Typesafe property api

api.java

public class Property<T> {

  protected final String name;

  public Property(String name) {
    this.name = name;
  }

  public String toString() {
    return name;
  }
}


public class PropertyMap<K, V> {

  protected final String name;

  public PropertyMap(String name) {
    this.name = name;
  }

  public String getName() {
    return name;
  }

}


public class PropertyList<T> {

  protected final String name;

  public PropertyList(String name) {
    this.name = name;
  }

  public String toString() {
    return name;
  }
}



public class Properties {

  protected Map<Object, Object> properties = new HashMap<>();

  public <T> T get(Property<T> property) {
    return (T) properties.get(property);
  }

  public <T> List<T> get(PropertyList<T> property) {
    return (List<T>) properties.get(property);
  }

  public <K,V> Map<K,V> get(PropertyMap<K,V> property) {
    return (Map<K,V>) properties.get(property);
  }

  public <T> void addListItem(PropertyList<T> property, T value) {
    List<T> list = get(property);
    if(list == null) {
      list = new ArrayList<>();
      set(property, list);
    }
    list.add(value);
  }

  public <T> void set(Property<T> property, T value) {
    properties.put(property, value);
  }

  public <T> void set(PropertyList<T> property, List<T> value) {
    properties.put(property, value);
  }

  public <K, V> void putMapEntry(PropertyMap<K,V> property, K key, V value) {
    Map<K,V> map = get(property);
    if(map == null) {
      map = new HashMap<>();
      properties.put(property, map);
    }
    map.put(key, value);
  }

  public boolean contains(Property<?> property) {
    return properties.containsKey(property);
  }

  public boolean contains(PropertyList<?> property) {
    return properties.containsKey(property);
  }

  public boolean contains(PropertyMap<?,?> property) {
    return properties.containsKey(property);
  }
}

usage.java

public class BpmnProperties {

  public final static PropertyList<EventDeclaration> EVENT_DECLARATIONS= new PropertyList<>("bpmn.eventDeclarations");
  public final static Property<Boolean> IS_FOR_COMPENSATION= new Property<>("bpmn.insForCompensation");
  
}


Properties properties = new Properties();
List<EventDeclaration> declarations = properties.get(EVENT_DECLARATIONS);
boolean isForCompensation = properties.get(IS_FOR_COMPENSATION);