So I'm trying to make a simple program in Java that reads a text file (from a command line argument) and the user can check to see if a number they input is in the text file.
File inputFile = new File(args[0]);
Scanner scanman = new Scanner(inputFile); //Scans the input file
Scanner scanman_2 = new Scanner(System.in); //Scans for keyboard input
int storage[] = new int[30]; //Will be used to store the numbers from the .txt file
for(int i=0; i<storage.length; i++) {
storage[i]=scanman.nextInt();
}
System.out.println("WELCOME TO THE NUMERICAL DATABASE"+
"\nTO CHECK TO SEE IF YOUR NUMBER IN THE DATABASE"+
"\nPLEASE ENTER IT BELOW! TO QUIT: HIT CTRL+Z!");
while(scanman_2.hasNext()){
int num_store = scanman_2.nextInt();
boolean alert = false;
for (int i=0; i<storage.length; i++) {
if(storage[i]==num_store){
alert=true;
}
}
if (alert) {
System.out.println("Yep "+num_store+" is in the database\n");
}
else {
System.out.println("Nope, "+num_store+" is not in the database\n");
}
}
System.out.println("See ya!");
}
}
Everytime I attempt to run it I keep getting:
Exception in thread "main" java.util.NoSuchElementException
at java.util.Scanner.throwFor(Scanner.java:907)
at java.util.Scanner.next(Scanner.java:1530)
at java.util.Scanner.nextInt(Scanner.java:2160)
at java.util.Scanner.nextInt(Scanner.java:2119)
at Database.main(Database.java:17)
I've done a program similar to this and had no problems. Does anyone know what I'm doing wrong?
You are repeatedly calling nextInt()
, but not testing to see if there is a next int. Change this
for(int i=0; i<storage.length; i++) {
storage[i]=scanman.nextInt();
}
to this
for(int i=0; i<storage.length && scanman.hasNext(); i++) {
storage[i]=scanman.nextInt();
}
You'll need to determine if this is acceptable given your requirements, and if not, figure out why storage.length and the number of int-inputs are different than you expect.