您的循环正在等待一个扫描器的行，但从另一个Scanner阅读行（因此是无限循环）。这一

while (lineScan.hasNext()) {
    inter= scan.next();

应该是这样的

while (lineScan.hasNext()) {
    inter= lineScan.next();

您不需要两个扫描仪对象来实现输出，这将为您工作

scan= new Scanner(System.in); //scan from the keyboard
System.out.println("Enter a line of text: ");
input=scan.nextLine(); //scan the line of text

System.out.println(input.toLowerCase());
scan.close();

我推荐一个不同的方法：

import java.util.*;
public class something
  {
      static Scanner reader=new Scanner(System.in);
      public static void main(String[] args)
      {
          System.out.println("type something (string)");
          String text = reader.next();  // whatever the user typed is stored as a string here
          System.out.println(text);

          System.out.println("type something (int)");
          int num = reader.nextInt();  // whatever the user typed is stored as an int here
          System.out.println(num);

          System.out.println("type something (double)");
          double doub = reader.nextDouble(); // whatever the user typed is stored as double here
          System.out.println(doub);
        }
    }

这是我如何获取用户输入的一些示例代码。