Exception in thread "main" java.lang.NullPointerException
at Test1.main(Test1.java:14)

public class Test1 {
public static void myMethod(int i)
{
    System.out.println("calling @"+ i+"time");
}
public static void main(String arg [])
{
for(int i = 0;i<=999;i++)
{
    Test1 obj[] = null;
    obj[i] = new Test1();
    obj[i].myMethod(i);

}
}
}

Test1 obj[] = new Test1[1000];

for(int i = 0;i<=999;i++)
{
    //Test1 obj[] = null; // <----------- don't want this here

Test1 obj[] = new Test1[1000];