java - 如何将一个文件拆分为多个数组，显示它们，并对某些数组进行计算

Question

我有一个问题，如何将文件的数据拆分为多个数组并对某些数组执行计算。就我而言，我需要读取飓风文件并在其自己的数组中打印出名称、年份、类别、压力和风速，然后找到类别、压力和风速的平均值，然后找出飓风的数量特定类别，例如类别 1:26。我不知道该怎么做。我使用了 in.nextInt() 但我假设它会打印出文件行中的所有数字，然后继续到下一个，依此类推，因为当我运行程序时，出现错误。我怎样才能写出这样的程序呢？任何帮助将不胜感激。下面是我尝试读取的文件。

hurcdata2.txt:

1980 Aug    945 100 Allen           2
1983 Aug    962 100 Alicia          2
1984 Sep    949 100 Diana           2
1985 Jul    1002    65  Bob         1
1985 Aug    987 80  Danny           1
1985 Sep    959 100 Elena           2
1985 Sep    942 90  Gloria          1
1985 Oct    971 75  Juan            1
1985 Nov    967 85  Kate            1
1986 Jun    990 75  Bonnie          1
1986 Aug    990 65  Charley         1
1987 Oct    993 65  Floyd           1
1988 Sep    984 70  Florence        1
1989 Aug    986 70  Chantal         1
1989 Sep    934 120 Hugo            3
1989 Oct    983 75  Jerry           1
1991 Aug    962 90  Bob         1
1992 Aug    922 145 Andrew          4
1993 Aug    960 100 Emily           2
1995 Aug    973 85  Erin            1
1995 Oct    942 100 Opal            2
1996 Jul    974 90  Bertha          1
1996 Sep    954 100 Fran            2
1997 Jul    984 70  Danny           1
1998 Aug    964 95  Bonnie          1
1998 Sep    987 70  Earl            1
1998 Sep    964 90  Georges         1
1999 Aug    951 100 Bret            2
1999 Sep    956 90  Floyd           1
1999 Oct    987 70  Irene           1
2002 Oct    963 80  Lili            1
2003 Jul    979 80  Claudette       1
2003 Sep    957 90  Isabel          1
2004 Aug    972 70  Alex            1
2004 Aug    941 130 Charley         4
2004 Aug    985 65  Gaston          1
2004 Sep    960 90  Frances         1
2004 Sep    946 105 Ivan            2
2004 Sep    950 105 Jeanne          2
2005 Jul    992 65  Cindy           1
2005 Jul    930 130 Dennis          4
2005 Jul    929 135 Emily           4
2005 Aug    975 85  Irene           1
2005 Aug    902 150 Katrina         4
2005 Sep    960 100 Maria           2
2005 Sep    979 80  Nate            1
2005 Sep    976 80  Ophelia         1
2005 Sep    985 70  Phillipe        1
2005 Sep    897 150 Rita            4
2005 Sep    979 70  Stan            1
2005 Sep    987 65  Vince           1
2005 Sep    882 150 Wilma           4
2005 Sep    960 100 Beta            2
2005 Sep    979 75  Epsilon         1
2006 Aug    995 65  Ernesto         1
2006 Sep    972 80  Florence        1
2006 Sep    955 105 Gordon          2
2006 Sep    954 110 Helene          2
2006 Sep    985 75  Isaac           1

下面是我编写的程序代码，但无法正确运行

飓风2.java:

import java.io.File;
import java.util.Scanner;
import java.io.IOException;
import java.util.ArrayList;

public class Hurricanes2{

public static void main(String args[]) throws IOException{

    // create Scanner inFile
    File filename = new File("/Users/timothylee/hurcdata2.txt");

    int i = 0;

    int[] values = new int[i];
    String[] HurrNames = new String[i];

    Scanner inFile = new Scanner(filename);

    while(inFile.hasNext()){
        values[i] = inFile.nextInt();
        HurrNames[i] = inFile.next();
        i++;
        System.out.println(values[i]);
        System.out.println(HurrNames[i]);
    }
    inFile.close();
}
}

当我运行它时我得到这个:

run:
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0
at Hurricanes2.main(Hurricanes2.java:22)
Java Result: 1
BUILD SUCCESSFUL (total time: 1 second)

Answer 1

我将使用数组列表并解析每一行。目前您正在创建没有长度的数组。数组无法更改其大小，但数组列表可以。所以像这样:

List<Integer> year = new ArrayList<Integer>;
List<String> month = new ArrayList<String>;
// etc...

while((String line = inFile.nextLine()) != null){ // read file line by line
    String[] values = line.split(" ").trim(); // split line and add to string array
    year.add(Integer.parseInt(values[0])); // add to list as an Integer
    month.add(values[1]); // add to list
}