使用hasNextLine（）但仍然获得java.util.NosuChelementException：未找到行

Question

我正在做一个编程项目，并不断得到如下所示的错误。

Exception in thread "main" java.util.NoSuchElementException: No line found
    at java.util.Scanner.nextLine(Scanner.java:1585)
    at ArrayPhoneDirectory.loadData(ArrayPhoneDirectory.java:42)
    at ArrayPhoneDirectoryTester.main(ArrayPhoneDirectoryTester.java:18)

 public void loadData (String sourceName){
Scanner read = new Scanner(sourceName);

while (read.hasNextLine()) {
    String name = read.nextLine();
    String telno = read.nextLine(); //ArrayPhoneDirectory Line 42
    add(name, telno);
  }
 }

关联文本文件

John
123
Bill
23
Hello
23455
Frank
12345
Dkddd
31231

Answer 1

hasNextLine()

将只检查一个新行。只检查一行就不能读两行。

如果您必须连续读取记录，那么您可以

public void loadData (String sourceName){
    Scanner read = new Scanner(sourceName);
    int i = 1;

    while (read.hasNextLine()) {
        if(i%2 != 0)
            String name = read.nextLine();
        else
            String telno = read.nextLine(); //ArrayPhoneDirectory Line 42
        add(name, telno);
        i++;
    }
}