B4J Question Error in Jserver and POST method

Marcos Alves · Apr 18, 2019

Hello all,

I'm trying to receive data in a B4J server using a POST method. To do this I created a local form like this:

B4X:

html>
<html>
<body>
<form action="http://127.0.0.1:51042/pushserver" method="post" id="usrform">
idUser: <input type="text" name="username"><br>
Token: <input type="text" name="token"><br>
sessionId: <input type="text" name="sessionid"><br>
<input type="submit">
</form>
<textarea name="data" form="usrform"></textarea>
</body>
</html>
</html>

Open this form in Chrome and, running the java server, it receives the POST call in this code:

B4X:

req As ServletRequest
Dim postMap As Map
postMap.Initialize
postMap = req.GetMultipartData(File.DirApp,1000000000)
Log( "sessionid -> " & req.GetParameter("sessionid") )

The POST event is arriving, the req.ContentType is correct (application/x-www-form-urlencoded), the req.method is POST but I can't recover the POST fields or values, doesn't matter what method I use (postMap is empty and GetParameter - that I know that should be used for GET method, but tested...) .
What am I doing wrong?

Erel · Apr 19, 2019

Marcos Alves said:
What am I doing wrong?

Never initialize a variable before you assign a different object to the same variable.

B4X:

Dim postMap As Map = req.GetMultipartData(...)

The form fields are added to the map: https://www.b4x.com/android/forum/threads/postmultipart-handle-on-b4j-server.103487/#post-648633

Marcos Alves · Apr 19, 2019

Erel said:
Never initialize a variable before you assign a different object to the same variable.

B4X:

Dim postMap As Map = req.GetMultipartData(...)

The form fields are added to the map: https://www.b4x.com/android/forum/threads/postmultipart-handle-on-b4j-server.103487/#post-648633

ok @Erel ,

I just tested with the code:

B4X:

            Dim postMap As Map   
            Dim FullUri As String = req.FullRequestURI       
            postMap = req.GetMultipartData(File.DirApp,10000000000000)

And Post call:

B4X:

<html>
<html>
<body>
<form action="http://127.0.0.1:51042/pushserver" method="post" id="usrform">
idUser: <input type="text" name="username"><br>
Token: <input type="text" name="token"><br>
sessionId: <input type="text" name="sessionid"><br>
<input type="submit">
</form>
<textarea name="data" form="usrform"></textarea>
</body>
</html>
</html>

But still getting a zero size Map...

An interesting thing is changing to GET and recovering the parameters with req.GetParameter is working...

How can I debug this to find out the problem? Really don't know. I already opened the req object and its big! I couldn't find the parameters MAP inside this even to at least check if they are in the object after receiving the POST... what can I do to debug?

Erel · Apr 20, 2019

There is a confusion here with two protocols: application/x-www-form-urlencoded and multipart/form-data.

Set the form encoding to multipart:

B4X:

<form action="http://127.0.0.1:51042/pushserver" method="post" id="usrform" enctype="multipart/form-data">

Marcos Alves · Apr 20, 2019

Erel said:
There is a confusion here with two protocols: application/x-www-form-urlencoded and multipart/form-data.

Set the form encoding to multipart:

B4X:

<form action="http://127.0.0.1:51042/pushserver" method="post" id="usrform" enctype="multipart/form-data">

Thanks @Erel . My mistake, it was a simple solution! I didn't notice that because when using the multipartpost methods called FROM B4X app, the server written in php recognizes application/x-www-form-urlencode AND multipart/form-data with the same code (I actually use forms to test the codes those will be called by htpmultipart requests by apps)...

I'll fix the form code! Thanks master!

B4J Question Error in Jserver and POST method

Marcos Alves

Well-Known Member

Erel

B4X founder

Marcos Alves

Well-Known Member

Erel

B4X founder

Marcos Alves

Well-Known Member

Similar Threads