Properties To Settings

Generate at compile time settings classes (java 8) that can load java properties files or HOCON files.

Add the following dependency to your pom:

 <dependencies>
     <dependency>
         <groupId>org.backuity.p2s</groupId>
         <artifactId>p2s</artifactId>
         <version>2.5</version>
     </dependency>
 </dependencies>

Here is an example from the p2s tests:

 import org.p2s.Settings;
 import java.util.Optional;
 
 @Settings
 public interface SomeSettings {
 
     Optional<Integer> timeout();
     String name();
     String theSurname();
 }

You can then automatically load properties file :

 name = John Doe
 timeout = 1234
 the.surname = Toto

With the following code :

SomeSettings settings = JulSettingsFactory.from("your-properties-from-classpath.properties")
                                          .load(SomeSettings.class);

assertEquals("Toto", settings.theSurname());
assertEquals(Optional.of(1234), settings.timeout());

HOCON

The Human-Optimized Config Object Notation files are parsed using https://github.com/typesafehub/config.

To load configuration from an HOCON file add the following dependency to your pom:

 <dependencies>
     <dependency>
         <groupId>org.backuity.p2s</groupId>
         <artifactId>p2s-hocon</artifactId>
         <version>2.5</version>
     </dependency>
 </dependencies>

And use HoconSettingsFactory instead of JulSettingsFactory. So given the following HOCON file :

 name = "John Doe"
 timeout = 1234
 the.surname = "Toto"
 # or alternatively:
 # the { surname = "Toto" }

SomeSettings settings = HoconSettingsFactory.from("your-hoconfrom-classpath.conf")
                                            .load(SomeSettings.class);

assertEquals("Toto", settings.theSurname());
assertEquals(Optional.of(1234), settings.timeout());

This especially shines when used with nested types or arrays.

Basic Types

The following "basic" types are supported:

• Integer and int
• Long and long
• Boolean and boolean
• String

Lists

You can use parameters of type List:

@Settings
public interface ListSettings {
    List<String> languages();
    List<Integer> sizes();
}

Using HOCON:

languages = ["fr", "en", "it"]
sizes = [12, 200, 3]

Or Properties (ids don't have to be sequential):

languages.1 = fr
languages.2 = en
languages.3 = it

sizes.1 = 12
sizes.20 = 200
sizes.300 = 3

Nested types

You can use nested settings interfaces :

@Settings
public interface ParentSettings {
    PersonSettings mother();
    PersonSettings father();
}

public interface PersonSettings {
    String firstName();
    String lastName();
    Integer age();
    AddressSettings address();
}

public interface AddressSettings {
    String city();
    String street();
}

You can load up a Parent with the following HOCON file :

mother {
  first.name = "Mary Jane"
  last.name = "Watson"
  age = 32
  address {
    city = "Manhattan"
    street = "1st avenue"
  }
}

father {
  first { name { "Cab" } }
  last { name { "Calloway" } }
  # ...
}

Or a properties:

mother.first.name = Alice
mother.last.name = Watt
mother.age = 31
mother.address.street = 3 rue de la paix
mother.address.city = Toulon

father.first.name = Bob
# ...

Nested types can also be used in lists:

@Settings
public interface ListSettings {
    List<AddressSettings> addresses();
}

With a HOCON file:

addresses = [{
    city = "Marseille"
    street = "Rue du bourg"
  },{
    city = "NYC"
    street = "1st avenue"
  }]

or with a Properties:

addresses.1.city = Marseille
addresses.1.street = Rue du bourg

addresses.2.city = NYC
addresses.2.street = 1st avenue

Nested types can be optional:

@Settings
public interface OptionalAddressSetting {
    Optional<AddressSettings> address();
}

Fallback

From properties:

SomeSettings settings = JulSettingsFactory.from("your-properties-from-classpath.properties")
    .withFallback("a-fallback-from-classpath.properties")
    .load(SomeSettings.class);

From code:

SomeSettings settings = JulSettingsFactory.from("your-properties-from-classpath.properties")
    .withFallback("the.surname", "Fantastic")
    .withFallback("timeout", "123")
    .load(SomeSettings.class);

Override settings

SomeSettings settings = JulSettingsFactory.from("your-properties-from-classpath.properties")
    .override("the.surname", "Fantastic")
    .override("timeout", "789")
    .load(SomeSettings.class);
     
assertEquals("Fantastic", settings.theSurname());
assertEquals(Optional.of(789), settings.timeout());     

Release

See http://central.sonatype.org/pages/apache-maven.html.

cd p2s

# deploy a snapshot
mvn clean deploy

# perform a release - NOTE : you need to have a published gpg key installed on your system    
# update the version manually - commit push and tag
mvn clean deploy -P release

# promote to central (through the web interface)

Licence

The project is licenced under the Apache 2 licence.