Fix nexus sample TLS settings (temporalio#688)

Author: Quinn-With-Two-Ns

core/src/main/java/io/temporal/samples/nexus/README.MD

@@ -54,7 +54,7 @@ temporal operator nexus endpoint create \
   --name my-nexus-endpoint-name \
   --target-namespace my-target-namespace \
   --target-task-queue my-handler-task-queue \
-  --description-file ./service/description.md
+  --description-file ./core/src/main/java/io/temporal/samples/nexus/service/description.md
 ```
 
 ## Getting started with a self-hosted service or Temporal Cloud

core/src/main/java/io/temporal/samples/nexus/options/ClientOptions.java

@@ -19,6 +19,7 @@
 
 package io.temporal.samples.nexus.options;
 
+import io.grpc.netty.shaded.io.grpc.netty.GrpcSslContexts;
 import io.grpc.netty.shaded.io.netty.handler.ssl.SslContextBuilder;
 import io.grpc.netty.shaded.io.netty.handler.ssl.util.InsecureTrustManagerFactory;
 import io.temporal.client.WorkflowClient;
@@ -27,13 +28,11 @@
 import io.temporal.serviceclient.WorkflowServiceStubsOptions;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
-import java.util.Arrays;
 import javax.net.ssl.SSLException;
 import org.apache.commons.cli.*;
 
 public class ClientOptions {
   public static WorkflowClient getWorkflowClient(String[] args) {
-    System.out.println(Arrays.toString(args));
     Options options = new Options();
     Option targetHostOption = new Option("target-host", true, "Host:port for the Temporal service");
     targetHostOption.setRequired(false);
@@ -107,7 +106,7 @@ public static WorkflowClient getWorkflowClient(String[] args) {
         if (insecureSkipVerify) {
           sslContext.trustManager(InsecureTrustManagerFactory.INSTANCE);
         }
-        serviceStubOptionsBuilder.setSslContext(sslContext.build());
+        serviceStubOptionsBuilder.setSslContext(GrpcSslContexts.configure(sslContext).build());
       } catch (SSLException e) {
         throw new RuntimeException(e);
       } catch (FileNotFoundException e) {

core/src/main/java/io/temporal/samples/nexus/service/description.md

@@ -1,8 +1,8 @@
 Service Name:
-my-hello-service
+NexusService
 Operation Names:
 echo
-say-hello
+hello
 
 Input / Output arguments are in the following repository:
 https://github.com/temporalio/samples-java/core/src/main/java/io/temporal/samples/nexus/service/NexusService.java