how to define user defined exception in java code example

Example 1: java define custom exception

public class CustomException extends Exception { 
    public CustomException(String errorMessage) {
        super(errorMessage);
    }
}

Example 2: java user defined exception example

class InvalidAgeException extends Exception{  
 InvalidAgeException(String s){  
  super(s);  
 }  
}  
class TestCustomException1{  
  
   static void validate(int age)throws InvalidAgeException{  
     if(age<18)  
      throw new InvalidAgeException("not valid");  
     else  
      System.out.println("welcome to vote");  
   }  
     
   public static void main(String args[]){  
      try{  
      validate(13);  
      }catch(Exception m){System.out.println("Exception occured: "+m);}  
  
      System.out.println("rest of the code...");  
  }  
} 

Output:Exception occured: InvalidAgeException:not valid
       rest of the code...