JPA - Error preparing CallableStatement - Index 4 out of range but only have 3 params - sql-server

Question

I'm using Spring Data JPA 1.10.2 with com.microsoft.sqlserver's sqljdbc 4.2. I get the following error:
o.h.engine.jdbc.spi.SqlExceptionHelper : Error preparing CallableStatement [User.pTest]
com.microsoft.sqlserver.jdbc.SQLServerException: The index 4 is out of range.
My entity class is:
#Entity
#NamedStoredProcedureQuery(name = "User.getUser", procedureName = "User.pTest", parameters = {
#StoredProcedureParameter(mode = ParameterMode.OUT, name = "session", type = byte[].class),
#StoredProcedureParameter(mode = ParameterMode.IN, name = "name", type = String.class),
#StoredProcedureParameter(mode = ParameterMode.IN, name = "date", type = Date.class)
})
#Data //lombok
public class User {
// serves no purpose other than to meet
// JPA requirement
#Id
private Long id;
}
The repository code is
public interface UserRepository extends Repository<User, Long> {
#Procedure("User.pTest")
byte[] getUserSession(#Param("name") String name,
#Param("date") Date date
);
}
My test code is as follows and when I run it I get the error:
#Test
public void testGettingApxSession() {
Calendar cal = new GregorianCalendar(2016,6,5);
byte[] b = userRepository.getUserSession("myName", cal.getTime());
}
How do I resolve the error?
Update
Forgot to include the relevant part of the SQL Server stored proc:
ALTER procedure [User].[pTest]
#session varbinary(max) out
,#name nvarchar(max) = null
,#opt nvarchar(max) = null
,#date datetime
as
begin
set #session = CAST(N'<?xml version="1.0" encoding="UTF-16" ?><Session session = 45"'/>' as varbinary(max))
end

Answer 1

If you specify the nth parameter, Microsoft SQL Server driver requires that you also include the other parameters up to n. For example, let's say your procedure has five parameters (in this order) each having a default value of null:
param1 = null
param2 = null
param3 = null
param4 = null
param5 = null
You may only want to specify a value for param4. But if you do, you also must at least specify param1, param2, and param3 in the call to the stored procedure.
That may not seem too much of an issue. But if you have many default params and only need to specify say the 15th parameter, it will be quite tedious to also have to specify the other 14.
At least that's not fatal. But it is fatal in combination with the following Hibernate rule: Hibernate requires that each specified param is not null. But what if the procedure requires that only param3 or param4 have a value (but not both)? If you specify param4 to have a value, then you must include param3 (per MS driver) and you must give it a value (per Hibernate). So, you're sunk.
The only solutions are
Use a different driver such as jTDS (which has an issue on truncating >8000 bytes) OR
Write a wrapper procedure to just have only the needed params (e.g. param4) and let it call the procedure with five parameters.
Details of the exception in the OP
The Microsoft SQL Server driver has found (in the db metadata) four stored procedure parameters and returns the name and index of each. Then, the Hibernate / JPA code is building the CallableStatement.Via #NamedStoredProcedureonly three parameters have been defined. So, it builds something like pTest(?,?,?). But then Hibernate uses the metadata to say that Date should be in the fourth position which is out of range. The built pTest only has three parameters.