Java Question How to convert Object to Map?

[adolleschal]

I have a Library which returns an Array of Objects, and now i want to convert this array to a Map. In Java i could simply do

Map<String,String> object = (Map<String,String>) myObject[y];

but how can i do something like that in BA4?

Thanks.

Best regards
Andreas

 

[Erel]

You will need to write:

Dim m As Map
m = YourObject

 

[adolleschal]

Thank you. That was my first idea how to do that, but when I code that i get the Error:

java.lang.ClassCastException: java.util.HashMap

Whats wrong?

Best regards
Andreas

 

[Erel]

I'm moving this question to the libraries development section.

Basic4android Maps are not regular HashMaps (as HashMaps do not allow you to retrieve items based on the index).
You will need to reference Core.jar and use Basic4android Map (or the internal MyMap) instead of a HashMap.

 

[adolleschal]

Where do i find MyMap? I cannot use BA4 Map because it collides with the Android Map Class.

 

[adolleschal]

OK, found it already. Thanks

 

[Erel]

I cannot use BA4 Map because it collides with the Android Map Class.

You can use Map. You just need to make sure that to reference it with the package name (or to configure your imports to use the right package). By typing Map and pressing Ctrl + Space Eclipse should offer you to choose both maps.

 

[jaminben]

Hi all,

After a mamouth search this is the best thread that I've found that comes close to doing what I'm trying to do.

I have some data which I'd like to put into a Map (HashMap?)... the data would look something like:

myMap(Key, Array As Object(Value1, Value2, Value3)

or

myMap(1, Array As Object("Name", "Job", Bitmap)

So basically I need to create a map with a key and for that key to return 3 results (2 strings and a Bitmap).

The best that I can do is get it to semi work by returning an object which I then can't access to get the values inside that object.

How can I do this?

:sign0104:

 

[Erel]

Are you writing this code in a Java library?

 

[jaminben]

Are you writing this code in a Java library?

No, in Basic4Android.

 

[derez]

If I understand correctly -
You can define a type which has the three objects, and fill the map with objects of that type.
Getting an object from the map by the key, you can refer to each of its internal objects.

 

[jaminben]

If I understand correctly -
You can define a type which has the three objects, and fill the map with objects of that type.
Getting an object from the map by the key, you can refer to each of its internal objects.

Could you explain in a little more detail as I'm not understanding types all that well.

Ok, so I've worked out this so far:

Sub Process_Globals
Type personDetails(Name As String, Character As String, Profile As Bitmap)
End Sub

Sub JobDone (Job As HttpJob)

Dim pD As personDetails
         
pD.Profile = Job.GetBitmap
pD.Name = castNameDataStore.Get(Job)
pD.Character = characterNameDataStore.Get(Job)
         
castMapTest.Put("0", pD)

End Sub

Sub castListView_ItemClick (Position As Int, Value As Object)
Log("castMapTest: " & castMapTest.Get("0"))
End Sub

This returns:

castMapTest: [Character=Hot Girl, Profile=(Bitmap): 100 x 150, Name=9 - Carmen Electra, IsInitialized=false]

Now I just need to work out how to get the individual results (Character, Profile and Name).

 

[stefanobusetto]

Sub castListView_ItemClick (Position As Int, Value As Object)
Dim pD As personDetails
pD = castMapTest.Get("0")

Log("castMapTest: " & pD.Name)
End Sub

 

[jaminben]

Sub castListView_ItemClick (Position As Int, Value As Object)
Dim pD As personDetails
pD = castMapTest.Get("0")

Log("castMapTest: " & pD.Name)
End Sub

Thanks for that

Here's the last peice of my code just in case anyone else needs to see it for reference or can spot any errors.

Sub JobDone (Job As HttpJob)
   
   Select Job.JobName
      Case "castProfileImages"
   
         If Job.Success = True Then
         
            Dim pD As personDetails
            
            pD.Profile = Job.GetBitmap
            pD.Name = castNameDataStore.Get(Job)
            pD.Character = characterNameDataStore.Get(Job)
            
            castCollection.Put(castPersonIDStore.Get(Job), pD)
            
         Else
         
            Dim pD As personDetails
            
            pD.Profile = peoplePoster
            pD.Name = castNameDataStore.Get(Job)
            pD.Character = characterNameDataStore.Get(Job)
            
            castCollection.Put(castPersonIDStore.Get(Job), pD)

         End If
         
         castCountDown = castCountDown + 1
         
         If castCountDown = castPersonIDList.Size Then
         
            For i = 0 To castPersonIDList.Size - 1
               
               Dim pD As personDetails
               pD = castCollection.Get(castPersonIDList.Get(i))
               
               castListView.AddTwoLinesAndBitmap(pD.Name, pD.Character, pD.Profile)
         
            Next
         
         End If
         
   End Select
   
Job.Release

End Sub

 

[walterf25]

Hello gentlemen, i'm glad i found this thread, i have a similar issue, i'm wrapping a library in Eclipse and i have came across the need of converting a java.util.Map<String, Object> to B4A map, i'm not sure how to do this, I know i can convert a B4A map to a java.util.Map<String, Object> by doing something like this

Map.getObject();

but i need to do the opposite now, here's a snippet of the code i'm dealing with.

        public void UpdateRecord(BA ba, BasicDocumentRevision retrieved, Map map) throws DocumentException{
            MutableDocumentRevision update = retrieved.mutableCopy();
            java.util.Map<String, Object> json = retrieved.getBody().asMap();
            'I need to do something like map = json;
            'but obviously i get the famous error telling me i B4A map can not be cast to java.util.hashmap
            update.body = DocumentBodyFactory.create(map.getObject());
            ds.updateDocumentFromRevision(update);
        }

Any thoughts or suggestions will be greatly appreciated.

Thanks,
Walter

 

[Erel]

java.util.Map javaMap = map.getObject();

It will warn about missing generic type. Ignore the warning.

 

[walterf25]

java.util.Map javaMap = map.getObject();

It will warn about missing generic type. Ignore the warning.

Thanks Erel.

Walter