Defining a blog service

• What you need
• 1. Create a Thrift file
• 2. Define a service
• 3. Compile the Thrift file
• Next step

Let's begin by defining our blog service in a Thrift file.

What you need

No preparation is required for this step. Do check that you've prepared the prerequisites.

1. Create a Thrift file

Create a Thrift file, blog.thrift in the {project_root}/src/main/thrift folder as follows. You can see the full version of the file here.

namespace java example.armeria.blog.thrift

2. Define a service

Let's define our blog service in the blog.thrift file. We'll add structs, an exception, and service methods.

1. Add the BlogPost struct.

   blog.thrift

   struct BlogPost {
     1: i32 id;
     2: string title;
     3: string content;
     4: i64 createdAt;
     5: i64 modifiedAt;
   }

2. Add structs for request and response objects as follows.

   blog.thrift

   struct CreateBlogPostRequest {
     1: string title;
     2: string content;
   }
   
   struct GetBlogPostRequest {
     1: i32 id;
   }
   
   struct ListBlogPostsRequest {
     1: bool descending;
   }
   
   struct ListBlogPostsResponse {
     1: list<BlogPost> blogs;
   }
   
   struct UpdateBlogPostRequest {
     1: i32 id;
     2: string title;
     3: string content;
   }
   
   struct DeleteBlogPostRequest {
     1: i32 id;
   }

3. Add the BlogNotFoundException.

   blog.thrift

   exception BlogNotFoundException {
     1: string reason
   }

4. Add a service with methods for create, read, update, and delete operations.

   blog.thrift

   service BlogService {
     BlogPost createBlogPost(1:CreateBlogPostRequest request),
   
     BlogPost getBlogPost(1:GetBlogPostRequest request) throws (1:BlogNotFoundException e),
   
     ListBlogPostsResponse listBlogPosts(1:ListBlogPostsRequest request),
   
     BlogPost updateBlogPost(1:UpdateBlogPostRequest request) throws (1:BlogNotFoundException e),
   
     void deleteBlogPost(1:DeleteBlogPostRequest request) throws (1:BlogNotFoundException e),
   }

3. Compile the Thrift file

Compile the blog.thrift file to generate Java code. You can refer to the full build.gradle file for generating code with Gradle Thrift Plugin.

./gradlew compileThrift

You'll see the generated Java code in the {project_root}/build/generated-sources/thrift/gen-java/example/armeria/blog/thrift/ folder.

Next step

In this step, we've defined a Thrift file for our service and generated Java code. Next, we'll run a service and test the connection.