Spring JPA Stored Procedure with a null value?
<p>I have a stored procedure and it's being called from a JpaRepository implementation as such</p>

<pre><code>@Repository
public interface DataMartRepo extends JpaRepository&lt;DataMartDAO, String&gt; {

    @Procedure(procedureName = "dbo.txn_ETL")
    public void txnETL(
        @Param("txId") String txId,
        @Param("inId") String inId,
        @Param("proc") String proc,
        @Param("qtys") String qtys);
</code></pre>

<p>Now, this works fine, expect for when "proc" is a null value, in which case it throws an exception:</p>

<pre><code>SEVERE: Servlet.service() for servlet [dispatcher] in context with path [/Authenticator] 
threw exception [Request processing failed; nested exception is org.springframework.orm.jpa.JpaSystemException: 
    Error calling CallableStatement.getMoreResults; nested exception is org.hibernate.exception.GenericJDBCException: 
    Error calling CallableStatement.getMoreResults] with root cause
com.microsoft.sqlserver.jdbc.SQLServerException: The value is not set for the parameter number 3.
at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(SQLServerException.java:190)
at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.buildParamTypeDefinitions(SQLServerPreparedStatement.java:260)
at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.buildPreparedStrings(SQLServerPreparedStatement.java:219)
at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.doPrepExec(SQLServerPreparedStatement.java:612)
at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.doExecutePreparedStatement(SQLServerPreparedStatement.java:400)
[...]
</code></pre>

<p>How do I deal with null values? Setting all Strings to "" doesn't offer null inserts.</p>