PropertiesMapper

A java library to map the values from java.util.Properties objects (most likely read from .properties files for configuration) to abitrary java Object fields using annotations and reflection.

Supported field types are String, Long, Integer, Double, Float, Boolean and their primitive equivalents.

The library has no external dependencies and can be build using ant and Java 1.7. Previous java versions down to 1.5 should work, too, but are not yet tested and thus not enabled in the project properties. Feel free to report success when compiling with Java < 1.7!

Usage example (based on a simple TinkerForge configuration):

config.properties - A .properties file containing data:

tinker.daemon.host=10.1.2.3
tinker.daemon.port=4223
tinker.display.uid=aa1
tinker.temperature.uid=bb2

TinkerConfig.java - An object to hold the property values

public class TinkerConfig {
    @Property("tinker.daemon.host")
    private String brickDaemonHost;
    
    @Property("tinker.daemon.port")
    private Integer brickDaemonPort;
    
    @Property("tinker.temperature.uid")
    private String temperaturBrickletUid;
    
    @Property("tinker.display.uid")
    private String displayBrickletUid;
...
}

To map the contents of a Properties object to an arbitrary object (for our example, loadProperties() loads the config.properties file and myAnnotatedObject is an instance of TinkerConfig):

Properties p = loadProperties(); // you still need to do this by yourself, don't care where the properties come from
PropertiesMapper.mapPropertiesToObject(p, myAnnotatedObject); // values from the p are written to myConfigObject based on the @Property annotations

To map the field values from an Object back to a Properties instance:

Properties p = new Properties();
PropertiesMapper.mapObjectToProperties(myAnnotatedObject, p);