Example

Create an interface for your config object:

public interface MyConfig
{
    @Config("foo")
    String getFoo();

    @Config("blah")
    int getBlah();

    @Config("what")
    @Default("none")
    String getWhat();
}

Set the properties that we mapped with @Config above (or simply call System.getProperties()):

Properties props = new Properties();
props.setProperty("foo", "hello");
props.setProperty("blah", "123");

Then create the config object from the properties:

ConfigurationObjectFactory factory = new ConfigurationObjectFactory(props);
MyConfig conf = factory.build(MyConfig.class);

Default values

Using @Default() can set arbitrary default values. To set null as the default value, use the @DefaultNullannotation.

Advanced usage

    @Config({"what1", "what2"})
    @Default("none")
    String getWhat();

will look at what1 first, then at what2 and finally fall back to the default.

Parameterized configs

    enum StateType {
       FILESYSTEM,
       MEMORY
    }
    
    @Config("${state_type}.size")
    @DefaultNull
    String getParameterizedConfig(@Param("state_type") StateType e);
    
    @Config("${state_type}.${source}.path")
    @DefaultNull
    String getDoubleParameterizedConfig(@Param("state_type") StateType e, @Param("source") String source);

Use it like the following:

    myConfig.getParameterizedConfig(StateType.MEMORY);   // reads from MEMORY.size
    myConfig.getDoubleParameterizedConfig(StateType.FILESYSTEM, "backend");  // reads from FILESYSTEM.backend.path

Type support

Config-magic supports these types:

• Primitive types: boolean, byte, short, integer, long, float, double.
• Enums. Note that config-magic by default ignores the case for enum values.
• java.lang.String.
• java.net.URI.
• java.lang.Class and simple wildcard extensions (java.lang.Class<?>, java.lang.Class<? extends Foo> - config-magic will type check that the type passed as a property conforms to the wildcard type), but not more complex wildcard or parameterized types (e.g. java.lang.Class<? super Bar> or java.lang.Class<? extends List<? super Bar>>).
• org.skipe.config.TimeSpan: constructed from short textual representation like "5d" (or alias "5 days"); units supported are:
• ms (alias 'milliseconds')
• s ('seconds')
• m ('minutes')
• h ('hours')
• d ('days')
• Any instantiable class that has a public constructor with a single Object parameter. This is useful for instance for joda-time's DateTime objects.
• Any instantiable class that has a public constructor with a single String parameter. This is useful for instance for java.lang.File.
• Any class that has a static valueOf method with a single String parameter and the class as its return type.

Maven dependency

To use config-magic in Maven projects:

<dependency>
    <groupId>org.skife.config</groupId>
    <artifactId>config-magic</artifactId>
    <version>0.11</version>
</dependency>

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