spring-data-sqlfile

spring-data-sqlfile is a Java library that allows you to move large SQL queries from your Spring Data JPA @Query annotations into separate .sql files in your resources folder. This keeps your Java code clean and allows you to use SQL syntax highlighting and formatting in your IDE.

Why use spring-data-sqlfile?

• Clean Code: No more multiline strings or messy SQL inside Java annotations.
• IDE Support: Full SQL syntax highlighting, auto-completion, and formatting for your queries.
• Maintainability: Manage complex queries as separate files.
• Automatic Generation: Uses annotation processing to generate the final repository at compile-time.

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Installation

1. Maven Central (Recommended)

Add the following dependency to your pom.xml:

<dependency>
    <groupId>io.github.veinhorn</groupId>
    <artifactId>sqlfile-processor</artifactId>
    <version>0.1.0</version>
</dependency>

2. JitPack

This library is also available via JitPack.

1. Add JitPack repository

Add this to your pom.xml:

<repositories>
    <repository>
        <id>jitpack.io</id>
        <url>https://jitpack.io</url>
    </repository>
</repositories>

2. Add dependency

<dependency>
    <groupId>com.github.VEINHORN.spring-data-sqlfile</groupId>
    <artifactId>sqlfile-processor</artifactId>
    <version>v0.1.0</version>
</dependency>

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How it Works

The library uses an Annotation Processor to scan your interfaces marked with @Repository. For every method annotated with @SqlFromResource, it reads the specified SQL file from your resources and generates a new interface (defaulting to the original name + Impl postfix) containing the @Query annotation with the injected SQL.

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Quick Start

1. Define your Repository

Create an interface and annotate its methods with @SqlFromResource. Provide the path to your SQL file relative to the resources folder.

@Repository
public interface UserRepository extends JpaRepository<User, Integer> {
    @SqlFromResource(path = "sql/find_all_users.sql")
    List<User> findAll();

    @SqlFromResource(path = "sql/find_by_id.sql")
    User findByUserId(Integer userId);
}

2. Create SQL files

Place your SQL files in src/main/resources/sql/.

src/main/resources/sql/find_all_users.sql:

SELECT * FROM users;

src/main/resources/sql/find_by_id.sql:

SELECT * FROM users WHERE id = :userId;

3. Compile your project

Run mvn clean compile. The annotation processor will generate UserRepositoryImpl in the target/generated-sources directory.

4. Use the generated Repository

In your service, inject the generated UserRepositoryImpl interface:

@Service
public class UserService {
    @Autowired
    private UserRepositoryImpl repository; // Note the 'Impl' postfix

    public List<User> getAllUsers() {
        return repository.findAll();
    }
}

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Configuration

Customizing the Class Postfix

By default, the processor appends Impl to the generated interface name. You can customize this in your maven-compiler-plugin configuration:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.8.0</version>
    <configuration>
        <compilerArgs>
            <arg>-AclassPostfix=Generated</arg>
        </compilerArgs>
    </configuration>
</plugin>

Now the generated interface will be named UserRepositoryGenerated.

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Example

For a complete working setup, check out the example module.

License

This project is licensed under the MIT License - see the LICENSE file for details.