CREATE PROCEDURE dbo.spCheckPerson (
    @inXML XML,
    @outXML XML OUTPUT,
    @inDebug BIT = 0 )
AS
    --do sth

SET @outXML = '<person><name>Piotr</name></person>'

RETURN 0

import java.sql.Types;
import java.util.Map;

import javax.sql.DataSource;

import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.SqlOutParameter;
import org.springframework.jdbc.core.SqlParameter;
import org.springframework.jdbc.core.simple.SimpleJdbcCall;
import org.springframework.jdbc.support.xml.Jdbc4SqlXmlHandler;

public class PersonDAOImpl implements PersonDAO {

    private JdbcTemplate jdbcTemplate;
    private SimpleJdbcCall spCheckPerson;

    public PersonDAOImpl(DataSource dataSource) {
        jdbcTemplate = new JdbcTemplate(dataSource);
    }

    @Override
    public String checkPersonData(String personData) {
        Jdbc4SqlXmlHandler sqlXmlHandler = new Jdbc4SqlXmlHandler();
        spCheckPerson = new SimpleJdbcCall(jdbcTemplate)
                .withoutProcedureColumnMetaDataAccess()
                .withProcedureName("spCheckPerson")
                .declareParameters(new SqlParameter("inXML", Types.SQLXML))
                .declareParameters(new SqlOutParameter("outXML", Types.SQLXML));
        Map<String, Object> result = spCheckPerson.execute(sqlXmlHandler.newSqlXmlValue("<test>Test</test>"));
        return (String) result.get("outXML");
    }

}

SEVERE: Servlet.service() for servlet [SpringDispatcher] in context with path [/TestSpringProject] threw exception [Request processing failed; nested exception is java.lang.ClassCastException: com.microsoft.sqlserver.jdbc.SQLServerSQLXML cannot be cast to java.lang.String] with root cause
java.lang.ClassCastException: com.microsoft.sqlserver.jdbc.SQLServerSQLXML cannot be cast to java.lang.String
    at pl.test.dao.PersonDAOImpl.checkPersonData(PersonDAOImpl.java:32)
    at pl.test.controller.HomeController.listPerson(HomeController.java:20)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)