Question

JAVA Problem Description:

For this assignment, you will be writing your own exception class and you will handle run-time exceptions resulting from one particular input situation.

Specifics:

1) Design and implement a program that has an exception class called StringTooLongException, designed to be thrown when a string is discovered that has too many characters in it.

2) In the main driver of the program (call this class MyExceptionTest), read strings from the user until the user enters “DONE”. If a string is entered that has too many characters (use 20 or more), throw the exception.

3) The exception is to be caught and handled by having an appropriate message output to the screen. Once done, the program continues by processing more strings.

try using string.length

Answer 1

Follow the below java code to write user defined exception and how to call them

User defined Exception Class StringTooLongException:

import java.util.*;
class StringTooLongException extends Exception // Exception is the parent class for all type of exceptions
{
public StringTooLongException(String s)
{
super(s);
}
public String toString(){
return ("Too many Characters in the given string") ; //this is user defined message you can replace with your own
}
}

// Main class MyExceptionTest:
public class MyExceptionTest{
public static void main(String [] args){
String str = "";
Scanner sc = new Scanner(System.in);
for(int i=1;i>0;i++){ //this loop got terminated when it get DONE string from user
str = sc.next();
if(str.equals("DONE")){
break;
}
  
try{
if(str.length()>=20)

// .length() function gives the string length

throw new StringTooLongException(str);

//here the user defined exception is get called

/* you can write your own code when the string is less than 20 characters of length */

}
catch(StringTooLongException exception){ // user defined message gets returned from the user defined exception
System.out.println(exception);
}
}
}
}