Catching nullpointerexception in Java [closed]

Question

I tried using try-catch block to catch NullPointerException but still the following program is giving errors. Am I doing something wrong or is there any other way to catch NullPointerException in the following program. Any help is highly appreciated.

public class Circular_or_not  {      /**      * @param args      */     public static void main(String[] args)      {         // TODO Auto-generated method stub         try         {             LinkedListNode[] nodes = new LinkedListNode[10];                         for (int i = 0; i < 10; i++)              {                 nodes[i] = new LinkedListNode(i, null, i > 0 ? nodes[i - 1] : null);             }              // Create loop;             // nodes[9].next = nodes[3];             Boolean abc= Check_Circular(nodes[0]);             System.out.print(abc);         }         catch(NullPointerException e)         {             System.out.print("NullPointerException caught");         }      }      public static boolean Check_Circular(LinkedListNode head)      {                    LinkedListNode n1 = head;             LinkedListNode n2 = head;               // Find meeting point             while (n2.next != null)             {                  n1 = n1.next;                  n2 = n2.next.next;                  if (n1 == n2)                  {                      return true;                 }             }             return false;     }  } 

Answer 1

NullPointerException is a run-time exception which is not recommended to catch it, but instead avoid it:

if(someVariable != null) someVariable.doSomething(); else {     // do something else } 

Answer 2

As stated already within another answer it is not recommended to catch a NullPointerException. However you definitely could catch it, like the following example shows.

public class Testclass{      public static void main(String[] args) {         try {             doSomething();         } catch (NullPointerException e) {             System.out.print("Caught the NullPointerException");         }     }      public static void doSomething() {         String nullString = null;         nullString.endsWith("test");     } } 

Although a NPE can be caught you definitely shouldn't do that but fix the initial issue, which is the Check_Circular method.