break;

    case 1://writes first score again on separate line
    newscore = new Score();
    newscore.myscore = thescore;
    strpos = "" + ((vals.get(0)).charAt(3));//remember strings are arrays!
    try
    {
    System.out.println("Please enter 3 initials to identify your high score.");
    String tinitials = "" + ((hsds.readLine()).toUpperCase());
    //initials are always formatted as upper case
        if (tinitials.length() > 3)
        {
            strpos = "" + (tinitials.charAt(3));
            String temp = tinitials.split(strpos)[0];
            newscore.initials = temp;
        }
        else
        {
            newscore.initials = tinitials;
        }

    }
    catch (Exception e)
    {
        e.printStackTrace();
    }
    for (int i = 0; i < vals.size(); i++)
    {
        Score temp = new Score();
        String tempstr = vals.get(i);
        temp.initials = (tempstr.split(strpos)[0]);
        temp.myscore = Integer.parseInt((tempstr.split(strpos)[2]));//works, idk why
        myscores.add(temp);
    }
    bsort = new BubbleSort();
    if (newscore.myscore > (myscores.get(0)).myscore)
    {
        myscores.add(newscore);
    }
    else
    {
        bsort.bubbleSort(myscores, myscores.size());
    }
    break;

    default:
    System.out.println("Invalid file supplied.");
    break;

    }

    }

    public void Save(PrintWriter writeme)//write everything to a file, filearr should be
    //the same size as it was upon object construction
    {
        for (int i = 0; i < myscores.size(); i++)
        {
            filearr.add(myscores.get(i).initials + "  " + ("" + (myscores.get(i).myscore))); //copy the finished list over
            writeme.println(filearr.get(i)); //write the list to the high scores file
            //writeme is myout in dsapp.java
        }
    }
}

未显示的类是 Score(分数对象模板)、Encrypter(数组生成和难度选择)、BubbleSort(冒泡排序算法)和 DSApp(应用程序文件，绘制 GUI 并执行文件操作)。评论应该解释一切；我可以根据需要提供更多代码。任何和所有的帮助将不胜感激。

Answer 1

• IndexOutOfBoundsExceptions 于:

  temp.myscore = Integer.parseInt((tempstr.split(strpos)[1]));
  

  表示 tempstr.split(strpos) 返回的数组少于 2 个项目(0 或 1)。在那里添加打印语句或逐步调试程序以找出原因应该相当容易。

• 无法正确写入文件

  这有点模糊(您是否遇到异常？文件已创建但无效？等等)