Formatting Java code snippets (#424)

README.md

@@ -76,6 +76,20 @@ Code snippets will be compiled and build on PRs and releases.
 
 Details on how code snippets are parsed and inserted can be found in the [code-loader.js](src/plugins/code-loader.js) file.
 
+### Code formatting
+We use Spotless for formatting the Java code snippets. 
+However, Spotless is quite eager on merging lines together into longer lines. 
+This doesn't work well for the documentation sometimes because it requires horizontal scrolling.
+If you don't want Spotless to merge lines on formatting use `// break` in between the lines.
+The code loader will filter these out and the formatter will respect the breaks:
+```java
+RestateHttpEndpointBuilder.builder()
+    // break
+    .bind(new TicketObject())
+    // break
+    .buildAndListen();
+```
+
 ## Releasing the documentation
 
 Before releasing the documentation, update schemas and version of Restate artifacts, either:

code_snippets/java/build.gradle.kts

@@ -1,49 +1,61 @@
 import java.net.URI
 
 plugins {
-  java
-  application
+    java
+    application
+    id("com.diffplug.spotless") version "6.25.0"
 }
 
 repositories {
-  mavenCentral()
+    mavenCentral()
 }
 
 val restateVersion = "1.0.1"
 
 dependencies {
-  // Restate SDK
-  annotationProcessor("dev.restate:sdk-api-gen:$restateVersion")
-  implementation("dev.restate:sdk-api:$restateVersion")
-  implementation("dev.restate:sdk-common:$restateVersion")
-  implementation("dev.restate:sdk-http-vertx:$restateVersion")
-  implementation("dev.restate:sdk-lambda:$restateVersion")
-  implementation("dev.restate:sdk-serde-jackson:$restateVersion")
-
-  // Jackson parameter names
-  // https://github.com/FasterXML/jackson-modules-java8/tree/2.14/parameter-names
-  implementation("com.fasterxml.jackson.module:jackson-module-parameter-names:2.16.1")
-  // Jackson java8 types
-  implementation("com.fasterxml.jackson.datatype:jackson-datatype-jdk8:2.16.1")
-  implementation("com.fasterxml.jackson.datatype:jackson-datatype-jsr310:2.16.1")
-
-  implementation("dev.restate:sdk-serde-protobuf:$restateVersion")
-  implementation("org.apache.logging.log4j:log4j-core:2.20.0")
+    // Restate SDK
+    annotationProcessor("dev.restate:sdk-api-gen:$restateVersion")
+    implementation("dev.restate:sdk-api:$restateVersion")
+    implementation("dev.restate:sdk-common:$restateVersion")
+    implementation("dev.restate:sdk-http-vertx:$restateVersion")
+    implementation("dev.restate:sdk-lambda:$restateVersion")
+    implementation("dev.restate:sdk-serde-jackson:$restateVersion")
+
+    // Jackson parameter names
+    // https://github.com/FasterXML/jackson-modules-java8/tree/2.14/parameter-names
+    implementation("com.fasterxml.jackson.module:jackson-module-parameter-names:2.16.1")
+    // Jackson java8 types
+    implementation("com.fasterxml.jackson.datatype:jackson-datatype-jdk8:2.16.1")
+    implementation("com.fasterxml.jackson.datatype:jackson-datatype-jsr310:2.16.1")
+
+    implementation("dev.restate:sdk-serde-protobuf:$restateVersion")
+    implementation("org.apache.logging.log4j:log4j-core:2.20.0")
 }
 
 java {
-  toolchain {
-    languageVersion.set(JavaLanguageVersion.of(21))
-  }
+    toolchain {
+        languageVersion.set(JavaLanguageVersion.of(21))
+    }
 }
 
 tasks.withType<JavaCompile> {
-  // Using -parameters allows to use Jackson ParameterName feature
-  // https://github.com/FasterXML/jackson-modules-java8/tree/2.14/parameter-names
-  options.compilerArgs.add("-parameters")
+    // Using -parameters allows to use Jackson ParameterName feature
+    // https://github.com/FasterXML/jackson-modules-java8/tree/2.14/parameter-names
+    options.compilerArgs.add("-parameters")
 }
 
 // Set main class
 application {
-  mainClass.set("develop.Greeter")
+    mainClass.set("develop.Greeter")
+}
+
+
+spotless {
+    java {
+        googleJavaFormat()
+        importOrder()
+        removeUnusedImports()
+        formatAnnotations()
+        toggleOffOn("//", "/n")
+    }
 }

code_snippets/java/src/main/java/concepts/buildingblocks/AppMain.java

@@ -1,10 +1,12 @@
 package concepts.buildingblocks;
 
-import concepts.buildingblocks.part0.OrderWorkflow;
 import dev.restate.sdk.http.vertx.RestateHttpEndpointBuilder;
 
 public class AppMain {
-    public static void main(String[] args) {
-        RestateHttpEndpointBuilder.builder().bind(new OrderWorkflow()).bind(new DeliveryManager()).buildAndListen();
-    }
+  public static void main(String[] args) {
+    RestateHttpEndpointBuilder.builder()
+        .bind(new OrderWorkflow())
+        .bind(new DeliveryManager())
+        .buildAndListen();
+  }
 }

code_snippets/java/src/main/java/concepts/buildingblocks/DeliveryManager.java

@@ -8,8 +8,6 @@
 @VirtualObject
 public class DeliveryManager {
 
-    @Handler
-    public void startDelivery(ObjectContext ctx, OrderRequest order) {
-
-    }
+  @Handler
+  public void startDelivery(ObjectContext ctx, OrderRequest order) {}
 }

code_snippets/java/src/main/java/concepts/buildingblocks/OrderWorkflow.java

@@ -0,0 +1,81 @@
+package concepts.buildingblocks;
+
+import concepts.buildingblocks.types.OrderRequest;
+import concepts.buildingblocks.types.StatusEnum;
+import concepts.buildingblocks.utils.PaymentClient;
+import concepts.buildingblocks.utils.RestaurantClient;
+import dev.restate.sdk.JsonSerdes;
+import dev.restate.sdk.ObjectContext;
+import dev.restate.sdk.annotation.Handler;
+import dev.restate.sdk.annotation.VirtualObject;
+import dev.restate.sdk.common.Serde;
+import dev.restate.sdk.common.StateKey;
+import dev.restate.sdk.serde.jackson.JacksonSerdes;
+import java.time.Duration;
+
+// <start_here>
+@VirtualObject
+public class OrderWorkflow {
+  public static final StateKey<StatusEnum> STATUS =
+      StateKey.of("status", JacksonSerdes.of(StatusEnum.class));
+
+  // <mark_1>
+  @Handler
+  public void process(ObjectContext ctx, OrderRequest order) {
+    // </mark_1>
+    String id = order.getOrderId();
+    // <mark_4>
+    ctx.set(STATUS, StatusEnum.CREATED);
+    // </mark_4>
+
+    // 2. Handle payment
+    // <mark_5>
+    String token = ctx.random().nextUUID().toString();
+    boolean paid =
+        ctx.run(
+            JsonSerdes.BOOLEAN,
+            // break
+            () -> PaymentClient.charge(id, token, order.getTotalCost()));
+    // </mark_5>
+
+    if (!paid) {
+      // <mark_4>
+      ctx.set(STATUS, StatusEnum.REJECTED);
+      // </mark_4>
+      return;
+    }
+
+    // 3. Schedule preparation
+    // <mark_4>
+    ctx.set(STATUS, StatusEnum.SCHEDULED);
+    // </mark_4>
+    ctx.sleep(Duration.ofMillis(order.getDeliveryDelay()));
+
+    // 4. Trigger preparation
+    // <mark_3>
+    var awakeable = ctx.awakeable(Serde.VOID);
+    // <mark_5>
+    ctx.run(() -> RestaurantClient.prepare(id, awakeable.id()));
+    // </mark_5>
+    // </mark_3>
+    // <mark_4>
+    ctx.set(STATUS, StatusEnum.IN_PREPARATION);
+    // </mark_4>
+
+    // <mark_3>
+    awakeable.await();
+    // </mark_3>
+    // <mark_4>
+    ctx.set(STATUS, StatusEnum.SCHEDULING_DELIVERY);
+    // </mark_4>
+
+    // 5. Find a driver and start delivery
+    // <mark_2>
+    DeliveryManagerClient.fromContext(ctx, id).startDelivery(order).await();
+    // </mark_2>
+    // <mark_4>
+    ctx.set(STATUS, StatusEnum.DELIVERED);
+    // </mark_4>
+  }
+}
+// <end_here>