Finding Correct exception to catch

Question

Which exception can i use to check if the input has the right number of "/" The input should be like DD/MM/YYYY

try{
                String str = text.getText();
                StringTokenizer st = new StringTokenizer(str);
                String DD = st.nextToken("/");
                String MM = st.nextToken("/");
                String YYYY = st.nextToken();
}
catch( ???){

}

Answer 1

You will find it in the javadoc of nextToken. It says it will throw a NoSuchElementException when there is no more token.

That said you should better not use the try/catch but test it using the hasMoreTokens method.

Answer 2

You can use Custom Exception for this but for that you need to declare method which validate your date (No of slashes).

Try Like this

   public class Demo
      {


  public static void main (String[] args) {

      try {
        new MyClass().metToValidate("01/12/2014");
          } catch (A e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
          }

      }

}
class A extends Exception{}


class MyClass{
      public void metToValidate(String dateText) throws A{


                if( dateText.charAt(2) == '/'&& dateText.charAt(5) == '/' )
                    System.out.println("DATE IS OK"); 

                else
                    throw new A();
      }
    }

Answer 3

The exception throws by nextToken is NoSuchElementException.

Answer 4

            String str = "12/21223";
            int counter = 0;
            for( int i=0; i<str.length(); i++ ) {
                if( str.charAt(i) == '/' ) {
                    counter++;
                } 
            }
            if(counter == 3){
                StringTokenizer st = new StringTokenizer(str);
                String DD = st.nextToken("/");
                String MM = st.nextToken("/");
                String YYYY = st.nextToken();
                System.out.println(str);
            }else{
                System.out.println("Exception");
            }