import base.props4j.impl.MapProps;

MapProps props = new MapProps();
props.putVal("key1", 1);
props.putVal("key2", "val2");
props.putVal("key3", true);

String strVal_1 = props.strVal("key1"); //"1"
long longVal_1 = props.longVal("key1"); //1L
Boolean boolVal_1 = props.boolVal("key1"); //false

int defVal =  props.intVal("unknown-key", 42); //42

import base.props4j.impl.FileProps;
import java.io.File;

File file = new File("test.properties");
writeToFile(file, "key1 = 1");

FileProps props = new FileProps(file);
int val = props.intVal("key1"); //1

//update file
writeToFile(file, "key1 = 2");

Thread.sleep(...);

int newVal = props.intVal("key1"); //2

import base.props4j.impl.FileProps;
import base.props4j.impl.MultiProps;

MultiProps props = new MultiProps();
props.addSource(new FileProps(file1));
props.addSource(new FileProps(file2));

import base.props4j.DefValKey;

public enum Keys implements DefValKey {
	
	planets_in_solar_system(8),
	is_frog_green(true),
	myName("Evgeny"),
	star_wars_episodes_count(999.999d),
	...
}


MapProps props = new MapProps();
int defVal = Keys.planets_in_solar_system.intFrom(props); //8
		
props.putVal(planets_in_solar_system, 9);
int updatedVal = Keys.planets_in_solar_system.intFrom(props); //9

props.putVal("url", "127.0.0.1");
props.putVal("link1", "${url}/some1");
props.putVal("link2", "${url}/some2");

String link1 = props.strVal("link1"); // 127.0.0.1/some1
String link2 = props.strVal("link2"); // 127.0.0.1/some2