jimmer-sql-graphql-kt

Building GraphQL Services with Jimmer (Kotlin)

English | 中文

Introduction

This example involves multiple features.

The three core features: Fetching Arbitrary Shapes, Saving Arbitrary Shapes, and Arbitrary Complex Queries are bound to be used, so they are not listed in the table below.

Sub-project	Related Feature Documentation Links
model	Using KSP in the project defining entities
	Defining formula-calculated properties
	Defining complex calculated properties
repository	Spring Data-style Repository
rtunime	Cache support
	Global filter
	Pre-save interceptor
	Providing Resolver for calculated properties
service	DTO language
	Using KSP in the project defining DTOs
	Building GraphQL services with Jimmer

Kotlin Symbol Processing

The project depends on the KSP. When opening this project in IntelliJ IDEA for the first time, you may notice that some code that should have been automatically generated is missing. To resolve this, you can choose any of the following methods:

• First, run the ./gradlew build command in the project directory from the command line to generate the code, and then open the project with IntelliJ IDEA.

• Open the project directly with IntelliJ IDEA, ignoring the IDE errors temporarily. After the dependencies are downloaded, run the project's main method. All IDE errors will automatically disappear, and the application will start correctly.

Running Method

After ensuring that the missing code has been generated and recognized by IntelliJ, you can run the example.

The current example supports two running modes:

• Non-caching mode

  This is the default mode, provided for users who want to quickly run and experience the example.

  This mode uses the H2 embedded database, so there is no need to install any external environment. You can directly run service/.../App.kt.

• Caching mode

  This mode is provided to showcase the powerful Jimmer caching and requires external dependencies.

  To better demonstrate its universality, Jimmer provides two external environments.

  • MySQL + Maxwell

    First, install Docker, then execute env-with-cache/maxwell/install.sh to complete the installation.

    Finally, run service/.../App.kt using the Spring profile parameter -Dspring.profiles.active=maxwell or --spring.profiles.active=maxwell.

  • Postgres + Debezium

    First, install Docker, then execute env-with-cache/debezium/install.sh to complete the installation.

    Finally, run service/.../App.kt using the Spring profile parameter -Dspring.profiles.active=debezium or --spring.profiles.active=debezium.

  You only need to choose one of the two environments. If you install both, the Docker containers may encounter errors due to insufficient memory. If you really want to do this, it is recommended to allocate 3GB of memory for Docker.

Regardless of which running mode you use to start the project, you can access the service through http://localhost:8080/graphiql (note the i).

Tenant Identity

To demonstrate the global filter, the Book type in this example uses a multi-tenant mode.

If you want to access the service with a tenant's identity, you need to set the tenant header in the HTTP request, with a value of a or b.

By default, there are only two tenants in the data: a and b. Of course, users can add more tenants.

• For query operations, this HTTP request header is optional. If it is not provided, it will query the books of all tenants.

• For data saving operations, this HTTP request header is required. If it is not provided, the server-side will throw an exception.

You can set the HTTP request header in the bottom-left corner of the http://localhost:8080/graphiql page:

---

⇦ Previous Example ⇦ | ⇧ Back to Parent ⇧ | ⇨ Next Example ⇨