Android Question Sending JSON data to B4J server.

[Eme Fibonacci]

After researching on forum I made a code work.

However, I would like something better. More "professional". More safe.

Do you have an example that sends JSON code and gets in BJ4?

Thank you.

 

[DonManfred]

B4J? Shouldn´t the thread created in the B4J Forum then?

Posting the json is the same in B4A/B4J... There are a lot of examples in the forum. Just search for them.
What you need is to know how to get it in B4J.

 

[Eme Fibonacci]

B4J? Shouldn´t the thread created in the B4J Forum then?

Posting the json is the same in B4A/B4J... There are a lot of examples in the forum. Just search for them.
What you need is to know how to get it in B4J.

Sending from B4A.

 

[OliverA]

After researching on forum I made a code work.

What code and what did you get to work? Are you already sending/receiving JSON or would you like to send/receive JSON? If you're staying in the B4x environment, then why not serialize? Not everything has to be JSON.

 

[johndb]

After researching on forum I made a code work.

However, I would like something better. More "professional". More safe.

Do you have an example that sends JSON code and gets in BJ4?

Thank you.

If you are using a closed environment i.e Your own B4J server then I agree with @OliverA. In my B4A Client - B4J Server environment I use encrypted serialization of data (maps, lists, ...) using the RandomAccessFile library.

 

[Eme Fibonacci]

What code and what did you get to work? Are you already sending/receiving JSON or would you like to send/receive JSON? If you're staying in the B4x environment, then why not serialize? Not everything has to be JSON.

I can't put an image in serialized object. Right?

 

[OliverA]

You convert the image to a byte array, send it, then convert byte array back to an image. How to do it? Look at the example's @Erel gives for B4XSerializator (source for B4A, B4J and B4i are given). Link: https://www.b4x.com/android/forum/threads/b4x-network-asyncstreams-b4xserializator.72149/.

 

[Eme Fibonacci]

You convert the image to a byte array, send it, then convert byte array back to an image. How to do it? Look at the example's @Erel gives for B4XSerializator (source for B4A, B4J and B4i are given). Link: https://www.b4x.com/android/forum/threads/b4x-network-asyncstreams-b4xserializator.72149/.

Very interesting. Can you show advantages and disadvantages?

 

[LucaMs]

I can't put an image in serialized object. Right?

Does this have to do with the initial question?
JSON is just text; you should convert the image to a string (base64)

 

[KMatle]

JSON is just text; you should convert the image to a string (base64)

Yep. That's the way I do it. I use a list with maps (can contain f.e. rows you want to insert). Convert that to a string. With that you can additionally use encryption if you need it. If you need to add binary data (like an imag) convert it to Base64 as Lucas posted.

JsonList.Initialize
    JsonZeileMap.Initialize
    JsonZeileMap.put("Action", "Insert")
    JsonZeileMap.put("uname", "xxxx")
    JsonZeileMap.put("upw", SHA256Hash("pw"))
    JsonZeileMap.put("umail", "kk@kk.de")
    JsonZeileMap.put("myimage", SomeBase64String)
     
    JsonList.add(JsonZeileMap)
 
    Dim JSONGenerator As JSONGenerator
    JSONGenerator.Initialize2(JsonList)
 
    Dim JSONstring As String
    JSONstring = JSONGenerator.ToString
    Log(JSONstring)

    Dim LoginJob As HttpJob
    LoginJob.Initialize("InsertNew", Me)
    LoginJob.PostString(Servername & "/login/loginpre.php", JSONstring)

Benefits:

This solution (JSON, Base64, lists, maps) is compatible with B4x AND all other platforms (.net, PHP, etc.) as it is just a string and a list with maps is just an array containing arrays.

PHP:

$json = file_get_contents("php://input");

    $jsall = array();
    $jsone = array();

    $jsall=json_decode($json, true); //get the LIST

    $jsone=$jsall[0]; //first MAP of the LIST

    //get contents of the map (looks like map.get("umail")
    $umail=mysqli_real_escape_string($con,$jsone["umail"]);
    $upw=mysqli_real_escape_string($con,$jsone["upw"]);
    $uname=mysqli_real_escape_string($con,$jsone["uname"]);

This is a simple example. In my apps I use encryption (AES to be compatible with other platforms). As "JSONSTRING" is a simple string, you can encrypt it very easy.