子字符串-StringIndexOutOfBounds异常Java

Question

I've been working on a program to collect data from a file and do some stuff to it (as evident in the code and pseudocode) however I'm having difficulty getting each element of the string into the right array. A line from a file looks like this:

1980 Aug    945 100 Allen

I'm wanting to use the substring method because that'd be the easiest in my opinion. Is there a better way of doing it? Here's my code thus far. Where does the problem lie exactly, and how should I fix it? Thanks! :)

import java.util.Scanner;
import java.io.File;
import java.io.IOException;
import java.lang.String; 
public class Hurricanes2
{

public static void main(String [] args) throws IOException 
{
int counter = 0;
String [] token = new String[1000];

String [] tokenElements = new String[128];
String [] hurricaneYear = new String[64];
String [] hurricaneName = new String[64];
String [] hurricaneMonth = new String[64];
int []  hurricaneCategory = new int[64];
double [] hurricanePressure = new double[64];
double tempKnots;
double knotsToMph; 
double [] hurricaneWindSpeed = new double[64];
double categoryAverage;
double pressureAverage;
double speedAverage; 
String headerData = "                          Hurricanes 1980 - 2006\n\n Year         Hurricane       Category        Pressure(MB)        Wind Speed     (MPH)\n========================================================================";
Scanner in = new Scanner(System.in);
Scanner inFile = new Scanner(new File("hurcData2.txt"));
System.out.println(headerData);

/**---Use for-each (line:token) 
 * Parse for year - > year array
 * parse for name - > name array
 * parse for knots - > tempKnots
 * knotsToMph = tempKnots  * 1.15078
 * hurricaneWindSpeed[counter] = knotsToMph
 *  enter if-else to calculate category (hurricaneCategory [] = 1,2,3,4, or 5):
 *      74-95 cat1 
 *      96-110 cat2
 *      111 - 129 cat3
 *      130-156 cat4
 *      157 or higher cat 5
 * 
 * 
 */
 while(inFile.hasNextLine()){

        token[counter] = inFile.nextLine();
        String tempToken = token[counter]; 
        hurricaneYear[counter] = tempToken.substring(0, 3);
        hurricaneMonth[counter] = tempToken.substring(6, 8);
        hurricanePressure[counter] = Double.parseDouble(tempToken.substring(10, 12));
        hurricaneWindSpeed[counter] = Double.parseDouble(tempToken.substring(14, 16));
        hurricaneName[counter] = tempToken.substring(17);


        counter++;


   }
System.out.print("Lines: " + counter);
}
}

Answer 1

You could probably do something like this:

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;







public class test {

    public void converter(String[] stringArray) {


        int counter = 0;
        String [] token = new String[1000];
        String [] tokenElements = new String[128];
        String [] hurricaneYear = new String[64];
        String [] hurricaneName = new String[64];
        String [] hurricaneMonth = new String[64];
        int []  hurricaneCategory = new int[64];
        double [] hurricanePressure = new double[64];
        double tempKnots;
        double knotsToMph; 
        double [] hurricaneWindSpeed = new double[64];
        double categoryAverage;
        double pressureAverage;
        double speedAverage; 
        String headerData = "                          Hurricanes 1980 - 2006\n\n Year         Hurricane       Category        Pressure(MB)        Wind Speed     (MPH)\n========================================================================";
        Scanner in = new Scanner(System.in);
        Scanner inFile = null;
        try {
            inFile = new Scanner(new File("hurcData2.txt"));
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }



        while(inFile.hasNextLine()){

          String line = inFile.nextLine();
          String[] arrayOfString = line.split(" "); 




           }
        System.out.print("Lines: " + counter);
        }




        }

The issue with incompatible types is because you have to convert the Scanner object to a String. I did that in the while loop, so now while the scanner has a next line its going to turn that line into a string and split it on the spaces. You will have an array for all the values. Now you can perform your logic based on the position in the array.

Answer 2

You can split the string into arrays with regex:

    String s = "1980 Aug    945 100 Allen";
    Pattern p = Pattern.compile("\\s+");
    System.out.println(Arrays.toString(p.split(s)));

or using the String.split method:

    System.out.println(Arrays.toString(s.split("\\s+")));

output:

[1980, Aug, 945, 100, Allen]
[1980, Aug, 945, 100, Allen]

Answer 3

The title of the question lists index out of bounds exception, but it does not say if it is StringIndexOutOfBoundsException or ArrayIndexOutOfBoundsException.

You read the lines into an array that is defined to hold 1000 elements, but then put the parsed pieces of the string into arrays that are only defined to hold 64 elements.

It could be that your parsing logic is OK but the array's are getting over filled.