Implementing Graph in Java, getting raw type error

Question

I'm trying to implement a Graph as an adjacency list, with the code below. I'm getting a raw type error on line 9.

Edit: Just want to clarify, I get an unchecked/unsafe operation error, then when I compile with Xlint, I get the raw type error.

import java.util.LinkedList;

public class AdjListGraph{
    private int vertices;
    private LinkedList<Integer>[] AdjList;

    public AdjListGraph(int v){
        this.vertices = v;
        AdjList = (LinkedList<Integer>[]) new LinkedList[v];
        for (int i = 0; i < v; i++){
            AdjList[i] = new LinkedList<Integer>();
        }
    }

Sorry should be line 9, this is the problematic line "AdjList = (LinkedList<Integer>[]) new LinkedList[v];". I'm compiling it in the command line. — user3002315
– user3002315, Commented Dec 6, 2016 at 1:37
LinkedList does not give great performance for random access. See stackoverflow.com/questions/10656471/… — dnault
– dnault, Commented Dec 6, 2016 at 1:40
Possible duplicate of How to create a generic array in Java? — Tim Biegeleisen
– Tim Biegeleisen, Commented Dec 6, 2016 at 1:45

Community · Accepted Answer · 2017-05-23 12:08:42Z

1

There's unsafe typecast in line 9.
Do not mix arrays and generics: LinkedList<Integer>[] is a bad smell. And that's the real problem. You can't have arrays of generic classes. Java simply doesn't support it. Read more in Q: How to create a generic array in Java?.

edited May 23, 2017 at 12:08

CommunityBot

11 silver badge

answered Dec 6, 2016 at 2:20

naXa stands with Ukraine

38.7k25 gold badges208 silver badges279 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

user3002315 Over a year ago

So should I use a collection instead?

Collectives™ on Stack Overflow

Implementing Graph in Java, getting raw type error

1 Answer 1

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related