spring-autoproperties

A Spring plugin to automatically generate implementations of interfaces using @Value annotations. This is handy for organising multiple related properties into a single beans without needing to implement the bean itself.

Installation

Get the jar through Maven:

<dependency>
    <groupId>com.mdaniline</groupId>
    <artifactId>spring-autoproperties</artifactId>
    <version>1.0.1</version>
</dependency>

Dependencies

• Java 1.6+
• Spring 4.2+

Usage

1. Annotate your application config bean with @EnableAutoProperties. You will need to specify the basePackages and/or basePackageClasses properties to configure which packages should be scanned.
2. Create an interface which you want to proxy and annotate it with @AutoProperties. Every method should be in getter-style (non-void return value and no parameters) and annotated with @Value. For example:

@AutoProperties
public interface DatabaseSettings {

    @Value("${db.connectionString}")
    String getConnectionString();

    @Value("${db.username}")
    String getUsername();

    @Value("${db.password}")
    String getPassword();

    @Value("${db.pool.maxActive}")
    Integer getMaxActiveConnections();
}

Why would I bother?

You can now inject this single interface into your beans instead of a long, messy list of properties, e.g.

public class CustomDataSource {
    @Autowired
    public CustomDataSource(DatabaseSettings settings) {
        ...
    }
    ...
}

instead of

public class CustomDataSource {
    @Autowired
    public CustomDataSource(@Value("${db.connectionString}") String connectionString,
                            @Value("${db.username}") String username,
                            @Value("${db.password}") String password,
                            @Value("${db.pool.maxActive}") Integer maxActiveConnections) {
        ...
    }
    ...
}