Running a service

• What you need
• 1. Implement the service
• 2. Override service methods
• 3. Create a server
• 4. Run the server
• What's next

In this step, we'll do three things with the code we obtained from our Thrift file; define the blog service in Java, create a server instance, and run the service.

What you need

You need to have the generated Java code obtained from the previous step. You can always download the full version, instead of creating one yourself.

1. Implement the service

Create a file, BlogServiceImpl.java, and declare the BlogServiceImpl class implementing the BlogService service we defined earlier in Step 1. Define a service.

package example.armeria.server.blog.thrift;

import example.armeria.blog.thrift.BlogService;

public class BlogServiceImpl implements BlogService.AsyncIface {}

2. Override service methods

Add empty service methods as follows to override the service methods. We'll implement the service methods one by one in this tutorial. Let's leave them empty for now.

import example.armeria.blog.thrift.BlogPost;
import example.armeria.blog.thrift.CreateBlogPostRequest;
import example.armeria.blog.thrift.GetBlogPostRequest;
import example.armeria.blog.thrift.ListBlogPostsRequest;
import example.armeria.blog.thrift.ListBlogPostsResponse;
import example.armeria.blog.thrift.UpdateBlogPostRequest;
import example.armeria.blog.thrift.DeleteBlogPostRequest;
import org.apache.thrift.TException;
import org.apache.thrift.async.AsyncMethodCallback;

public class BlogServiceImpl implements BlogService.AsyncIface {

  @Override
  public void createBlogPost(CreateBlogPostRequest request, AsyncMethodCallback<BlogPost> resultHandler)
          throws TException {}

  @Override
  public void getBlogPost(GetBlogPostRequest request, AsyncMethodCallback<BlogPost> resultHandler)
          throws TException {}

  @Override
  public void listBlogPosts(ListBlogPostsRequest request, AsyncMethodCallback<ListBlogPostsResponse> resultHandler)
          throws TException {}

  @Override
  public void updateBlogPost(UpdateBlogPostRequest request, AsyncMethodCallback<BlogPost> resultHandler)
          throws TException {}

  @Override
  public void deleteBlogPost(DeleteBlogPostRequest request, AsyncMethodCallback<Void> resultHandler)
          throws TException {}
}

3. Create a server

Let's create a server to serve our service.

1. Create the Main class for the server. You can see the full version of the file here.

   Main.java

   package example.armeria.server.blog.thrift;
   
   import org.slf4j.Logger;
   import org.slf4j.LoggerFactory;
   
   public final class Main {
     private static final Logger logger = LoggerFactory.getLogger(Main.class);
   }

2. Add the newServer() method in the Main class as follows. We are using Armeria's THttpService to handle Thrift calls.

   Main.java

   import com.linecorp.armeria.server.Server;
   import com.linecorp.armeria.server.thrift.THttpService;
   ...
   private static Server newServer(int port) throws Exception {
     final THttpService tHttpService =
               THttpService.builder()
                           .addService(new BlogServiceImpl())
                           .build();
   }

3. Create and return a server instance using Armeria's ServerBuilder. Note that the service instance, tHttpService, is added to the server instance.

   Main.java

   private static Server newServer(int port) throws Exception {
     ...
     return Server.builder()
                  .http(port)
                  .service("/thrift", tHttpService) // Add the service to server
                  .build();
   }

4. Add the main() method in the Main class as follows.

   Main.java

   public static void main(String[] args) throws Exception {
     final Server server = newServer(8080);
   
     server.closeOnJvmShutdown().thenRun(() -> {
       logger.info("Server has been stopped.");
     });
   
     server.start().join();
   }

4. Run the server

Run the Main.main() method on your IDE or using Gradle.

./gradlew run

Your server is running if you see the following message.

[armeria-boss-http-*:8080] INFO com.linecorp.armeria.server.Server - Serving HTTP at /[0:0:0:0:0:0:0:0]:8080 - http://127.0.0.1:8080/

What's next

In this step, we've created and added an empty Thrift service to a server.

Next, we'll get on with implementing a service method for creating blog posts.