基本上我的程序采用文本文件并读取文件并将其拆分为2D数组（文本文件：http://pastebin.com/6ACSUL20）。我在命令行中传递了文本文件的名称。但是，当我运行我的程序时，我得到一个ArrayIndexOutOfBoundsException，这让我相信该程序没有正确拆分文本文件。将我指向包含Integer.parseInt(titanic[i][1])的每种方法。我们将不胜感激。
package testtitanic;
import java.io.FileNotFoundException;
import java.util.Scanner;
import java.io.File;
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
public class Titanic {
String[][] titanic;
public Titanic(String[] args){
try{
File text = new File(args[0]);
//turns the txt file into a string
String content = new Scanner(text).useDelimiter("\\Z").next();
//creates array and breaks up by new lines
String[] rows = content.split("\n");
// creates 2D array
this.titanic = new String[rows.length][];
// fills 2D array
for(int i = 0; i < rows.length; i++){
this.titanic[i] = rows[i].split("\\t");
}// end for loop
}// end try
catch(FileNotFoundException e){
System.out.println("Error" + e.getMessage());
}// end catch method
}// end fill method
public void menu(){
System.out.println("*******Welcome to the Titanic Statistical Application**************");
System.out.println("");
System.out.println("Enter the number of the question you want answered. Enter 'Q' to quit program:");
System.out.println("");
System.out.println("1. How many passengers were on the Titanic?");
System.out.println("2. What percent of passengers perished on the Titanic?");
System.out.println("3. What percent of passengers survived the sinking of the Titanic?");
System.out.println("4. What percentage of passengers survived for each of the three classes?");
System.out.println("5. What specific passengers who were less than 10 years old survived the sinking of the titanic?");
System.out.println("6. For each letter in the alphabet, how many passengers last names started with that letter?");
System.out.println("7. How many females and males were on the Titanic?");
System.out.println("Q. Quit the program");
}
public void getPassengerNumber(){
int num = titanic.length;
System.out.println("There were " + num + " passengers on the Titanic.");
}//end method
public void getPerishedPercent(){
int num = titanic.length;
int perished = 0;
for(int i = 0; i < num; i++){
int x = Integer.parseInt(titanic[i][1]);
if(x == 0){
++perished;
}// end if
}// end for
double percent = (perished / num) * 100;
System.out.println("The percentage perished on the Titanic is: " + percent);
}// end method
public void getPerishedSurvived(){
int num = titanic.length;
int survived = 0;
for(int i = 0; i < num; i++){
int x = Integer.parseInt(titanic[i][1]);
if(x == 1){
++survived;
}// end if
}// end for
double percent = (survived / num) * 100;
System.out.println("The percentage survived on the Titanic is: " + percent);
}// end method
public void getClassPercentage(){
int firstClass = 0;
int secondClass = 0;
int thirdClass = 0;
int num = titanic.length;
for(int i = 0; i < titanic.length; i++ ){
int x = Integer.parseInt(titanic[i][0]);
if(x == 1){
++firstClass;
}// end iff
if(x == 2){
++secondClass;
}
if(x == 3){
++thirdClass;
}
}// end for
double firstpercent = (firstClass / num) * 100;
double secondpercent = (secondClass / num) * 100;
double thirdpercent = (thirdClass / num) * 100;
System.out.println("Percent Survived for Firstclass is: " + firstpercent);
System.out.println("Percent Survived for Secondclass is: " + secondpercent);
System.out.println("Percent Survived for ThirdClass is: " + thirdpercent);
}// end method
public void getAge() {
int num = titanic.length;
int age = 0;
for(int i = 0; i < num; i++ ){
int x = Integer.parseInt(titanic[i][4]);
if(x < 10){
System.out.println(titanic[i][2]);
}
}// end for loop
}// end method
public void getLetters(){
for(char a = 'A'; 'Z' <= a; a++ ){
int temp = 0;
for(int i = 0; i < titanic.length; i++){
char x = titanic[i][2].charAt(0);
if(x == a){
++temp;
}// end if
System.out.println(a + ": There are " + temp + " passengers that have this letter to start as their last name.");
}// end inner
} // end outer
}// end method
public void getGender(){
int male = 0;
int female = 0;
int num = titanic.length;
for(int i = 0; i < num; i++){
if(titanic[i][3].equals("female")){
++female;
}// end if
if(titanic[i][3].equals("male")){
++male;
}// end if
}// end for
System.out.printf("There were %d females and %d males on the titanic \n", male, female);
}// end method
}//end class Titanic
使用此类调用
package testtitanic;
import java.time.LocalTime;
import java.time.Duration;
import java.util.Scanner;
/**
*
* @author Joe
*/
public class TestTitanic {
/**
* @param args the command line arguments
*/
public static void main(String[] argv) {
LocalTime startTime = LocalTime.now();
Scanner input = new Scanner(System.in);
int y = 1;
Titanic data = new Titanic(argv);
while(y == 1){
data.menu();
char x = input.next().charAt(0);
switch (x){
case '1':
data.getPassengerNumber();
break;
case '2':
data.getPerishedPercent();
break;
case '3':
data.getPerishedSurvived();
break;
case '4':
data.getClassPercentage();
break;
case '5':
data.getAge();
break;
case '6':
data.getLetters();
break;
case '7':
data.getGender();
break;
case 'Q':
y = 0;
break;
default:
System.out.println("Please enter a valid input to exit, be sure to input a capital Q.");
}// end switch
}// end while loop
LocalTime endTime = LocalTime.now();
Duration timeElapsed = Duration.between(startTime,endTime);
double time = timeElapsed.toMillis() * 1000;
System.out.println("Thanks for running this program the total time elapsed is: " + time + " seconds");
}
}
答案 0 :(得分：0)
为我工作，但我在泰坦尼克号构造函数中硬编码了文件名。你确定你传给它一个文件名吗？
你可以发布堆栈跟踪吗？数组索引是否超出了argv的范围？
您无需猜测索引超出界限的位置。堆栈跟踪将告诉您确切的行。