DropDownPropertyConfig.java

  @Property(label="Select One Value",name="label", options={
      @PropertyOption(name="title1",value="value1"),
      @PropertyOption(name="title2",value="value2")
  },value="defaultvalue", description="Some Description")
  private static final String PROPERTY_SCHEDULER_DATASOURCE = "label";
  private String label;
  //And then
    @Activate
  protected void activate(final Map<String, Object> config) {
        this.lebel = PropertiesUtil.toString(config.get("label"), "some_default_value");

  }