Improve contributing guide (#645)

Author: longquanzheng

CONTRIBUTING.md

@@ -7,10 +7,23 @@ This doc is intended for contributors to `cadence-java-client` (hopefully that's
 ## Development Environment
 
 * Java 11 (currently, we use Java 11 to compile Java 8 code).
-* Thrift 0.9.3
-* Gradle build tool
+* Thrift 0.9.3 (use [homebrew](https://formulae.brew.sh/formula/[email protected]) or [distribution](https://downloads.apache.org/thrift/0.9.3/))
+* Gradle build tool [6.x](https://github.com/uber/cadence-java-client/blob/master/gradle/wrapper/gradle-wrapper.properties)
 * Docker
 
+:warning: Note 1: You must install the 0.9.x version of Thrift. Otherwise compiling would fail at error `error: package org.apache.thrift.annotation does not exist`
+
+:warning: Note 2: It's currently compatible with Java 8 compiler but no guarantee in the future. 
+
+## IntelliJ IDE integration (Optional)
+
+* Make sure you set the gradle path with the right version ([currently 6.x](https://github.com/uber/cadence-java-client/blob/master/gradle/wrapper/gradle-wrapper.properties))
+
+![IntelliJ](https://user-images.githubusercontent.com/4523955/135696878-81c1e62e-eb04-45e6-9bcb-785ac38b6607.png)
+
+* Then all the below `gradlew` command can be replaced with the Gradle plugin operation 
+![Gradle](https://user-images.githubusercontent.com/4523955/135696922-d43bc36d-18a4-4b7b-adee-0fe8300bf855.png)
+
 ## Licence headers
 
 This project is Open Source Software, and requires a header at the beginning of
@@ -32,16 +45,42 @@ Overcommit adds some requirements to your commit messages. At Uber, we follow th
 [Chris Beams](http://chris.beams.io/posts/git-commit/) guide to writing git
 commit messages. Read it, follow it, learn it, love it.
 
-## Test
 
-Testing and building cadence-java-client requires running cadence docker locally, execute:
+##  Build & Publish & Test locally
+Build with:
+
+```bash
+./gradlew build
+```
+
+To test locally, you can publish to [MavenLocal](https://docs.gradle.org/current/userguide/declaring_repositories.html#sec:case-for-maven-local)
+
+1. Change `build.gradle`:
+Comment out the first section in `publications` ( line 160 to line 191 in [this commit](https://github.com/uber/cadence-java-client/blob/c9ec6786aa9f866b0310292ea3ee5df63adc8799/build.gradle#L160))
 
+2. Change the [version](https://github.com/uber/cadence-java-client/blob/c9ec6786aa9f866b0310292ea3ee5df63adc8799/build.gradle#L43) to add a `local` suffix. E.g.
+```
+version = '3.3.0'
+```` 
+to 
+```
+version = '3.3.0-local'
+``` 
+Then run the command
 ```bash
-curl -O https://raw.githubusercontent.com/uber/cadence/master/docker/docker-compose.yml
-docker-compose up
+./gradlew publishToMavenLocal
 ```
+Now you have the local cadence-java-client in your machine using veriosn `3.3.0-local`
 
-(If this does not work, see instructions for running the Cadence Server at https://github.com/uber/cadence/blob/master/README.md.)
+3. To test with Cadence Java Samples, [change](https://github.com/uber/cadence-java-samples/blob/master/build.gradle#L32) `mavenCentral()` to `mavenLocal()`
+and also change the [version](https://github.com/uber/cadence-java-samples/blob/a79d8d6e5860cf9986bf549fc1f96badecb09f8f/build.gradle#L38) with your suffix. 
+
+Then `./gradlew build` and refer to the sample repo for how to run the code(it needs to run with a [Cadence server](https://github.com/uber/cadence)). 
+
+:warning: If you run into problem with `version.properties` [creation task](https://github.com/uber/cadence-java-client/blob/c9ec6786aa9f866b0310292ea3ee5df63adc8799/build.gradle#L109), you can comment the task out. It's okay for local testing.  
+The property file is being used by [Version class](https://github.com/uber/cadence-java-client/blob/master/src/main/java/com/uber/cadence/internal/Version.java#L39)to report the library version for logging/metrics. 
+
+## Unit & Integration Test
 
 Then run all the tests with:
 
@@ -60,26 +99,3 @@ STICKY_OFF=true USE_DOCKER_SERVICE=true ./gradlew test
 
 Also, if there is any Buildkite test failure that you cannot reproduce locally, 
 follow [buildkite docker-compose](./docker/buildkite/README.md) instructions to run the tests.
-
-##  Build & Publish
-Build with:
-
-```bash
-./gradlew build
-```
-
-To test locally, change `build.gradle`:
-1. Comment out the whole `publications`  
-2. Change 
-```
-group = 'com.uber.cadence'
-```` 
-to 
-```
-group = 'com.local.cadence'
-``` 
-Then run the command
-```bash
-./gradlew publishToMavenLocal
-```
-Now you can use the local cadence-java-client in your laptop.