获取此错误 -> Java 中线程“main”java.util.InputMismatc

Question

我收到错误：Exception in thread "main" java.util.InputMismatchExceptionat java.base/java.util.Scanner.throwFor(Scanner.java:939)at java.base/java.util.Scanner.next(Scanner.java:1594)at java.base/java.util.Scanner.nextInt(Scanner.java:2258)at java.base/java.util.Scanner.nextInt(Scanner.java:2212)at com.raghuvamsha.Main.main(Main.java:24)在我的程序中： 1. 主类。import java.util.Scanner;public class Main {public static void main(String[] args) {    // write your code here    // Using Scanner for Getting Input from User    System.out.println("\tMAIN MENU:\n" +            "\t\t1) Add new member record\n" +            "\t\t2) Modify existing member record\n" +            "\t\t3) Delete member record\n" +            "\t\t4) Display all member records\n" +            "\t\t5) Search for a particular member record\n" +            "\t\t6) Exit");    int a = 0;    while(a!=6) {        Scanner reader = new Scanner(System.in);        a = reader.nextInt();        System.out.println("You entered integer " + a);        if(a==1){            AddNewMember anm = new AddNewMember();            anm.openFile();            anm.addRecords();            anm.closeFile();        }    }   }}