我正在编写一个程序,它接受来自文件的输入并打印城市列表及其降雨量。我在确定需要的阵列长度和城市降雨数据的扫描仪上遇到问题。
我不断收到此异常
在 java.util.Scanner.next(Scanner.java:1530) 在 java.util.Scanner.throwFor(Scanner.java:909) 在 java.util.Scanner.nextInt( Scanner.java:2160) 在 java.util.Scanner.nextInt(Scanner.java:2119) 在 BarChart.main(BarChart.java:29)
这是我的代码:
import java.util.Scanner;
public class BarChart
{
public static void main (String[] args)
{
//create scanner
Scanner scan = new Scanner(System.in);
//create size variable
int size = scan.nextInt();
//create arrays to hold cities and values
String[] cities = new String [size];
int[] values = new int [size];
//input must be correct
if (size > 0)
{
//set values of cities
for(int i=0; i<size; i++)
{
cities[i] = scan.nextLine();
}
//set values of the data
for(int j=0; j<size; j++)
{
values[j] = scan.nextInt();
}
//call the method to print the data
printChart(cities, values);
}
//if wrong input given, explain and quit
else
{
explanation();
System.exit(0);
}
}
//explanation of use
public static void explanation()
{
System.out.println("");
System.out.println("Error:");
System.out.println("Input must be given from a file.");
System.out.println("Must contain a list of cities and rainfall data");
System.out.println("There must be at least 1 city for the program to run");
System.out.println("");
System.out.println("Example: java BarChart < input.txt");
System.out.println("");
}
//print arrays created from file
public static void printChart(String[] cities, int[] values)
{
for(int i=0; i<cities.length; i++)
{
System.out.printf( "%15s %-15s %n", cities, values);
}
}
}