使用类在java中创建对象数组

我正在做一个项目，我有一个文本文件，第一行是我需要的数组的大小，接下来的行有课程信息，顺序如下：dept，num，title。（例如，CSC 101 Basic Computing）我的代码符合要求，但当它运行数组中的第一个索引时，将成为默认索引（即无），因此文本文件中的最后一行不会被存储或打印。我想知道怎样才能纠正这个错误

import java.util.Scanner;
import java.io.*;

public class Organizer {

    public static void main(String[] args) {
        Scanner fileScanner = null;
        String file;
        File f = null;

        //Create a Do While loop in order to prompt the user for a input file
        //and then continue prompting if the file entered does not exist.

        do {
            try {

                System.out.print("What is the name of the input file? ");
                Scanner inputReader = new Scanner(System.in);
                file = inputReader.nextLine();
                f = new File(file);
                fileScanner = new Scanner(new File(file));

                //Catch the exception and tell the user to try again
            } catch (FileNotFoundException e) {

                System.out.println("Error scanning that file, please try again.");

            }
        } while (!f.exists());

        //Testing the Make Array Method
        //System.out.print(makeArray(fileScanner));

        //Testing the print Array Method
        printArray(makeArray(fileScanner));

    }

    public static Course[] makeArray(Scanner s) {

        int arraySize = s.nextInt();
        String title = "";
        String dept = "";
        int num = 0;
        Course[] a = new Course[arraySize];
        for (int i = 0; i < a.length; i++) {

            a[i] = new Course(dept, num, title);
            String oneLine = s.nextLine();
            Scanner lineReader = new Scanner(oneLine);
            while (lineReader.hasNext()) {

                dept = lineReader.next();
                a[i].setDept(dept);
                num = lineReader.nextInt();
                a[i].setNum(num);
                while (lineReader.hasNext()) {
                    title = title + lineReader.next() + " ";
                }
                a[i].setTitle(title);
            }
            title = " ";
        }
        return a;
    }


    public static void printArray(Course[] arr) {

        for (int i = 0; i < arr.length; i++) {

            System.out.println(arr[i].toString());
        }
    }
}

---

不要忘记你的光标在扫描仪中的每一时刻。

s.nextLine（）。它不会检查这是否是该行的最后一次输入

只需将代码修复为：

int arraySize = s.nextInt();
s.nextLine();

你的代码应该运行得很好

（也考虑更改<代码> A[i] .SiteTitle（title）；< /COD>到<代码> A[i] .SiteTitle（title .Times）；，因为在title的结尾总是留有一个空白空间）
 < P> NEXTIN方法不消耗新行字符。以下是一个有效的解决方案：

public static Course[] makeArray(Scanner s){

    int arraySize = s.nextInt();
    String title = "";
    String dept = "";
    int num = 0;
    Course[] a = new Course[arraySize];
    s.nextLine();
    for (int i = 0; i < a.length; i++){

        a[i] = new Course(dept, num, title);
            String oneLine = s.nextLine();
            Scanner lineReader = new Scanner(oneLine);

            while (lineReader.hasNext()){

                dept = lineReader.next();
                a[i].setDept(dept);
                num = lineReader.nextInt();
                a[i].setNum(num);
                while (lineReader.hasNext()){
                    title = title + lineReader.next() + " ";
                }
                a[i].setTitle(title);
            }
            title = " ";
    }   
return a;

publicstaticcourse[]makeArray（扫描器）{
int arraySize=s.nextInt（）；
字符串标题=”；
字符串dept=“”；
int num=0；
课程[]a=新课程[排列]；
s、 nextLine（）；
for（int i=0；i

}

public static Course[] makeArray(Scanner s){

    int arraySize = s.nextInt();
    String title = "";
    String dept = "";
    int num = 0;
    Course[] a = new Course[arraySize];
    s.nextLine();
    for (int i = 0; i < a.length; i++){

        a[i] = new Course(dept, num, title);
            String oneLine = s.nextLine();
            Scanner lineReader = new Scanner(oneLine);

            while (lineReader.hasNext()){

                dept = lineReader.next();
                a[i].setDept(dept);
                num = lineReader.nextInt();
                a[i].setNum(num);
                while (lineReader.hasNext()){
                    title = title + lineReader.next() + " ";
                }
                a[i].setTitle(title);
            }
            title = " ";
    }   
return a;