JAVA EE: Java Tutorial : Java Exception handling (catch block)

Monday, 20 June 2016

Java Tutorial : Java Exception handling (catch block)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=yFNCrAbHx7E&list=UUhwKlOVR041tngjerWxVccw

Click the below Image to Enlarge

Java Tutorial : Java Exception handling (catch block)

ExceptionDemo1.java

public class ExceptionDemo1
{
    public static void main(String[] args)
    {
        String firstName = null;

        // May throw an Exception
        System.out.println(firstName.length());

        String lastName = "Peter";
        String fullName = firstName + lastName;
        System.out.println("fullName = " + fullName);
    }

}

Output

Exception in thread "main" java.lang.NullPointerException
    at ExceptionDemo1.main(ExceptionDemo1.java:8)

ExceptionDemo2.java

public class ExceptionDemo2
{
    public static void main(String[] args)
    {
        String firstName = null;
        
        try
        {
          // May throw an Exception 
          System.out.println(firstName.length());
        }
        catch(NullPointerException nullPointerException)
        {
            System.out.println("String is null");
        }
        
        String lastName = "Peter";
        String fullName = firstName+lastName;
        System.out.println("fullName = "+fullName); 
    }

}