Okhttp3 jar missing okio?

I am trying to make a simple Java program to upload a bunch of images I have to imgur. But I am running into problem after problem and cannot just get okhttp to work. At this point the time I have spent trying to solve this has been way longer than it will take for me to write the program itself. I am very new to this kind of stuff so be patient with me please.

So, right now I have the following code from this tutorial:

RequestBody requestBody = new MultipartBody.Builder()
                .addFormDataPart("new", "This is my new TODO")
                .addFormDataPart("image", "attachment.png",
                        RequestBody.create(new File(""), MediaType.parse("image/png"))
                )
                .setType(MultipartBody.FORM)
                .build();

Which is giving an error on the RequestBody.create() part:

The type okio.ByteString cannot be resolved. It is indirectly referenced from required .class files

When Googling this error, I find this page which says I'm missing the okio library. I thought this would be included with the okhttp jar. I download the okio jar anyway and add it to my project, but the error doesn't change. I have no idea what else might be wrong.

Ok, I figured out your problem.

Okio source code from 3.0.0-Alpha-10 and above has been re-written with Kotlin.

Use this version https://repo1.maven.org/maven2/com/squareup/okio/okio/3.0.0-alpha.9/ This one is written in Java, before the migration to Kotlin.

The code below will compile:

package example;

import java.io.File;
import okhttp3.MediaType;
import okhttp3.MultipartBody;
import okhttp3.RequestBody;


public class OkHttpExample {

    public void example() {
        
        RequestBody requestBody = new MultipartBody.Builder()
                .addFormDataPart("new", "This is my new TODO")
                .addFormDataPart("image", "attachment.png",
                        RequestBody.create(new File(""), MediaType.parse("image/png"))
                )
                .setType(MultipartBody.FORM)
                .build();
    }
    
}

See build path dependencies:

Once in your build path, in eclipse you can open the jar file, and see the contents: ByteString.class is included: