B4J Question Consuming streaming data from HTTP call

Sub Process_Globals

    Private MainForm As Form
    Private btnConnect As Button   
    Private AStreams As AsyncStreamsText
    Public j As HttpJob ' Using jOkHttpUtils2 library

End Sub

Sub AppStart (Form1 As Form, Args() As String)
    MainForm = Form1
    MainForm.RootPane.LoadLayout("Form1")
    MainForm.Show
    
    j.Initialize("json", Me)

End Sub

Sub btnConnect_MouseClicked (EventData As MouseEvent)

    j.Download("https:// . . . . . /read/ID?ak=API_Key")
            
    Log("Response: " & j.Response)
    Log("Error: " & j.ErrorMessage)
    Log("Success: " & j.Success)

    If j.Success then AStreams.Initialize(Me, "AStreams", j.GetInputStream, Null)

End Sub

Sub Process_Globals
 
    Private MainForm As Form
    Private btnConnect As Button
 
    Private stream As AsyncStreamsText
    Private currentjob As HttpJob
 
End Sub

Sub AppStart (Form1 As Form, Args() As String)
    MainForm = Form1
    MainForm.RootPane.LoadLayout("Form1")
    MainForm.Show
End Sub

Sub btnConnect_MouseClicked (EventData As MouseEvent)

    Dim j As HttpJob '<=== Use new instance for each request
    j.Initialize("json", Me)
    j.Download("https:// . . . . . /read/ID?ak=API_Key")
    Wait For (j) JobDone (j As HttpJob) '<=== Wait for download complete
 
    Log("Response: " & j.Response)
    Log("Error: " & j.ErrorMessage)
    Log("Success: " & j.Success)

    If j.Success Then
        stream.Initialize(Me, "AStreams", j.GetInputStream, Null)
        currentjob = j
    Else
        j.Release
    End If
 
End Sub

<?php
$url = "https:// . . . . . /read/ID?ak=API_Key";
$r   = new ReaderExample();
$r->run($url, 'processdata');


// Callback function to process the data
function processdata($data)
{
    // Do whatever you need to do with the data
    var_dump($data);
}


class ReaderExample
{
    protected $msg_buffer = '';
    protected $callback = '';
    
    const MAX_LENGTH = 1000000;
    const EOL_SEPARATOR = "\r\n";
    
    public function run($url, $callbackfunction)
    {
        $this->callback = $callbackfunction;
        $curlURL        = $url;
        $ch             = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_WRITEFUNCTION, array(
            $this,
            'on_Read'
        ));
        curl_exec($ch);
        curl_close($ch);
        return 1;
    }
    
    protected function on_Read($ch, $str)
    {
        $this->msg_buffer .= $str;
        while (($p = strrpos($this->msg_buffer, self::EOL_SEPARATOR)) !== false) {
            $msgs             = explode(self::EOL_SEPARATOR, substr($this->msg_buffer, 0, $p));
            $this->msg_buffer = substr($this->msg_buffer, $p + strlen(self::EOL_SEPARATOR));
            foreach ($msgs as $msg)
                $this->on_Read_Message(rtrim($msg, self::EOL_SEPARATOR) . self::EOL_SEPARATOR);
        }
        
        if (strlen($this->msg_buffer) > self::MAX_LENGTH) {
            $this->on_Read_Message($this->msg_buffer);
            $this->msg_buffer = "";
        }
        return strlen($str);
    }
    
    public function on_Read_Message($msgIn)
    {
        $msg = json_decode($msgIn, true);
        if (!$msg) {
            error_log("INVALID MESSAGE $msgIn");
            return false;
        }
        call_user_func($this->callback, $msg);
        return true;
    }
    
}
?>

Sub Process_Globals
    Private MainForm As Form   
    Private btnConnect As Button
    Private wv1 As WebView
    Private startPage As String = "https:// . . . . . /read/ID?ak=API_Key"
    Private we,Temp As JavaObject
End Sub

Sub AppStart (Form1 As Form, Args() As String)
    MainForm = Form1
    MainForm.RootPane.LoadLayout("Form1")
    MainForm.Show
    we.InitializeNewInstance("javafx.scene.web.WebEngine",Null)
    Temp = wv1
    we = Temp.RunMethod("getEngine",Null)
End Sub

Sub btnConnect_MouseClicked (EventData As MouseEvent)   
    we.RunMethod("load",Array As Object(startPage))   
End Sub

Sub wv1_PageFinished (Url As String)
    Log("Page finished: " & Url)
End Sub

Sub Class_Globals
    Private mTarget As Object
    Private mEventName As String
    Private hc As OkHttpClient
    Private const PackageName As String = "b4j.example" '<------ change as needed
    Public charset As String = "UTF8"
    Private sb As StringBuilder
End Sub

Public Sub Initialize (TargetModule As Object, EventName As String)
    mTarget = TargetModule
    mEventName = EventName
    hc.Initialize("hc")
    sb.Initialize
End Sub

Public Sub Connect(url As String)
    Dim req As OkHttpRequest
    req.InitializeGet(url)
    hc.Execute(req, 0)
End Sub

Private Sub hc_ResponseError (Response As OkHttpResponse, Reason As String, StatusCode As Int, TaskId As Int)
    Log("Error: " & StatusCode)
End Sub

Private Sub hc_ResponseSuccess (Response As OkHttpResponse, TaskId As Int)
    CallSubDelayed2(mTarget, mEventName & "_Connected", True)
    Dim out As JavaObject
    out.InitializeNewInstance($"${PackageName}.fls$MyOutputStream"$, Array(Me))
    Response.GetAsynchronously("req", out, False, 0)
    Wait For req_StreamFinish (Success As Boolean, TaskId As Int)
    Log("Stream finish")
End Sub

Private Sub Data_Available (Buffer() As Byte)
    Dim newDataStart As Int = sb.Length
    sb.Append(BytesToString(Buffer, 0, Buffer.Length, charset))
    Dim s As String = sb.ToString
    Dim start As Int = 0
    For i = newDataStart To s.Length - 1
        Dim c As Char = s.CharAt(i)
        If i = 0 And c = Chr(10) Then '\n...
            start = 1 'might be a broken end of line character
            Continue
        End If
        If c = Chr(10) Then '\n
            CallSubDelayed2(mTarget, mEventName & "_NewText", s.SubString2(start, i))
            start = i + 1
        Else If c = Chr(13) Then '\r
            CallSubDelayed2(mTarget, mEventName & "_NewText", s.SubString2(start, i))
            If i < s.Length - 1 And s.CharAt(i + 1) = Chr(10) Then '\r\n
                i = i + 1
            End If
            start = i + 1
        End If
    Next
    If start > 0 Then sb.Remove(0, start)
End Sub

#if Java
import java.io.*;
public static class MyOutputStream extends OutputStream {
    B4AClass cls;
    public MyOutputStream (B4AClass cls) {
        this.cls = cls;
    }
    
    public void write(int b) throws IOException {
        cls.getBA().raiseEventFromDifferentThread (null, null, 0, "data_available", true, new Object[] {new byte[] {(byte)b}});
    }
    public void write(byte b[], int off, int len) throws IOException {
        byte[] bb = new byte[len];
        System.arraycopy(b, off, bb, 0, len);
        cls.getBA().raiseEventFromDifferentThread (null, null, 0, "data_available", true, new Object[] {bb});
    }
}
#End If

Sub Process_Globals
    Private MainForm As Form
    Private btnConnect As Button
    Private f As fls
End Sub

Sub AppStart (Form1 As Form, Args() As String)
        MainForm = Form1
    MainForm.RootPane.LoadLayout("Form1") 'Load the layout file.
    MainForm.Show   
    f.Initialize(Me, "fls1")
End Sub

Sub btnConnect_MouseClicked (EventData As MouseEvent)
    f.Connect("https:// . . . . . /read/ID?ak=API_Key")
End Sub

Sub fls1_Connected(State As Boolean)
    btnConnect.Text = "Connected"
End Sub

Sub fls1_NewText(Text As String)
    Dim parser As JSONParser
    parser.Initialize(Text)
    Dim root As Map = parser.NextObject

'    Remainder of data processing

End Sub