Question

So, what I got is:

class BlahBlah
{
    public BlahBlah()
    {
        things = new ArrayList<Thing>();
    }

    public Thing[] getThings()
    {
        return (Thing[]) things.toArray();
    }

    private ArrayList<Thing> things;
}

In the other class I got:

for (Thing thing : someInstanceOfBlahBlah.getThings())
{
    // some irrelevant code
}

And the error is:

Exception in thread "main" java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to [LsomePackage.Thing;
at somePackage.Blahblah.getThings(Blahblah.java:10)

How can I solve this problem?

Answer 1

Try:

public Thing[] getThings()
{
    return things.toArray(new Thing[things.size()]);
}

The reason your original version doesn’t work is that toArray() returns Object[] and not Thing[]. You need to use the other form of toArray — toArray(T[]) — to get an array of Things.