I have a shipment need a specified vehicle to deliver (not because of it has size constraint or tight time window).
How can I achieve this?
Many thanks
Try using the skill / required skill for this.
Skills are on vehicles and required skills on services, shipments and delivery.
I think that you can try to add a capacity dimension too.
See this exemple : https://github.com/graphhopper/jsprit/blob/master/jsprit-examples/src/main/java/com/graphhopper/jsprit/examples/MultipleProductsWithLoadConstraintExample.java
But try with the skills first ;).