Android Question Can not Read JSON Data from Web API

[junaidahmed]

First Time I am trying to read Json Data from Web API.but its through an exception.Please check below log error and advise how to resolve

** Service (httputils2service) Start **
ResponseError. Reason: Method Not Allowed, Response: {"Message":"The requested resource does not support http method 'POST'."}
Error occurred on line: 122 (Main)
org.json.JSONException: End of input at character 0 of
at org.json.JSONTokener.syntaxError(JSONTokener.java:449)
at org.json.JSONTokener.nextValue(JSONTokener.java:97)
at anywheresoftware.b4a.objects.collections.JSONParser.NextArray(JSONParser.java:60)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:710)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:339)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:249)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:139)
at anywheresoftware.b4a.BA.raiseEvent(BA.java:166)
at anywheresoftware.b4a.shell.DebugResumableSub$RemoteResumableSub.resume(DebugResumableSub.java:19)
at anywheresoftware.b4a.BA.checkAndRunWaitForEvent(BA.java:240)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:132)
at anywheresoftware.b4a.BA.raiseEvent(BA.java:166)
at anywheresoftware.b4a.keywords.Common$14.run(Common.java:1736)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6776)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1518)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1408)

Sub Activity_Create(FirstTime As Boolean)
    
    'Do not forget to load the layout file created with the visual designer. For example:
    
    
    Activity.LoadLayout("ProductionEntry")

    If FirstTime = True Then
        intKeyBoardMode = 1
        StrURLPath = "http://103.76.188.138:85/WebAPI/api/ProductionEntry/"
        
        SpinnerMap.Initialize
        
        Dim parser As JSONParser
        Wait For(ExecuteJson("OperationTable","GetOperationTable")) Complete (Result As String)
        parser.Initialize(Result)
        
        Dim root As List = parser.NextArray
        For Each colroot As Map In root
            CboTable.Add(colroot.Get("OperationTableName"))
            SpinnerMap.Put(colroot.Get("OperationTableName"), colroot.Get("OperationTableCode"))
        Next
        
        
        
    End If
    
    
End Sub


Sub ExecuteJson(StrJobName As String,StrAction As String) As ResumableSub
    
    Dim Job As HttpJob
    Dim StrJson As String
    Job.Initialize(StrJobName, Me)
    Job.PostString(StrURLPath & StrAction,"")
    Job.GetRequest.SetHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:27.0) Gecko/20100101 Firefox/27.0")
    Job.GetRequest.SetContentType("application/json;charset=UTF-8")
    Wait For (Job) JobDone(j As HttpJob)
    If j.Success Then
        StrJson = j.GetString   
    End If
    Return StrJson
    
End Sub

 

[DonManfred]

org.json.JSONException: End of input at character 0 of

You are posting a Empty JSON

Job.PostString(StrURLPath & StrAction,"")

Why yre you using POSTSTRING and do not post a valid json structure to this endpoint?
Additionally the error suggests that this endpoint does not allow POST

{"Message":"The requested resource does not support http method 'POST'."}

 

[junaidahmed]

Thanks for quick reply...

Actually I would like to get JSON Data and Loaded it into Combobox.Please check below URL and advise which method I should use instead of "PostString"...

http://103.76.188.138:85/WebAPI/api/ProductionEntry/GetOperationTable

 

[DonManfred]

Post the Documentation of the Webapi. Without knowing it it is hard to give any congrete Answer.

 

[DonManfred]

Please check below URL and advise which method I should use instead of "PostString"...

http://103.76.188.138:85/WebAPI/api/ProductionEntry/GetOperationTable

THIS endpoint you get with using GET (job.Download)

But this endpoint is different from the one in #1!

 

[junaidahmed]

Actually I have used ASP.NET Web API 2. For that I have used Model and controller and also please check above URL for output of JSON

Model:-

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace mPortWebAPI.Models
{
    public class OperationTableModel
    {
        public string OperationTableCode { get; set; }
        public string OperationTableName { get; set; }
      

    }
}

Controller :-

   [HttpGet]
        [ActionName("GetOperationTable")]

        public List<OperationTableModel> GetOperationTable()
        {
            using (DbManager Db = new DbManager())
            {
                return Db.SetCommand("Select OperationTableCode,OperationTableName from GloveERP.Dbo.Common_Ref_OperationsTable ").ExecuteList<OperationTableModel>();
                Db.Close();
                Db.Dispose();
            }
        }

WebAPI Config :-

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Web.Http;
using Microsoft.Owin.Security.OAuth;
using Newtonsoft.Json.Serialization;

namespace mPortWebAPI
{
    public static class WebApiConfig
    {
        public static void Register(HttpConfiguration config)
        {
          
            config.Routes.MapHttpRoute(
            name: "API Default",
            routeTemplate: "api/{controller}/{action}/{id}",
            defaults: new { id = RouteParameter.Optional });
                      
        }
    }
}

 

[DonManfred]

Post the DOCUMENTATION.
Without it i CAN´T help. I don´t know what you have coded in ASP.NET and i am not interested in ASP.NET code. I do not know ASP.NET.

I can´t help here, sorry.

 

[junaidahmed]

https://docs.microsoft.com/en-us/as...th-aspnet-web-api/tutorial-your-first-web-api

 

[junaidahmed]

Please help...

Actually I am using this web API in other Mobile apps (DevExtreme Framework) ...

I don't understand which kind of Documentation you required....

 

[Erel]

It should be Job.Download not Job.PostString. Download = GET request.

 

[junaidahmed]

Still I have not solved my problem... I have removed "Job.PostString" and added Job.Download.Please check below log and advise the same.....

Sub ExecuteJson(StrJobName As String,StrAction As String) As ResumableSub
  
   Dim Job As HttpJob
   Dim StrJson As String
   Job.Initialize(StrJobName, Me)
   Job.Download("http://103.76.188.138:85/WebAPI/api/ProductionEntry/GetOperationTable")
   Job.GetRequest.SetHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:27.0) Gecko/20100101 Firefox/27.0")
   Job.GetRequest.SetContentType("application/json;charset=UTF-8")
   Wait For (Job) JobDone(j As HttpJob)
   If j.Success Then
       StrJson = j.GetString   
   End If
   Return StrJson
  
End Sub

Log Error :-

at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1518)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1408)
** Activity (main) Resume **
--------- beginning of system
** Activity (main) Create, isFirst = true **
Error occurred on line: 143 (Main)
java.lang.RuntimeException: Request does not support this method.
at anywheresoftware.b4h.okhttp.OkHttpClientWrapper$OkHttpRequest.SetContentType(OkHttpClientWrapper.java:493)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.shell.Shell.runVoidMethod(Shell.java:755)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:345)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:249)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:139)
at camera.scanner.main.afterFirstLayout(main.java:104)
at camera.scanner.main.access$000(main.java:17)
at camera.scanner.main$WaitForLayout.run(main.java:82)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6776)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1518)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1408)
** Activity (main) Resume **

 

[Erel]

Content Type header should only be set when you send POST or PUT requests.

 

[junaidahmed]

Thanks Erel........

That's great support.........

Now Its working fine..............