Bahasa JVM

Anda dapat menulis fungsi Anda menggunakan bahasa JVM yang berbeda (seperti Kotlin, Groovy, atau Scala) selama mematuhi aturan berikut:

  • Fungsi ini adalah class publik yang menerapkan salah satu antarmuka fungsi (HttpFunction, BackgroundFunction, atauRawBackgroundFunction ) dan memiliki konstruktor publik tanpa argumen.

  • Jika Anda men-deploy dari sumber:

    • Aplikasi ini dapat dibuat dari Maven.
    • File build berisi semua plugin untuk menghasilkan class yang dikompilasi.

  • Jika Anda men-deploy dari JAR bawaan:

    • Anda bisa menggunakan alat build apa pun untuk menghasilkan JAR ini.
    • JAR bawaan harus berupa Fat JAR dengan semua class dependensinya, atau manifesnya harus berisi entri Class-Path dengan lokasi relatif jar yang berisi class dependensi tersebut.

Contoh fungsi HTTP

Anda menggunakan fungsi HTTP ketika ingin memanggil fungsi melalui permintaan HTTP(S). Contoh berikut menampilkan pesan "Hello World!"

Kotlin

import com.google.cloud.functions.HttpFunction
import com.google.cloud.functions.HttpRequest
import com.google.cloud.functions.HttpResponse
import java.io.IOException
import java.util.logging.Logger

class HelloWorld : HttpFunction {
    // Simple function to return "Hello World"
    @Throws(IOException::class)
    override fun service(request: HttpRequest, response: HttpResponse) {
        response.writer.write("Hello World!")
    }
}

Meriah

import com.google.cloud.functions.HttpFunction
import com.google.cloud.functions.HttpRequest
import com.google.cloud.functions.HttpResponse

class GroovyHelloWorld implements HttpFunction {
    @Override
    void service(HttpRequest request, HttpResponse response) {
        response.writer.write("Hello World!")
    }
}

Scala

class ScalaHelloWorld extends HttpFunction {
  override def service(httpRequest: HttpRequest, httpResponse: HttpResponse): Unit = {
    httpResponse.getWriter.write("Hello World!")
  }
}

File pom.xml untuk contoh HTTP

Berikut adalah file pom.xml untuk contoh di atas:

Kotlin

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.example.functions</groupId>
  <artifactId>functions-kotlin-hello-world</artifactId>


  <properties>
    <maven.compiler.target>11</maven.compiler.target>
    <maven.compiler.source>11</maven.compiler.source>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <kotlin.version>1.9.22</kotlin.version>
  </properties>

  <dependencies>
    <!-- Required for Function primitives -->
    <dependency>
      <groupId>com.google.cloud.functions</groupId>
      <artifactId>functions-framework-api</artifactId>
      <version>1.1.0</version>
      <scope>provided</scope>
    </dependency>

    <dependency>
      <groupId>org.jetbrains.kotlin</groupId>
      <artifactId>kotlin-stdlib-jdk8</artifactId>
      <version>${kotlin.version}</version>
    </dependency>
    <dependency>
      <groupId>org.jetbrains.kotlin</groupId>
      <artifactId>kotlin-test</artifactId>
      <version>${kotlin.version}</version>
      <scope>test</scope>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <!--
          Google Cloud Functions Framework Maven plugin

          This plugin allows you to run Cloud Functions Java code
          locally. Use the following terminal command to run a
          given function locally:

          mvn function:run -Drun.functionTarget=your.package.yourFunction
        -->
        <groupId>com.google.cloud.functions</groupId>
        <artifactId>function-maven-plugin</artifactId>
        <version>0.11.0</version>
        <configuration>
          <functionTarget>functions.HelloWorld</functionTarget>
        </configuration>
      </plugin>
      <plugin>
        <groupId>org.jetbrains.kotlin</groupId>
        <artifactId>kotlin-maven-plugin</artifactId>
        <version>${kotlin.version}</version>
        <executions>
          <execution>
            <id>compile</id>
            <phase>compile</phase>
            <goals>
              <goal>compile</goal>
            </goals>
            <configuration>
              <sourceDirs>
                <source>src/main/kotlin</source>
              </sourceDirs>
            </configuration>
          </execution>
          <execution>
            <id>test-compile</id>
            <phase>test-compile</phase>
            <goals>
              <goal>test-compile</goal>
            </goals>
          </execution>
        </executions>
        <configuration>
          <jvmTarget>1.8</jvmTarget>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>

Meriah

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.example.functions</groupId>
  <artifactId>functions-groovy-hello-world</artifactId>

  <properties>
    <maven.compiler.target>11</maven.compiler.target>
    <maven.compiler.source>11</maven.compiler.source>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <groovy.version>3.0.20</groovy.version>
  </properties>

  <dependencyManagement>
    <dependencies>
      <dependency>
        <artifactId>libraries-bom</artifactId>
        <groupId>com.google.cloud</groupId>
        <scope>import</scope>
        <type>pom</type>
        <version>26.32.0</version>
      </dependency>
    </dependencies>
  </dependencyManagement>

  <dependencies>
    <!-- Required for Function primitives -->
    <dependency>
      <groupId>com.google.cloud.functions</groupId>
      <artifactId>functions-framework-api</artifactId>
      <version>1.1.0</version>
      <scope>provided</scope>
    </dependency>

    <!-- Required for groovy samples -->
    <dependency>
      <groupId>org.codehaus.groovy</groupId>
      <artifactId>groovy-all</artifactId>
      <version>${groovy.version}</version>
      <type>pom</type>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <!--
          Google Cloud Functions Framework Maven plugin

          This plugin allows you to run Cloud Functions Java code
          locally. Use the following terminal command to run a
          given function locally:

          mvn function:run -Drun.functionTarget=your.package.yourFunction
        -->
        <groupId>com.google.cloud.functions</groupId>
        <artifactId>function-maven-plugin</artifactId>
        <version>0.11.0</version>
        <configuration>
          <functionTarget>functions.GroovyHelloWorld</functionTarget>
        </configuration>
      </plugin>
      <plugin>
        <groupId>org.codehaus.gmavenplus</groupId>
        <artifactId>gmavenplus-plugin</artifactId>
        <version>3.0.2</version>
        <executions>
          <execution>
            <id>groovy-compile</id>
            <phase>process-resources</phase>
            <goals>
              <goal>addSources</goal>
              <goal>compile</goal>
            </goals>
          </execution>
        </executions>
        <dependencies>
          <dependency>
            <groupId>org.codehaus.groovy</groupId>
            <artifactId>groovy-all</artifactId>
            <!-- any version of Groovy \>= 1.5.0 should work here -->
            <version>${groovy.version}</version>
            <scope>runtime</scope>
            <type>pom</type>
          </dependency>
        </dependencies>
      </plugin>
    </plugins>
  </build>
</project>

Scala

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.example.functions</groupId>
  <artifactId>functions-scala-hello-world</artifactId>

  <properties>
    <maven.compiler.target>11</maven.compiler.target>
    <maven.compiler.source>11</maven.compiler.source>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencyManagement>
    <dependencies>
      <dependency>
        <artifactId>libraries-bom</artifactId>
        <groupId>com.google.cloud</groupId>
        <scope>import</scope>
        <type>pom</type>
        <version>26.32.0</version>
      </dependency>
    </dependencies>
  </dependencyManagement>

  <dependencies>
    <!-- Required for scala samples -->
    <dependency>
      <groupId>org.scala-lang</groupId>
      <artifactId>scala-library</artifactId>
      <version>2.13.5</version>
    </dependency>

    <!-- Required for Function primitives -->
    <dependency>
      <groupId>com.google.cloud.functions</groupId>
      <artifactId>functions-framework-api</artifactId>
      <version>1.1.0</version>
      <scope>provided</scope>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <!--
          Google Cloud Functions Framework Maven plugin

          This plugin allows you to run Cloud Functions Java code
          locally. Use the following terminal command to run a
          given function locally:

          mvn function:run -Drun.functionTarget=your.package.yourFunction
        -->
        <groupId>com.google.cloud.functions</groupId>
        <artifactId>function-maven-plugin</artifactId>
        <version>0.11.0</version>
        <configuration>
          <functionTarget>functions.ScalaHelloWorld</functionTarget>
        </configuration>
      </plugin>
      <plugin>
        <groupId>net.alchim31.maven</groupId>
        <artifactId>scala-maven-plugin</artifactId>
        <version>4.4.1</version>
        <executions>
          <execution>
            <id>scala-compile</id>
            <phase>process-resources</phase>
            <goals>
              <goal>add-source</goal>
              <goal>compile</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
</project>

Men-deploy fungsi HTTP

Kotlin

gcloud functions deploy kotlin-helloworld --entry-point functions.KotlinHelloWorld --runtime java21 --trigger-http --allow-unauthenticated --memory 512MB

Meriah

gcloud functions deploy groovy-helloworld --entry-point functions.GroovyHelloWorld --runtime java21 --trigger-http --allow-unauthenticated --memory 512MB

Scala

gcloud functions deploy scala-helloworld --entry-point functions.ScalaHelloWorld --runtime java21 --trigger-http --allow-unauthenticated --memory 512MB

Contoh fungsi berbasis peristiwa

Anda menggunakan fungsi berbasis peristiwa saat ingin Cloud Run Function dipanggil secara tidak langsung sebagai respons terhadap peristiwa asinkron, seperti pesan pada topik Pub/Sub, perubahan dalam bucket Cloud Storage, atau peristiwa Firebase.

Ada dua jenis fungsi berbasis peristiwa: fungsi latar belakang dan fungsi CloudEvent. Bahasa JVM hanya mendukung fungsi latar belakang.

Kotlin

import com.google.cloud.functions.BackgroundFunction
import com.google.cloud.functions.Context
import functions.eventpojos.PubsubMessage
import java.nio.charset.StandardCharsets
import java.util.Base64
import java.util.logging.Logger


class KotlinHelloPubSub : BackgroundFunction<PubsubMessage> {
    override fun accept(message: PubsubMessage, context: Context) {
        // name's default value is "world"
        var name = "world"
        if (message?.data != null) {
            name = String(
                    Base64.getDecoder().decode(message.data!!.toByteArray(StandardCharsets.UTF_8)),
                    StandardCharsets.UTF_8)
        }
        LOGGER.info(String.format("Hello %s!", name))
        return;
    }

    companion object {
        private val LOGGER = Logger.getLogger(KotlinHelloPubSub::class.java.name)
    }
}

Saat mengembangkan fungsi latar belakang, Anda menentukan class untuk peristiwa yang memicu fungsi Anda. Namun, marshalling GSON mungkin tidak langsung berfungsi untuk Kotlin, jika class peristiwa Anda tidak mengikuti panduan tertentu.

Di class peristiwa Kotlin, properti harus mematuhi panduan ini:

  • Parameter dapat disetel ke null.
  • Tidak ada nilai default yang ditetapkan padanya.
  • Properti tersebut bukan properti delegasi.

Pendekatan lainnya adalah membuat class peristiwa di Java, dan menggunakannya dari class fungsi Kotlin Anda.

Meriah

import com.google.cloud.functions.BackgroundFunction
import com.google.cloud.functions.Context
import functions.eventpojos.PubsubMessage
import java.nio.charset.StandardCharsets
import java.util.logging.Logger

class GroovyHelloPubSub implements BackgroundFunction<PubsubMessage> {
    private static final Logger LOGGER = Logger.getLogger(GroovyHelloPubSub.class.name)

    @Override
    void accept(PubsubMessage message, Context context) {
        // name's default value is "world"
        String name = "world"

        if (message?.data) {
             name = new String(Base64.decoder.decode(message.data), StandardCharsets.UTF_8)
        }

        LOGGER.info("Hello ${name}!")
        return
    }
}

Scala

import java.nio.charset.StandardCharsets
import java.util.Base64
import java.util.logging.Logger

import com.google.cloud.functions.{BackgroundFunction, Context}
import functions.eventpojos.PubsubMessage

class ScalaHelloPubSub extends BackgroundFunction[PubsubMessage] {

  val LOGGER = Logger.getLogger(this.getClass.getName)

  override def accept(message: PubsubMessage, context: Context): Unit = {
    // name's default value is "world"
    var name = "world"
    if (message != null && message.getData != null) {
      name = new String(Base64.getDecoder.decode(
        message.getData.getBytes(StandardCharsets.UTF_8)), StandardCharsets.UTF_8)
    }
    LOGGER.info(String.format("Hello %s!", name))
  }
}

Men-deploy fungsi latar belakang

Kotlin

gcloud functions deploy kotlin-hello-pubsub --entry-point functions.KotlinHelloPubSub --runtime java21 --trigger-topic my-topic --allow-unauthenticated --memory 512MB

Meriah

gcloud functions deploy groovy-hello-pubsub --entry-point functions.GroovyHelloPubSub --runtime java21 --trigger-topic my-topic --allow-unauthenticated --memory 512MB

Scala

gcloud functions deploy scala-hello-pubsub --entry-point functions.ScalaHelloPubSub --runtime java21 --trigger-topic my-topic --allow-unauthenticated --memory 512MB

Menguji contoh latar belakang

Anda dapat menguji contoh latar belakang sebagai berikut:

  1. Publikasikan pesan ke Topik Pub/Sub untuk memicu fungsi Anda:

    gcloud pubsub topics publish my-topic --message Flurry

  2. Lihat log:

    gcloud functions logs read --limit 10

Anda akan melihat sesuatu seperti ini, dengan pesan yang menyertakan nama yang Anda publikasikan ke topik Pub/Sub:

D      my-function  ...  Function execution started
I      my-function  ...  Hello Flurry!
D      my-function  ...  Function execution took 39 ms, finished with status: 'ok'