IWF-980: [Java SDK] Add instructions for local library testing (#302)

Author: samuel27m

README.md

@@ -67,6 +67,26 @@ See more in https://github.com/indeedeng/iwf#what-is-iwf
 
 Run the command `git submodule update --remote --merge` to update IDL to the latest commit
 
+### Local testing
+
+If you'd like to test your changes to the SDK with the workflows in the [samples](https://github.com/indeedeng/iwf-java-samples) repo, 
+use the local publishing command:
+
+1. Run:
+  ```
+  ./gradlew publishToMavenLocal -x signMavenJavaPublication
+  ```
+
+2. In the [samples](https://github.com/indeedeng/iwf-java-samples) repo, make sure your `build.gradle` depends on the same version you just published. To find which version you published, open the SDK's `build.gradle` file and look for the `version = "x.y.z"` line near the bottom of the file. Then run:
+  ```
+   ./gradlew --refresh-dependencies build
+  ```
+
+3. Once you're done, to remove the locally published version, run:
+  ```
+  ./gradlew unpublishFromMavenLocal
+  ```
+
 ### Repo structure
 * `.github/workflows/`: the GithubActions workflows
 * `iwf-idl/`: the idl submodule

build.gradle

@@ -122,6 +122,18 @@ compileJava.dependsOn tasks.openApiGenerate
 
 sourceSets.main.java.srcDirs += "$buildDir/generated/src/main/java"
 
+// Custom task to unpublish from local Maven repository
+// Usage: ./gradlew unpublishFromMavenLocal
+task unpublishFromMavenLocal(type: Delete) {
+    def groupPath = "io/iworkflow/iwf-java-sdk"
+    def version = project.version
+    def m2Repo = "${System.getProperty('user.home')}/.m2/repository"
+    delete "$m2Repo/$groupPath/$version"
+    doFirst {
+        println "Deleting $m2Repo/$groupPath/$version"
+    }
+}
+
 publishing {
     publications {
         mavenJava(MavenPublication) {
@@ -173,4 +185,4 @@ nexusPublishing {
             // password = project.property('myNexusPassword')
         }
     }
-}
+}