Error "Failed to construct URI for OData request with request path" SAP Java VDM withQueryParameter - sap-cloud-sdk

Question

I have create a CAP VDM in java with SAP SDK 3.29.1.
In event handler #On read, i would like to pass the input filters to the VDM.
Es.
#On(event = CdsService.EVENT_READ, entity = "XXXX")
public void readXXX(CdsReadEventContext context) throws ODataException {
final String filter = context.getParameterInfo().getQueryParameter("$filter");
final List<XXXXX> dati = new DefaultXXXService().getAllXXXX().select().withQueryParameter("$filter", filter).executeRequest(dest);
}
When run the query in the log i get the error:
"Failed to construct URI for OData request with request path ..."
"Illegal character in query at index 95. ...."
But the path and filter is right for the call, can you help me?
In the old version sdk i used:
FilterExpression filtriFrontEnd =FilterExpressionConverter.convertTo(queryRequest.getQueryExpression());
final List<XXXX> area = new DefaultXXXXService().getAllXXX().filter(new UncheckedFilterExpression<>(filtriFrontEnd)).select().execute(new ErpConfigContext("XXX"));
Thank you.

Answer 1

When run the query in the log i get the error: "Failed to construct URI for OData request with request path ..." "Illegal character in query at index 95. ...."
Can you check whether the following works for you..?
import com.sap.cloud.sdk.datamodel.odata.client.request.ODataUriFactory;
final String filter = context.getParameterInfo().getQueryParameter("$filter");
final String encodedFilter = ODataUriFactory.encodeQuery(filter);
final List<XXXXX> dati = new DefaultXXXService().getAllXXXX().select().withQueryParameter("$filter", encodedFilter ).executeRequest(dest);
Please let me know, as this could be an issue that needs to be addressed.

Answer 2

The method contract of withQueryParameter which explicitly warns about this API usage:
Using this function to bypass fluent helper method calls can lead to unsupported response handling. There is no contract on the order or priority of parameters added to the query.
Instead please use the filter function directly. There should be an entity field for the postal code, the code should look similar to this:
new DefaultXXXService()
.getAllXXXX()
.filter(Entity.POSTAL_CODE.eq("16100"))
If this is not feasible in your use case I suggest to build this filter expression manually as you did before and apply encoding to it as Alex pointed out in his answer.