The hashtable elements' order is changed after JSONParser in multilist under Android device only

[Pai Peng]

Hello CN1,

now I have noticed one problem on my Samsung device with the hashtable.

The app receives JSON object from server. I use JSONParser to get a Hashtable object. Then using the following code to create a vector:

Enumeration enumeration = trashHotspots.elements();

                   while (enumeration.hasMoreElements()) {

                       Hashtable temp = (Hashtable)(enumeration.nextElement());

                       temp.put("abc", temp.get("abc"));

                       

                       owner.downloadImage((String)temp.get("photo_id"), v.size());

                       v.addElement(temp);

                   }

The vector is used for displaying in a Multilist.

The server sends the elements with desc order in JSON. But on Android device, the order (by id) in Multilist is changed: like 51->49->50->47->48->45....

But by testing on simulator and iPhone, the order is correct:51->50->49->48->47->46...

Do I make any mistake here?

Regards,

Pai

[Steve Hannah]

Hash tables have no order and JSON parsers do not preserve order of keys when parsing objects.  If order is important change the structure to an array of objects rather than just an object.

Steve

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Steve Hannah

Web Lite Solutions Corp.

[Pai Peng]

Hello Steve,

Thanks for your help.

I have to sort them in Vector. And it works fine now also on Android.

Regards,

Pai

On Monday, July 22, 2013 5:10:30 PM UTC+2, shannah wrote:

Hash tables have no order and JSON parsers do not preserve order of keys when parsing objects.  If order is important change the structure to an array of objects rather than just an object.

Steve

On Monday, July 22, 2013, Pai Peng wrote:

Hello CN1,

now I have noticed one problem on my Samsung device with the hashtable.

The app receives JSON object from server. I use JSONParser to get a Hashtable object. Then using the following code to create a vector:

Enumeration enumeration = trashHotspots.elements();

                   while (enumeration.hasMoreElements()) {

                       Hashtable temp = (Hashtable)(enumeration.nextElement());

                       temp.put("abc", temp.get("abc"));

                       

                       owner.downloadImage((String)temp.get("photo_id"), v.size());

                       v.addElement(temp);

                   }

The vector is used for displaying in a Multilist.

The server sends the elements with desc order in JSON. But on Android device, the order (by id) in Multilist is changed: like 51->49->50->47->48->45....

But by testing on simulator and iPhone, the order is correct:51->50->49->48->47->46...

Do I make any mistake here?

Regards,

Pai

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To view this discussion on the web visit https://groups.google.com/d/msgid/codenameone-discussions/878da70a-b3d3-4151-a004-191642d9daf0%40googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.