rename akka-docs dir to docs (#62)

docs/src/test/java/jdocs/cluster/ClusterDocTest.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2015-2022 Lightbend Inc. <https://www.lightbend.com>
+ */
+
+package jdocs.cluster;
+
+import org.apache.pekko.testkit.javadsl.TestKit;
+import com.typesafe.config.ConfigFactory;
+
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Set;
+import jdocs.AbstractJavaTest;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+// #join-seed-nodes-imports
+import org.apache.pekko.actor.Address;
+import org.apache.pekko.cluster.Cluster;
+
+// #join-seed-nodes-imports
+import org.apache.pekko.actor.ActorSystem;
+import org.apache.pekko.cluster.Member;
+
+public class ClusterDocTest extends AbstractJavaTest {
+
+  static ActorSystem system;
+
+  @BeforeClass
+  public static void setup() {
+    system =
+        ActorSystem.create(
+            "ClusterDocTest",
+            ConfigFactory.parseString(scala.docs.cluster.ClusterDocSpec.config()));
+  }
+
+  @AfterClass
+  public static void tearDown() {
+    TestKit.shutdownActorSystem(system);
+    system = null;
+  }
+
+  @Test
+  public void demonstrateLeave() {
+    // #leave
+    final Cluster cluster = Cluster.get(system);
+    cluster.leave(cluster.selfAddress());
+    // #leave
+
+  }
+
+  // compile only
+  @SuppressWarnings("unused")
+  public void demonstrateDataCenter() {
+    // #dcAccess
+    final Cluster cluster = Cluster.get(system);
+    // this node's data center
+    String dc = cluster.selfDataCenter();
+    // all known data centers
+    Set<String> allDc = cluster.state().getAllDataCenters();
+    // a specific member's data center
+    Member aMember = cluster.state().getMembers().iterator().next();
+    String aDc = aMember.dataCenter();
+    // #dcAccess
+  }
+
+  // compile only
+  @SuppressWarnings("unused")
+  public void demonstrateJoinSeedNodes() {
+    // #join-seed-nodes
+    final Cluster cluster = Cluster.get(system);
+    List<Address> list =
+        new LinkedList<>(); // replace this with your method to dynamically get seed nodes
+    cluster.joinSeedNodes(list);
+    // #join-seed-nodes
+  }
+}