[WIP] Workflow hello world example

.github/workflows/pre-release.yml

@@ -57,7 +57,7 @@ jobs:
       # When adding a new example make sure it's listed here
       - name: Find and replace restateVersion in build.gradle.kts for java examples
         if: github.event.inputs.sdkJavaVersion != ''
-        run: for jvmDir in hello-world-http hello-world-lambda food-ordering/app tour-of-restate patterns; do sed -i 's/val restateVersion = "[0-9A-Z.-]*"/val restateVersion = "${{ inputs.sdkJavaVersion }}"/' java/$jvmDir/build.gradle.kts; done
+        run: for jvmDir in hello-world-http hello-world-lambda hello-world-workflow food-ordering/app tour-of-restate patterns; do sed -i 's/val restateVersion = "[0-9A-Z.-]*"/val restateVersion = "${{ inputs.sdkJavaVersion }}"/' java/$jvmDir/build.gradle.kts; done
       - name: Find and replace restateVersion in build.gradle.kts for kotlin templates
         if: github.event.inputs.sdkJavaVersion != ''
         run: for jvmDir in hello-world-http hello-world-lambda; do sed -i 's/val restateVersion = "[0-9A-Z.-]*"/val restateVersion = "${{ inputs.sdkJavaVersion }}"/' kotlin/$jvmDir/build.gradle.kts; done
@@ -81,6 +81,12 @@ jobs:
         with:
           arguments: check
           build-root-directory: java/hello-world-lambda
+      - name: Test java/hello-world-workflow
+        if: github.event.inputs.sdkJavaVersion != ''
+        uses: gradle/gradle-build-action@v2
+        with:
+          arguments: check
+          build-root-directory: java/hello-world-workflow
       - name: Test java/food-ordering
         if: github.event.inputs.sdkJavaVersion != ''
         uses: gradle/gradle-build-action@v2

.github/workflows/release.yml

@@ -36,6 +36,7 @@ jobs:
             typescript-tour-of-restate.zip
             java-hello-world-http.zip
             java-hello-world-lambda.zip
+            java-hello-world-worfklow.zip
             java-food-ordering.zip
             java-tour-of-restate.zip
             kotlin-hello-world-http.zip

.github/workflows/test.yml

@@ -35,6 +35,11 @@ jobs:
         with:
           arguments: check
           build-root-directory: java/hello-world-lambda
+      - name: Test java/hello-world-workflow
+        uses: gradle/gradle-build-action@v2
+        with:
+          arguments: check
+          build-root-directory: java/hello-world-workflow
       - name: Test java/food-ordering
         uses: gradle/gradle-build-action@v2
         with:

README.md

@@ -13,6 +13,7 @@ Browse this repository to see how easy distributed applications development beco
 | TypeScript | [Hello world on AWS Lambda + CDK](typescript/hello-world-lambda-cdk) |
 | Java       | [Hello World HTTP](java/hello-world-http)                            |
 | Java       | [Hello world on AWS Lambda](java/hello-world-lambda)                 |
+| Java       | [Hello World Workflow](java/hello-world-workflow)                    |
 | Kotlin     | [Hello World HTTP](kotlin/hello-world-http)                          |
 | Kotlin     | [Hello world on AWS Lambda](kotlin/hello-world-lambda)               |
 | Kotlin     | [Hello world on AWS Lambda + CDK](kotlin/hello-world-lambda-cdk)     |

java/README.md

@@ -3,10 +3,11 @@
 This directory contains Restate examples using the Java SDK.
 
 ## Starters
-| Language  | Name / Link                                                     |
-|-----------|-----------------------------------------------------------------|
-| Java      | [Hello World HTTP](hello-world-http)                       |
-| Java      | [Hello world on AWS Lambda](hello-world-lambda)             |
+| Language  | Name / Link                                     |
+|-----------|-------------------------------------------------|
+| Java      | [Hello World HTTP](hello-world-http)            |
+| Java      | [Hello world on AWS Lambda](hello-world-lambda) |
+| Java      | [Hello World Workflow](hello-world-workflow)    |
 
 ## Tutorials
 | Language | Name / Link                                                                  |

java/hello-world-http/src/main/java/dev/restate/sdk/examples/Greeter.java

@@ -9,7 +9,7 @@
  * https://github.com/restatedev/examples/
  */
 
- package dev.restate.sdk.examples;
+package dev.restate.sdk.examples;
 
 import dev.restate.sdk.RestateContext;
 import dev.restate.sdk.common.CoreSerdes;

java/hello-world-workflow/.gitignore

@@ -0,0 +1,35 @@
+# Compiled class file
+*.class
+
+# Log file
+*.log
+
+# BlueJ files
+*.ctxt
+
+# Mobile Tools for Java (J2ME)
+.mtj.tmp/
+
+# Package Files #
+*.jar
+*.war
+*.nar
+*.ear
+*.zip
+*.tar.gz
+*.rar
+
+# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+hs_err_pid*
+
+# Ignore Gradle project-specific cache directory
+.gradle
+
+# Ignore Gradle build output directory
+build
+
+.idea
+*.iml
+
+# Unignore the gradle wrapper
+!gradle/wrapper/gradle-wrapper.jar

java/hello-world-workflow/README.md

@@ -0,0 +1,46 @@
+# Hello world - Java Workflow example
+
+Sample project configuration of a Restate worfklow using the Java interface and HTTP server. It contains:
+
+* [`build.gradle.kts`](build.gradle.kts)
+* [Workflow implementation `LoanApproval`](src/main/java/my/restate/examples/LoanApproval.java)
+* [Test `LoanApprovalTest`](src/test/java/my/restate/examples/LoanApprovalTest.java)
+* [Logging configuration](src/main/resources/log4j2.properties)
+
+## Download the example
+
+- Via the CLI:
+    ```shell
+    restate example java-hello-world-workflow && cd java-hello-world-workflow
+    ```
+
+- Via git clone:
+    ```shell
+    git clone [email protected]:restatedev/examples.git
+    cd examples/java/hello-world-workflow
+    ```
+
+- Via `wget`:
+    ```shell
+    wget https://github.com/restatedev/examples/releases/latest/download/java-hello-world-workflow.zip && unzip java-hello-world-workflow.zip -d java-hello-world-workflow && rm java-hello-world-workflow.zip
+    ```
+
+## Running the example
+
+You can run the example via:
+
+```shell
+./gradlew run
+```
+
+Or from your IDE.
+
+## Running the tests
+
+You can run the tests either via:
+
+```shell
+./gradlew check
+```
+
+Or from your IDE.

java/hello-world-workflow/build.gradle.kts

@@ -0,0 +1,42 @@
+import com.google.protobuf.gradle.id
+
+plugins {
+  java
+  application
+
+  id("com.google.protobuf") version "0.9.1"
+}
+
+repositories {
+  mavenCentral()
+  maven("https://s01.oss.sonatype.org/content/repositories/snapshots/")
+}
+
+val restateVersion = "0.8.0-SNAPSHOT"
+
+dependencies {
+  // Restate SDK
+  annotationProcessor("dev.restate:sdk-api-gen:$restateVersion")
+  implementation("dev.restate:sdk-api:$restateVersion")
+  implementation("dev.restate:sdk-workflow-api:$restateVersion")
+  implementation("dev.restate:sdk-http-vertx:$restateVersion")
+  // To use Jackson to read/write state entries (optional)
+  implementation("dev.restate:sdk-serde-jackson:$restateVersion")
+
+  // Logging (optional)
+  implementation("org.apache.logging.log4j:log4j-core:2.20.0")
+
+  // Testing (optional)
+  testImplementation("org.junit.jupiter:junit-jupiter:5.9.1")
+  testImplementation("dev.restate:sdk-testing:$restateVersion")
+}
+
+// Configure test platform
+tasks.withType<Test> {
+  useJUnitPlatform()
+}
+
+// Set main class
+application {
+  mainClass.set("my.restate.examples.LoanApproval")
+}

java/hello-world-workflow/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.2-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists