arraylist java上的IndexOutOfBoundsException

Question

I'm looking for the equivalent word in the database by the ContextQuery method, and when a equivalent word is null the program must try to use the next index from words and add it up to the current to make it a two word, if the two word is still null the program will make it a three word looking for the next 2 value, the equivalent is now being printed in console but i have the error IndexOutOfBoundsExpection after running

        for (int i = 0; i < words.size(); i++){
        temp = QueryWithContext.query(words.get(i));
            if((temp == null || temp.isEmpty()) && words.size() >= i+1)
            {
            QueryWithContext.query(words.get(i)+" "+words.get(i+1));
            temp = QueryWithContext.query(words.get(i)+" "+words.get(i+1));
            System.out.println("1st if");
                if((temp == null || temp.isEmpty()) && words.size() >= i+2)
                    {
                    temp = QueryWithContext.query(words.get(i)+" "+words.get(i+1)+" "+words.get(i+2));
                    }
                    else
                    {
                        temp = words.get(i);
                    }

            }



            System.out.println(temp);

Answer 1

if((temp == null || temp.isEmpty()) && words.size() >= i+1)

must be

if((temp == null || temp.isEmpty()) && words.size() > i+1)

otherwise

words.get(i+1)

throws the IndexOutOfBoundsExpection.

Answer 2

The problem is most likely in this line: temp = QueryWithContext.query(words.get(i)+" "+words.get(i+1)+" "+words.get(i+2)); . You are looping until i is less than the size of words , so i will range from 0 to n - 1 .

The problem is that in your code, you keep going till i + 2 (and previously, i + 1 ). This is what is most likely causing your error. To fix this, see if you can do the following: for (int i = 0; i < (words.size() - 2); i++){

Alternatively, do as @Uli recommends.