數組索引超出範圍例外問題

我目前在我的數組中遇到了一個越界問題，而且我真的不確定我到底在哪裏出錯了。我真的很想再看看這件事情，因爲我會失去理智。數組索引超出範圍例外問題

我誠摯地感謝任何幫助。不是：謝謝。

package com.jpmorgan.spring.csv; 

import java.io.BufferedReader; 
import java.io.FileNotFoundException; 
import java.io.FileReader; 
import java.io.IOException; 

public class CSVRead { 
    static void read() throws IOException { 
     String csvFileToRead = "profit.csv"; 
     BufferedReader br = null; 
     String line = ""; 
     String splitBy = ","; 

     try { 
      br = new BufferedReader(new FileReader(csvFileToRead)); 

      while ((line = br.readLine()) != null) { 
       String[] array = line.split(splitBy); 
       System.out.println("Equity & Bonds: [Instrument Type= " + array[0] + " , Name=" + array[1] + " , Quantity=" + array[2] 
           + " , Buy=" + array[3] + " , Sell=" + array[4] + /*" , Coupon=" + array[5] +*/ "]"); 
      } 

     } 
     catch (FileNotFoundException e) { 
      e.printStackTrace(); 
     } 
     catch (IOException e) { 
      e.printStackTrace(); 
     } 
     finally { 
      if (br != null) { 
       try { 
        br.close(); 
       } catch (IOException e) { 
        e.printStackTrace(); 
       } 
      } 
     } 
     System.out.println("Done reading CSV file"); 
    } 
}

這是完整的CSV文件。我試過使用調試，但它沒有太大的幫助。

instrument_type,name,quantity,buy_price,sell_price,coupon 
Equity,AAA,123,1.01,1.10 
Equity,BBBB,3,1.05,1.01 
Bond,CCC,3,,,0.13 
Equity,AAA,12,1.11,1.13 
Bond,DD,3,,,1.24

主要參考。

/** 
* Main class is menu driven, receives CSV input. 
* This program reads, calculates and writes CSV files. 
* @author David McNeill 
* @version 1.0 - 17/03/1015 
*/ 

package com.jpmorgan.spring.csv; 
import java.util.Scanner; 
public class CSVMain{ 

    public static void main(String[] arg) throws Exception { 
     @SuppressWarnings("resource") 
     Scanner in = new Scanner(System.in); 
     int userChoice; 
     boolean quit = false; 
     do { 
     System.out.println("Please choose an option using 1 - 4");      //print text to screen 
     System.out.println("------------------------------------");      //print text to screen 
     System.out.println("1: Read 'input' CSV file");         //print text to screen 
     System.out.println("2: Calculate 'input' CSV file");       //print text to screen 
     System.out.println("3: Write calculation result to CSV file");     //print text to screen 
     System.out.println("4: Exit program");           //print text to screen 
      userChoice = in.nextInt();             //'in' equals integer 
      if (userChoice == 4)              //when '3' is input then... 
        quit = true;               //the program will now quit 
      else if (userChoice == 1)             //when '1' is input then... 
        CSVRead.read(); 
      else if (userChoice == 2); 
       //####################calculations go here#########################    
       //####################calculations go here######################### 
       //####################calculations go here######################### 
      else if (userChoice == 3) 
        CSVWrite.write(); 
     } while (!quit); 
    } 
}

來源

2015-03-18 David McNeill

u能更新與CSV的前幾排的問題做CSVRead.main();？ – 2015-03-18 21:15:05

你的代碼假設'line.split（splitBy）'將返回一個至少有5個條目的數組（6個帶有註釋掉的位）。顯然它不是。所以你必須看看這條線並找出原因。調試器是最好的方法，單步執行代碼。 – 2015-03-18 21:15:18

是的，從'split'方法調試它。此外，如果文件有一些不同的標題，則會導致問題。這就是爲什麼我問前2-3排。 – 2015-03-18 21:16:46

分割線後，你應該確保你得到正確的列數。

我無法告訴你如何解決潛在的不良數據，但我可以幫助您識別它。只是這種替換內環：

int lineNum = 0; 
while ((line = br.readLine()) != null) { 
    String[] array = line.split(splitBy); 
    if (array.length < 5) 
     throw new Exception("There's a problem with " + csvFileToRead + " on line " + lineNum + ":\n" + line);   
    System.out.println("Equity & Bonds: [Instrument Type= " + array[0] + " , Name=" + array[1] + " , Quantity=" + array[2] 
          + " , Buy=" + array[3] + " , Sell=" + array[4] + /*" , Coupon=" + array[5] +*/ "]"); 
    lineNum++; 
}

來源

2015-03-18 21:15:35 axblount

我該怎麼做到這一點？ – 2015-03-18 21:42:57

@David我添加了一個示例來幫助您調試問題。 – axblount 2015-03-18 21:55:48

謝謝。您的異常現在似乎顯示csv的第0行有問題。 – 2015-03-18 22:02:39

您CSVRead沒有主要方法..電話更改爲CSVRead.read();

import java.util.Scanner; 
public class CSVMain{ 

    public static void main(String[] arg) throws Exception { 
     @SuppressWarnings("resource") 
     Scanner in = new Scanner(System.in); 
     int userChoice; 
     boolean quit = false; 
     do { 
     System.out.println("Please choose an option using 1 - 4");      //print text to screen 
     System.out.println("------------------------------------");      //print text to screen 
     System.out.println("1: Read 'input' CSV file");         //print text to screen 
     System.out.println("2: Calculate 'input' CSV file");       //print text to screen 
     System.out.println("3: Write calculation result to CSV file");     //print text to screen 
     System.out.println("4: Exit program");           //print text to screen 
      userChoice = in.nextInt();             //'in' equals integer 
      if (userChoice == 4)              //when '3' is input then... 
        quit = true;               //the program will now quit 
      else if (userChoice == 1)             //when '1' is input then... 
        CSVRead.read(); 
      else if (userChoice == 2); 
       //####################calculations go here#########################    
       //####################calculations go here######################### 
       //####################calculations go here######################### 
     } while (!quit); 
    } 
}

CSVRead.java

import java.io.BufferedReader; 
import java.io.FileNotFoundException; 
import java.io.FileReader; 
import java.io.IOException; 

public class CSVRead { 
    static void read() throws IOException { 
     String csvFileToRead = "profit.csv"; 
     BufferedReader br = null; 
     String line = ""; 
     String splitBy = ","; 

     try { 
      br = new BufferedReader(new FileReader(csvFileToRead)); 

      while ((line = br.readLine()) != null) { 
       String[] array = line.split(splitBy); 
       System.out.println("Equity & Bonds: [Instrument Type= " + array[0] + " , Name=" + array[1] + " , Quantity=" + array[2] 
           + " , Buy=" + array[3] + " , Sell=" + array[4] + /*" , Coupon=" + array[5] +*/ "]"); 
      } 

     } 
     catch (FileNotFoundException e) { 
      e.printStackTrace(); 
     } 
     catch (IOException e) { 
      e.printStackTrace(); 
     } 
     finally { 
      if (br != null) { 
       try { 
        br.close(); 
       } catch (IOException e) { 
        e.printStackTrace(); 
       } 
      } 
     } 
     System.out.println("Done reading CSV file"); 
    } 
}

輸出

Please choose an option using 1 - 4 
------------------------------------ 
1: Read 'input' CSV file 
2: Calculate 'input' CSV file 
3: Write calculation result to CSV file 
4: Exit program 
1 
Equity & Bonds: [Instrument Type= instrument_type , Name=name , Quantity=quantity , Buy=buy_price , Sell=sell_price] 
Equity & Bonds: [Instrument Type= Equity , Name=AAA , Quantity=123 , Buy=1.01 , Sell=1.10] 
Equity & Bonds: [Instrument Type= Equity , Name=BBBB , Quantity=3 , Buy=1.05 , Sell=1.01] 
Equity & Bonds: [Instrument Type= Bond , Name=CCC , Quantity=3 , Buy= , Sell=] 
Equity & Bonds: [Instrument Type= Equity , Name=AAA , Quantity=12 , Buy=1.11 , Sell=1.13] 
Equity & Bonds: [Instrument Type= Bond , Name=DD , Quantity=3 , Buy= , Sell=] 
Done reading CSV file

ALTERNATIVEL Y，在CSVRead

class public class CSVRead { 
    static void main() throws IOException {

重命名read方法main然後調用它就像你在CSVMain類

來源

2015-03-18 21:44:01 adrCoder

剛試過用我的實際主類運行這個，我仍然得到同樣的例外，我超出了界限。這非常令人沮喪。我的主要課程是通過設置其他菜單來調用此方法。 – 2015-03-18 21:47:34

你的主要課程是什麼？你顯然是在做別的錯誤，因爲我剛剛運行它，它按我告訴過的那樣工作 – adrCoder 2015-03-18 21:49:06

編輯第一篇文章與整個主 – 2015-03-18 21:50:10

數組索引超出範圍例外問題

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