Iterating in a collection (LIST or MAP)

[karimkhan pathan]

Hi ranchers ,

I'm getting this [[shipmentId=20390, facilityId=10070, shipGroupSeqId=00001]] collection from a service , can you please tell me how to iterate throw this collection . I need to get the shipmentid .

[Rob Spoor]

What is that structure? A String? A List of Lists? A List of arrays? A List of Maps?

[karimkhan pathan]

HI Rob,

Even I'm also trying to get the structure .
I think its a list in list structure ,list thought it would be a list in list with a map as element.

[Seetharaman Venkatasamy]

karimkhan pathan wrote: it would be a list in list with a map as element.

probably it is not! . Map elements always display surrounding by "{}" . so first find out what types are that by using getClass() . i think it should be *list of list of some thing* . if yes just iterate through by using 2 for loops.

[karimkhan pathan]

Hi Seetharaman ,

your correct ,its not a map its a list in list only .

Thanks a lot ranchers ..

[Seetharaman Venkatasamy]

You are welcome

[Rob Spoor]

Until you find out it's going to be difficult, so you'll need to analyze first. Using getClass(), instanceof and casting you can already find out a lot. A recursive call may be quite useful:

public static void analyze(Object object, String indent)
{
    if (object == null)
    {
        System.out.println(indent + "null");
        return;
    }
    Class<?> cls = object.getClass();
    System.out.println(indent + cls.getName());
    if (object instanceof Collection)
    {
        if (object instanceof List)
        {
            System.out.println(indent + "List:");
        }
        else if (object instanceof Set)
        {
            System.out.println(indent + "Set:");
        }
        else
        {
            System.out.println(indent + "Collection:");
        }
        for (Object o: (Collection)object)
        {
            analyze(o, indent + "  ");
        }
    }
    else if (object instanceof Map)
    {
        System.out.println(indent + "Map:");
        for (Map.Entry<?,?> entry: ((Map)object).entrySet())
        {
            // analyzing of keys / values is skipped
            System.out.println(indent + "  " + entry);
        }
    }
    else if (cls.isArray())
    {
        System.out.println(indent + "Array of " + cls.getComponentType().getName() + ":");
        // use reflection
        int length = Array.getLength(object); //
        for (int i = 0; i < length; i++)
        {
            Object o = Array.get(object, i);
            analyze(o, indent + "  ");
        }
    }
    else
    {
        System.out.println(indent + cls.getName() + ": " + object);
    }
}

The indentation is there to make it easier for you to see the full structure. The initial call uses an indent of "".

[karimkhan pathan]

Thanks Rob , It will help me .

[Rob Spoor]

You're welcome.