public ExpressionMeasurable(final String expression, final Unit<Q> unit) {
try {
this.expression = JexlUtil.newExpression(expression);
} catch (final Exception e) {
throw new IllegalArgumentException("Expression " + expression + " is not valid", e);
}
this.unit = unit;
}
@Override
public Double getValue() {
if (this.expression == null) {
return Double.NaN;
} else {
try {
return Double.valueOf(
JexlUtil.evaluateExpression(this.context, this.expression).toString());
} catch (final NullPointerException e) {
return 0.0;
}
}
}