Adding library to Business Logic project

[vikzilla]

I am trying to use a 3rd-Party library with my Business Logic code; it is this one here: okhttp

Normally with an Android Studio project I just add it to the gradle. But I’m unsure how to integrate it here with the project / code generated by Backendless.

Thank you

[mark-piller]

See step 2 under “Customizing and Running Code”

https://backendless.com/documentation/business-logic/java/bl_getting_started.htm

[vikzilla]

I’ve added the JAR to my libs folder, however when I try to deploy my code I get an error:

http://support.backendless.com/public/attachments/6ef92d6837cd2f1e8284514a4d540034.png</img>

[mark-piller]

This error means that either the specified class or one of its dependencies is missing.

[vikzilla]

I added the JAR for the library to the libs folder as suggested. It appears to all be there:

http://support.backendless.com/public/attachments/a2ee8cad02cef67a0a4654c56f86624e.png</img>
Is there something extra I need to be doing for this to work when deploying to the server as I am attempting to do?

[vikzilla]

I am thinking maybe I did not add the library correctly, because when I ran the code locally I got a similar error:

http://support.backendless.com/public/attachments/ccdc2a847be4db36bfadfd1daee507c8.png</img>

[vikzilla]

Here’s the code I am trying to deploy:

@Override
public void execute( String appVersionId ) throws Exception
{
  String apiKey = "6e46fb2e1acef97d5bb8b75d4e5c9e5a";
  String forecastUrl = "https://api.forecast.io/forecast/" + apiKey + "/" + "41.9484" + "," + "-87.6553";


  OkHttpClient client = new OkHttpClient();


  Request request = new Request.Builder()
          .url(forecastUrl)
          .build();
  Call call = client.newCall(request);


  call.enqueue(new Callback() {
    @Override
    public void onFailure(Call call, IOException e) {


    }


    @Override
    public void onResponse(Call call, Response response) throws IOException {


    }
  });
}

I am able to deploy it when I comment out any references to the Callback class. Which I find odd because why can I deploy when referencing other classes from the same library?

[vikzilla]

Ah, I am guessing this could be related to trying to run asynchronous code on the server side.

[vikzilla]

Unfortunately I got this error back when I tried running synchronously:

Caused by: java.lang.NoClassDefFoundError: okhttp3/OkHttpClient

So still wondering if I am importing the library incorrectly.

[mark-piller]

Check the "location.jar" property in in bin/runner.properties. It must point to your libs folder. Make sure that all other JAR dependent files that the jar you put in there are also available in the libs folder.

[vikzilla]

1. Yes, it properly points to my libs folder

2. I believe they are all available in the libs folder, as this is the only JAR I added:

http://support.backendless.com/public/attachments/22da1a3a19a0f8d097d6d69399b04874.png</img>

[vikzilla]

Here’s a more detailed look at the error I get back from the server when the code runs / is locally debugged through code runner:

http://support.backendless.com/public/attachments/abb0e79fbe06059471a1ce00903dcfd8.png</img>

[mark-piller]

A dependency is missing. Do you research and find out what other JARs okhttp depends on.

[vikzilla]

I noticed it says my JAVA_HOME and JRE_HOME are not set:

http://support.backendless.com/public/attachments/c7231f7f2b88641bf7bdb2c02823268d.png</img>

Wondering if this could be related and how to fix it, thanks

[mark-piller]

It has nothing to do with the problem you’re experiencing. There is a missing dependency…

[vikzilla]

I seem to have resolved the JAR issue, but it now claims my code is using thread manipulation:

http://support.backendless.com/public/attachments/a3dda380e669b7a5173b1147584391e9.png</img>

However, the line it’s referencing does not open a new thread; it is synchronous (as recommended here):

Response response = client.newCall(request).execute();

I am unsure why the server is telling me I am attempting thread manipulation if I am using a synchronous method.

[mark-piller]

Look at the stack trace. The new thread is created in okhttp3.ConnectionPool.put (line 134)

[m-van-dillen]

For future reference: You’ll also need Okio, which OkHttp uses for fast I/O and resizable buffers.