Moved Zeebe client example from Zeebe repository (#3)

see camunda/camunda#9500

.gitignore

@@ -1 +1,4 @@
 .idea
+/zeebe-client/target/
+/zeebe-client/.flattened-pom.xml
+/zeebe-client/zeebe-samples.iml

zeebe-client/README.md

@@ -0,0 +1,8 @@
+# Zeebe Java Client Examples
+
+This Maven project contains a number of examples each performing a specific task using the Zeebe
+Java client.
+
+For an overview and context have a look at
+the [Zeebe documentation](https://docs.camunda.io/docs/product-manuals/clients/java-client-examples/index)
+;

zeebe-client/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<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>
+
+    <artifactId>zeebe-client</artifactId>
+    <groupId>org.camunda.community.examples</groupId>
+    <packaging>jar</packaging>
+    <version>0.0.1-SNAPSHOT</version>
+
+    <name>Zeebe Client Examples</name>
+
+    <properties>
+        <java.version>17</java.version>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+    </properties>
+
+    <dependencies>
+
+        <dependency>
+            <groupId>io.camunda</groupId>
+            <artifactId>zeebe-client-java</artifactId>
+            <version>8.0.3</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.logging.log4j</groupId>
+            <artifactId>log4j-core</artifactId>
+            <version>2.17.2</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.logging.log4j</groupId>
+            <artifactId>log4j-slf4j-impl</artifactId>
+            <version>2.17.2</version>
+        </dependency>
+
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13.2</version>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>3.23.1</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <artifactId>maven-assembly-plugin</artifactId>
+                <configuration>
+                    <descriptorRefs>
+                        <descriptorRef>jar-with-dependencies</descriptorRef>
+                    </descriptorRefs>
+                </configuration>
+                <executions>
+                    <execution>
+                        <id>make-assembly</id>
+                        <goals>
+                            <goal>single</goal>
+                        </goals>
+                        <phase>package</phase>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

zeebe-client/src/main/java/io/camunda/zeebe/example/cluster/TopologyViewer.java

@@ -0,0 +1,74 @@
+/*
+ * Copyright Camunda Services GmbH and/or licensed to Camunda Services GmbH under
+ * one or more contributor license agreements. See the NOTICE file distributed
+ * with this work for additional information regarding copyright ownership.
+ * Licensed under the Zeebe Community License 1.1. You may not use this file
+ * except in compliance with the Zeebe Community License 1.1.
+ */
+package io.camunda.zeebe.example.cluster;
+
+import io.camunda.zeebe.client.ZeebeClient;
+import io.camunda.zeebe.client.ZeebeClientBuilder;
+import io.camunda.zeebe.client.api.response.Topology;
+
+/**
+ * Example application that connects to a cluster on Camunda Cloud, or a locally deployed cluster.
+ *
+ * <p>When connecting to a cluster in Camunda Cloud, this application assumes that the following
+ * environment variables are set:
+ *
+ * <ul>
+ *   <li>ZEEBE_ADDRESS
+ *   <li>ZEEBE_CLIENT_ID
+ *   <li>ZEEBE_CLIENT_SECRET
+ *   <li>ZEEBE_AUTHORIZATION_SERVER_URL
+ * </ul>
+ *
+ * <p><strong>Hint:</strong> When you create client credentials in Camunda Cloud you have the option
+ * to download a file with above lines filled out for you.
+ *
+ * <p>When {@code ZEEBE_ADDRESS} is not set, it connects to a broker running on localhost with
+ * default ports
+ */
+public final class TopologyViewer {
+
+  public static void main(final String[] args) {
+    final String defaultAddress = "localhost:26500";
+    final String envVarAddress = System.getenv("ZEEBE_ADDRESS");
+
+    final ZeebeClientBuilder clientBuilder;
+    final String contactPoint;
+    if (envVarAddress != null) {
+      /* Connect to Camunda Cloud Cluster, assumes that credentials are set in environment variables.
+       * See JavaDoc on class level for details
+       */
+      contactPoint = envVarAddress;
+      clientBuilder = ZeebeClient.newClientBuilder().gatewayAddress(envVarAddress);
+    } else {
+      // connect to local deployment; assumes that authentication is disabled
+      contactPoint = defaultAddress;
+      clientBuilder = ZeebeClient.newClientBuilder().gatewayAddress(defaultAddress).usePlaintext();
+    }
+
+    try (final ZeebeClient client = clientBuilder.build()) {
+      System.out.println("Requesting topology with initial contact point " + contactPoint);
+
+      final Topology topology = client.newTopologyRequest().send().join();
+
+      System.out.println("Topology:");
+      topology
+          .getBrokers()
+          .forEach(
+              b -> {
+                System.out.println("    " + b.getAddress());
+                b.getPartitions()
+                    .forEach(
+                        p ->
+                            System.out.println(
+                                "      " + p.getPartitionId() + " - " + p.getRole()));
+              });
+
+      System.out.println("Done.");
+    }
+  }
+}

zeebe-client/src/main/java/io/camunda/zeebe/example/data/HandleVariablesAsPojo.java

@@ -0,0 +1,116 @@
+/*
+ * Copyright Camunda Services GmbH and/or licensed to Camunda Services GmbH under
+ * one or more contributor license agreements. See the NOTICE file distributed
+ * with this work for additional information regarding copyright ownership.
+ * Licensed under the Zeebe Community License 1.1. You may not use this file
+ * except in compliance with the Zeebe Community License 1.1.
+ */
+package io.camunda.zeebe.example.data;
+
+import io.camunda.zeebe.client.ZeebeClient;
+import io.camunda.zeebe.client.ZeebeClientBuilder;
+import io.camunda.zeebe.client.api.response.ActivatedJob;
+import io.camunda.zeebe.client.api.worker.JobClient;
+import io.camunda.zeebe.client.api.worker.JobHandler;
+import java.util.Scanner;
+
+/**
+ * Example application that connects to a cluster on Camunda Cloud, or a locally deployed cluster.
+ *
+ * <p>When connecting to a cluster in Camunda Cloud, this application assumes that the following
+ * environment variables are set:
+ *
+ * <ul>
+ *   <li>ZEEBE_ADDRESS
+ *   <li>ZEEBE_CLIENT_ID
+ *   <li>ZEEBE_CLIENT_SECRET
+ *   <li>ZEEBE_AUTHORIZATION_SERVER_URL
+ * </ul>
+ *
+ * <p><strong>Hint:</strong> When you create client credentials in Camunda Cloud you have the option
+ * to download a file with above lines filled out for you.
+ *
+ * <p>When {@code ZEEBE_ADDRESS} is not set, it connects to a broker running on localhost with
+ * default ports
+ */
+public final class HandleVariablesAsPojo {
+  public static void main(final String[] args) {
+    final String defaultAddress = "localhost:26500";
+    final String envVarAddress = System.getenv("ZEEBE_ADDRESS");
+
+    final ZeebeClientBuilder clientBuilder;
+    if (envVarAddress != null) {
+      /* Connect to Camunda Cloud Cluster, assumes that credentials are set in environment variables.
+       * See JavaDoc on class level for details
+       */
+      clientBuilder = ZeebeClient.newClientBuilder().gatewayAddress(envVarAddress);
+    } else {
+      // connect to local deployment; assumes that authentication is disabled
+      clientBuilder = ZeebeClient.newClientBuilder().gatewayAddress(defaultAddress).usePlaintext();
+    }
+
+    try (final ZeebeClient client = clientBuilder.build()) {
+      final Order order = new Order();
+      order.setOrderId(31243);
+
+      client
+          .newCreateInstanceCommand()
+          .bpmnProcessId("demoProcess")
+          .latestVersion()
+          .variables(order)
+          .send()
+          .join();
+
+      client.newWorker().jobType("foo").handler(new DemoJobHandler()).open();
+
+      // run until System.in receives exit command
+      waitUntilSystemInput("exit");
+    }
+  }
+
+  private static void waitUntilSystemInput(final String exitCode) {
+    try (final Scanner scanner = new Scanner(System.in)) {
+      while (scanner.hasNextLine()) {
+        final String nextLine = scanner.nextLine();
+        if (nextLine.contains(exitCode)) {
+          return;
+        }
+      }
+    }
+  }
+
+  public static class Order {
+    private long orderId;
+    private double totalPrice;
+
+    public long getOrderId() {
+      return orderId;
+    }
+
+    public void setOrderId(final long orderId) {
+      this.orderId = orderId;
+    }
+
+    public double getTotalPrice() {
+      return totalPrice;
+    }
+
+    public void setTotalPrice(final double totalPrice) {
+      this.totalPrice = totalPrice;
+    }
+  }
+
+  private static class DemoJobHandler implements JobHandler {
+    @Override
+    public void handle(final JobClient client, final ActivatedJob job) {
+      // read the variables of the job
+      final Order order = job.getVariablesAsType(Order.class);
+      System.out.println("new job with orderId: " + order.getOrderId());
+
+      // update the variables and complete the job
+      order.setTotalPrice(46.50);
+
+      client.newCompleteCommand(job.getKey()).variables(order).send();
+    }
+  }
+}

zeebe-client/src/main/java/io/camunda/zeebe/example/job/JobWorkerCreator.java

@@ -0,0 +1,94 @@
+/*
+ * Copyright Camunda Services GmbH and/or licensed to Camunda Services GmbH under
+ * one or more contributor license agreements. See the NOTICE file distributed
+ * with this work for additional information regarding copyright ownership.
+ * Licensed under the Zeebe Community License 1.1. You may not use this file
+ * except in compliance with the Zeebe Community License 1.1.
+ */
+package io.camunda.zeebe.example.job;
+
+import io.camunda.zeebe.client.ZeebeClient;
+import io.camunda.zeebe.client.ZeebeClientBuilder;
+import io.camunda.zeebe.client.api.response.ActivatedJob;
+import io.camunda.zeebe.client.api.worker.JobClient;
+import io.camunda.zeebe.client.api.worker.JobHandler;
+import io.camunda.zeebe.client.api.worker.JobWorker;
+import java.time.Duration;
+import java.util.Scanner;
+
+/**
+ * Example application that connects to a cluster on Camunda Cloud, or a locally deployed cluster.
+ *
+ * <p>When connecting to a cluster in Camunda Cloud, this application assumes that the following
+ * environment variables are set:
+ *
+ * <ul>
+ *   <li>ZEEBE_ADDRESS
+ *   <li>ZEEBE_CLIENT_ID
+ *   <li>ZEEBE_CLIENT_SECRET
+ *   <li>ZEEBE_AUTHORIZATION_SERVER_URL
+ * </ul>
+ *
+ * <p><strong>Hint:</strong> When you create client credentials in Camunda Cloud you have the option
+ * to download a file with above lines filled out for you.
+ *
+ * <p>When {@code ZEEBE_ADDRESS} is not set, it connects to a broker running on localhost with
+ * default ports
+ */
+public final class JobWorkerCreator {
+  public static void main(final String[] args) {
+    final String defaultAddress = "localhost:26500";
+    final String envVarAddress = System.getenv("ZEEBE_ADDRESS");
+
+    final ZeebeClientBuilder clientBuilder;
+    if (envVarAddress != null) {
+      /* Connect to Camunda Cloud Cluster, assumes that credentials are set in environment variables.
+       * See JavaDoc on class level for details
+       */
+      clientBuilder = ZeebeClient.newClientBuilder().gatewayAddress(envVarAddress);
+    } else {
+      // connect to local deployment; assumes that authentication is disabled
+      clientBuilder = ZeebeClient.newClientBuilder().gatewayAddress(defaultAddress).usePlaintext();
+    }
+
+    final String jobType = "foo";
+
+    try (final ZeebeClient client = clientBuilder.build()) {
+
+      System.out.println("Opening job worker.");
+
+      try (final JobWorker workerRegistration =
+          client
+              .newWorker()
+              .jobType(jobType)
+              .handler(new ExampleJobHandler())
+              .timeout(Duration.ofSeconds(10))
+              .open()) {
+        System.out.println("Job worker opened and receiving jobs.");
+
+        // run until System.in receives exit command
+        waitUntilSystemInput("exit");
+      }
+    }
+  }
+
+  private static void waitUntilSystemInput(final String exitCode) {
+    try (final Scanner scanner = new Scanner(System.in)) {
+      while (scanner.hasNextLine()) {
+        final String nextLine = scanner.nextLine();
+        if (nextLine.contains(exitCode)) {
+          return;
+        }
+      }
+    }
+  }
+
+  private static class ExampleJobHandler implements JobHandler {
+    @Override
+    public void handle(final JobClient client, final ActivatedJob job) {
+      // here: business logic that is executed with every job
+      System.out.println(job);
+      client.newCompleteCommand(job.getKey()).send().join();
+    }
+  }
+}