jodd-json/src/main/java/jodd/json/JsonObject.java
public Double getDouble(final String key) {
		Number number = (Number) map.get(key);

		if (number == null) {
			return null;
		}
		if (number instanceof Double) {
			return (Double) number;
		}
		return number.doubleValue();
	}
public Double getDouble(final String key) {
		Number number = (Number) map.get(key);

		if (number == null) {
			return null;
		}
		if (number instanceof Double) {
			return (Double) number;
		}
		return number.doubleValue();
	}
Returns the double value with the specified key.