Issues and solutions I've taken

[NetkoNefarious]

Foreword: many issues can be fixed by applying certain steps from the Getting Started guide.

1. No Greeter.java (wrapper code)
   Solution:

• Download Solicity compiler (check the .sol file for version, currently 0.4.25 is needed for the file) and web3j cli.
• Follow this guide to generate the Java code you need

2. Cannot resolve 'ethLogFlowable'
   Solution: add into build.gradle

• compile ('org.web3j:core:4.1.0') (Java 8)
• compile ('org.web3j:core:4.1.0-android') (Android)

3. RxJava dependency missing
   Solution: add into build.gradle

• implementation "io.reactivex.rxjava2:rxjava:2.x.y"
  With x and y replaced by the version number found here.

[JoaquimLey]

This seems like a good candidate for a PR :)

[iikirilov]

1. The web3j-gradle-plugin will generate the smart-contract wrapper for you when you build the project

2. and 3. look like separate issues.

[NetkoNefarious]

The web3j-gradle-plugin will generate the smart-contract wrapper for you when you build the project

I didn't know this, I thought you needed the CLI to generate them.

[iikirilov]

@NetkoNefarious the plugin is relatively new.

Regarding 2. and 3. they should not be issues in a fresh clone on master branch. I believe these are issues unique to your environment.

I see you are developing on android. This sample project is not designed to be an android starter application so some changes are required.