Java IndexOutOfBoundsException添加长数字时出错

Java IndexOutOfBoundsException添加长数字时出错,java,linked-list,indexoutofboundsexception,Java,Linked List,Indexoutofboundsexception,我正在尝试编写一个java应用程序,它使用LinkedList将5个长数字相加。在跑步结束时,我得到以下信息: 主线程java.lang.IndexOutOfBoundsException中的异常:索引: 0,大小:0 在java.util.LinkedList.checkElementIndexLinkedList.java:555在java.util.LinkedList.removeLinkedList.java:525在 Assignment1.LongNumbers.removeLon

我正在尝试编写一个java应用程序,它使用LinkedList将5个长数字相加。在跑步结束时,我得到以下信息:

主线程java.lang.IndexOutOfBoundsException中的异常:索引: 0,大小:0 在java.util.LinkedList.checkElementIndexLinkedList.java:555在java.util.LinkedList.removeLinkedList.java:525在 Assignment1.LongNumbers.removeLongNumbers.java:33 at Assignment1.LongNumbers.mainLongNumbers.java:92

代码如下:

import java.util.*;
/**
*
* @author .....
*/

public class LongNumbers 
{ 
private List<Integer> [] theLists; 
public LongNumbers() { 
    this.theLists = new LinkedList[6]; 
    for (int i=0; i<6; i++) 
    this.theLists[i]= new LinkedList<>(); 
} 

public void add(int location, int digit) { 
    //add digit at head of LinkedList given by location 
    theLists[location].add(digit);
} 

public int remove(int location) { 
    //remove a digit from LinkedList given by location
    return theLists[location].remove(location);  //LongNumbers.java:33
} 

public boolean isEmpty(int location) { 
    //check for an empty LinkedList given by location
    return theLists[location].isEmpty();
} 

public static void main(String[] args) { 
    Scanner stdIn = new Scanner(System.in);

     //Local Variables
    int digit;
    int carry = 0;
    int numberAt = 0;
    int largestNumLength = 0;
    char[] digits;
    String number;
    boolean userWantstoQuit = false;
    LongNumbers Lists = new LongNumbers();

    System.out.println("The program will enter up to 5 numbers and add them up.");
    System.out.println();

    while(!userWantstoQuit && numberAt != 5){
        System.out.print("Enter a number, enter -1 to quit entry phase: ");
        number = stdIn.nextLine();

        if((number.compareTo("-1")) == 0)
            userWantstoQuit = true;
        else{
            digits = new char[number.length()];
            for(int i=0;i<number.length();i++)
                digits[i] = number.charAt(i);
            for(int i=0;i<number.length();i++){
                int tempValue = digits[i] - 48;
                try{
                    Lists.add(numberAt, tempValue);
                }
                    catch(NumberFormatException nfe){
                        System.out.println("Invalid Input. Please try again.");
                        break;
                    }
                if(i == (number.length() - 1))
                    numberAt++;
                if(number.length() > largestNumLength)
                    largestNumLength = number.length();
            }
        }
    }

    for(int j=0;j<largestNumLength;j++){
        int tempDigit = 0;
        int index = 0;

        while(index < numberAt){
            if(Lists.theLists[index].get(0) != null){
                tempDigit += Lists.theLists[index].get(0);
                Lists.remove(0);  //LongNumbers.java:99                        
            }
        index++;
        }

        digit = carry + tempDigit;

        if(j < numberAt){
            carry = digit/10;
            digit = digit%10;
        }
    Lists.add(5, digit);
    }

    System.out.print("The sum of the numbers is: ");

    for(int i=0;i<Lists.theLists[5].size();i++){
        System.out.print(Lists.theLists[5].get(i));
    }

    System.out.println();
    System.out.println();
    System.out.println();

}//end main 
}//end class

首先,我不认为你可以有一个列表对象数组

您还应该确保列表已初始化,并且在给定位置有一个项目

因此,您的方法可能如下所示:

public int remove(int location)
{ 
     if(theLists != null)
          if(theLists.size() > location)
               return theLists.remove(location);
     return 0;
}
public int remove(int location, int index) { 
    //remove a digit from LinkedList given by location
    return theLists[index].remove(location);  //LongNumbers.java:33
} 
如果需要列表的两个维度,可以尝试使用列表

将所有E都视为整数。

请查看此处的代码:

while(index < numberAt){
            if(Lists.theLists[index].get(0) != null){
                tempDigit += Lists.theLists[index].get(0);
                Lists.remove(0);  //LongNumbers.java:99                        
            }
        index++;
        }
在我描述的场景中,位置是0。但您的第0个列表已为空

编辑:重写删除方法,如下所示:

public int remove(int location)
{ 
     if(theLists != null)
          if(theLists.size() > location)
               return theLists.remove(location);
     return 0;
}
public int remove(int location, int index) { 
    //remove a digit from LinkedList given by location
    return theLists[index].remove(location);  //LongNumbers.java:33
} 
无论何时调用此方法,都要传递要使用的列表的索引。例如:

while(index < numberAt){
            if(Lists.theLists[index].get(0) != null){
                tempDigit += Lists.theLists[index].get(0);
                Lists.remove(0, index);  //LongNumbers.java:99                        
            }
        index++;
        }

最后:在将来,请结构化您的代码,在这种非结构化的状态下阅读它是一件非常痛苦的事情,阅读如何编写代码。

如果您能在代码中指出行的长度,那就太好了。java:33抱歉了。编辑已完成。堆栈跟踪非常清楚地告诉您,在remove方法中,您请求的是一个大小为零的列表的索引0处的元素,即一个空列表。看看你是如何初始化列表的。