Required more explantion on exmaple given in Thread.

[kaushik vira]

 
public class HI{

     public static void main(String args[]) throws Throwable {
          try{
               getMe();
          }catch(ArithmeticException ae){
               System.out.print(1);
          }catch(ArrayIndexOutOfBoundsException ae){
               System.out.print(2);
          }catch(NullPointerException ae){
               System.out.print(3);
          }catch(RuntimeException ae){
               System.out.print(4);
          }catch(Exception ae){
               System.out.print(5);
          }
     }

     public static void getMe()throws ArithmeticException{
          if(true)
        	 throw new NullPointerException();
          System.out.println("hello");
          throw new ArrayIndexOutOfBoundsException();
     }

}

   

Here

 

 if(true)
        	 throw new NullPointerException();
  

Always thought null Pointer exception. still compiler is not taking any objection at compile time. Can any buddy explain this?

[Bob Wheeler]

kaushik vira wrote:

 
Here 
[code] 

 if(true)
        	 throw new NullPointerException();
  

Always thought null Pointer exception. still compiler is not taking any objection at compile time. Can any buddy explain this?

No reason for the compiler to complain. We are talking about unchecked exceptions here. The handle and declare rule is only for checked exceptions.

cheers
Bob

[Bob Wheeler]

[deleted: double post]

[sweety sinha]

 public static void main(String args[]) throws Throwable {   
          try{   
               getMe();   
          }catch(ArithmeticException ae){   
               System.out.print(1);   
          }catch(ArrayIndexOutOfBoundsException ae){   
               System.out.print(2);   
          }catch(NullPointerException ae){   
               System.out.print(3);   
          }catch(RuntimeException ae){   
               System.out.print(4);   
          }catch(Exception ae){   
               System.out.print(5);   
          }   
     }   
  
     public static void getMe()throws ArithmeticException{   
          if(true)   
             throw new NullPointerException();  
           //   System.out.println("hello");  say line 1
            throw new ArrayIndexOutOfBoundsException();   
             System.out.println("hello"); //1
     }   
  
}   

if line 1 is sifted to new position then it gives compilation error. But when it is at its original position why it is not giving error?

thanks in advance

[Ankit Garg]

Well when line 1 is at its original position, then there's a if condition there. So the compiler will think that NullPointerException may or may not be thrown. But if you move it below the other throw clause, then it definitely becomes unreachable, there's no way that control could reach the next statement to that throw statement. That's why the compiler complaints that the statement is unreachable. I know that the if condition will always be true so the NullPointerException will always be thrown, but the compiler for some reasons ignores that...

[kaushik vira]

I got the above point.. but my expectation here was, to get some internals of java compiler.. how it`s handling this type of conditions. Can can buddy elaborate it.