java try and catch..infinite loop

Question

I am having a problem with try and catch . My program is to insert three different strings name, address and phone number then I convert these three in to a single String using toString method.

I have problem with exception handling whenever I write a wrong choice (String or other data type) then catch works infinity times.

import java.util.ArrayList;
import java.util.Scanner;

public class mainClass {

  public static void main(String[] args) {
    Scanner input= new Scanner(System.in);
    ArrayList<String> arraylist= new ArrayList<String>();
    CreateFormat FormatObject = new CreateFormat();

    int choice;
    String phoneNumber;
    String name,address;
    String format="Empty";
    int x=1;
    int flag=0;
    do
    {
    try

    {   
    System.out.println("Enter your choice");
    System.out.printf("1:Enter new data\n2:Display data");
    choice=input.nextInt();
    switch (choice)
    {
    case 1:
    {
        System.out.println("Enter name  ");
        name=input.next();
        System.out.println("Enter phone number");
        phoneNumber=input.next();
        System.out.println("Enter address");
        address=input.next();
        format=FormatObject.toString(phoneNumber, name, address);
        arraylist.add(format);
        flag++;


    }
        break;
    case 2:
    {
        System.out.println("Name   Phone number   Address");
        System.out.println();
        for(int i=0;i<flag;i++)
        {   
        System.out.println(arraylist.get(i));

        }
    }
        break;
    }

}

 catch(Exception InputMismatchException){
System.out.println("Enter right choice");`
   }while(x==1);
}
}


//The format class ...//returns format for string

Answer 1

Your try and catch are not related to a loop, nor to your problem.

while(x==1)

is what you test on, yet you never change the value of x , so it will always remain 1, and thus the above check will always return true.

Answer 2

I think I now know what your problem actually is.

Simply adding input.nextLine() at the very beginning at your code will stop the input running havoc.

boolean wrongInput = false;
do {
   try {
       if (wrongInput) {
          input.nextLine();
          wrongInput = false;   
       }
       System.out.println("Enter your choice");
       [...]
   } catch (...) {
       wrongInput = true;
   }

should do the trick. However, please note that I noticed two errors in your program (which might be because I do not have the CreateFormat class of yours), (a) I cannot add a number to the address and (b) there is no option to stop the loop (which I strongly recommend - where you simply set x = -1 or something similar, better use a boolean to end the loop though).