Error reading XMLType column

Question

Hi All,
I know that this has been asked before but i've tried some of the recommendations and still doesn't work for me:(
I have table with a column of XMLType and it's related with a xmlschema registered in the db.I'm working with oracle 10g.
I'm trying to retrive the column value and create and xml file here's my code:
DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
m_Connection = DriverManager.getConnection("jdbc:oracle:oci8:@" +
sIP + ":" + sPort + ":" + sSchemaName,
sSchemaUsername, sSchemaPasswd);
OraclePreparedStatement s = (OraclePreparedStatement)m_Connection.prepareStatement(qryStr);
ResultSet rset = s.executeQuery(qryStr);
OracleResultSet orset = (OracleResultSet) rset;
while (orset.next()) {
XMLType xt = XMLType.createXML(orset.getOPAQUE(1));
Document dom = xt.getDOM();
return dom;
but i get this error:
java.sql.SQLException: Only LOB or thin Storage is supported in Thin XMLType
     at oracle.xdb.XMLType.processThin(XMLType.java:1979)
     at oracle.xdb.XMLType.<init>(XMLType.java:974)
     at oracle.xdb.XMLType.createXML(XMLType.java:525)
any ideas?
thanks
viki

Answer 1

Viki
This is not as elegant as we would like...
Basically here's the matrix
Storage                  Driver              DOM  Class
Object                    OCI                oracle.xdb.dom.XDBDocument + Lazy DOM
Object                    Thin                N/A - See workaround below
Text                       OCI                 oracle.xdb.dom.XDBDocument - Lazy DOM
Text                       Thin                oracle.xml.parser.v2.XMLDocumentHere is the code that demonstrates this
package com.oracle.st.xmldb.pm.examples;
import com.oracle.st.xmldb.pm.common.baseApp.BaseApplication;
import java.io.Reader;
import oracle.jdbc.OracleConnection;
import oracle.jdbc.OraclePreparedStatement;
import oracle.jdbc.OracleResultSet;
import oracle.sql.CLOB;
import oracle.xdb.XMLType;
import oracle.xml.parser.v2.DOMParser;
import org.xml.sax.XMLReader;
public class GetXMLType extends BaseApplication
   public void doSomething(String[] Args) throws Exception
     OraclePreparedStatement  statement = null;
     String statementText;
     statementText = "select object_value from " + getSettings("TargetTable") + " where rownum < 2";
     System.out.println("GetXMLType.doSomething : Driver Type = " + this.getDriver() + ". Statement = " + statementText);
     OracleResultSet resultSet = null;
     org.w3c.dom.Document  doc = null;
     XMLType xml;
     statement = (OraclePreparedStatement) getConnection().prepareStatement(statementText);
     resultSet = (OracleResultSet) statement.executeQuery();
     while (resultSet.next())
         xml = (XMLType) resultSet.getObject(1);
         doc = xml.getDOM();
         System.out.println("GetXMLType.doSomething : DOM = " + doc.getClass().getName());
         xml.close();
       resultSet.close();
       statement.close();
       getConnection().close();
  public static void main (String[] args)
    try
      GetXMLType example = new GetXMLType();
      example.initializeConnection();
      example.doSomething(args);
    catch (Exception e)
      e.printStackTrace();
}OCI Driver on XMLType with object persistance (OR Storage)
ConnectionProvider.establishConnection(): Connecting as SCOTT/TIGER@jdbc:oracle:oci8:@(description=(address=(host=localhost)(protocol=tcp)(port=1521))(connect_data=(service_name=ORA10GR2.xp.mark.drake.oracle.com)(server=DEDICATED)))
ConnectionProvider.establishConnection(): Database Connection Established
GetXMLType.doSomething : Driver Type = OCI. Statement = select object_value from PURCHASEORDER where rownum < 2
GetXMLType.doSomething : DOM = oracle.xdb.dom.XDBDocument
Process exited with exit code 0OCI Driver with on XMLType with Text Persistance.
ConnectionProvider.establishConnection(): Connecting as SCOTT/TIGER@jdbc:oracle:oci8:@(description=(address=(host=localhost)(protocol=tcp)(port=1521))(connect_data=(service_name=ORA10GR2.xp.mark.drake.oracle.com)(server=DEDICATED)))
ConnectionProvider.establishConnection(): Database Connection Established
GetXMLType.doSomething : Driver Type = OCI. Statement = select object_value from PURCHASEORDER_CLOB where rownum < 2
GetXMLType.doSomething : DOM = oracle.xdb.dom.XDBDocument
Process exited with exit code 0.Thin Driver on XMLType with object persistance (OR Storage)
ConnectionProvider.establishConnection(): Connecting as SCOTT/TIGER@jdbc:oracle:thin:@localhost:1521:ORA10GR2
ConnectionProvider.establishConnection(): Database Connection Established
GetXMLType.doSomething : Driver Type = Thin. Statement = select object_value from PURCHASEORDER where rownum < 2
java.sql.SQLException: Only LOB or String Storage is supported in Thin XMLType
     at oracle.xdb.XMLType.processThin(XMLType.java:2264)
     at oracle.xdb.XMLType.<init>(XMLType.java:1089)
     at oracle.xdb.XMLType.createXML(XMLType.java:583)
     at oracle.xdb.XMLType.createXML(XMLType.java:565)
     at oracle.xdb.XMLTypeFactory.create(XMLTypeFactory.java:73)
     at oracle.sql.OPAQUE.toClass(OPAQUE.java:376)
     at oracle.sql.OPAQUE.toJdbc(OPAQUE.java:318)
     at oracle.jdbc.driver.NamedTypeAccessor.getObject(NamedTypeAccessor.java:144)
     at oracle.jdbc.driver.NamedTypeAccessor.getObject(NamedTypeAccessor.java:100)
     at oracle.jdbc.driver.OracleResultSetImpl.getObject(OracleResultSetImpl.java:915)
     at com.oracle.st.xmldb.pm.examples.GetXMLType.doSomething(GetXMLType.java:73)
     at com.oracle.st.xmldb.pm.examples.GetXMLType.main(GetXMLType.java:89)
Process exited with exit code 0.Thin Driver on XMLType with Text persistance (CLOB Storage)
ConnectionProvider.establishConnection(): Connecting as SCOTT/TIGER@jdbc:oracle:thin:@localhost:1521:ORA10GR2
ConnectionProvider.establishConnection(): Database Connection Established
GetXMLType.doSomething : Driver Type = Thin. Statement = select object_value from PURCHASEORDER_CLOB where rownum < 2
GetXMLType.doSomething : DOM = oracle.xml.parser.v2.XMLDocument
Process exited with exit code 0You can get a DOM from an Object persisted XMLType via the Thin Driver using the following workaround
package com.oracle.st.xmldb.pm.examples;
import com.oracle.st.xmldb.pm.common.baseApp.BaseApplication;
import java.io.Reader;
import oracle.jdbc.OracleConnection;
import oracle.jdbc.OraclePreparedStatement;
import oracle.jdbc.OracleResultSet;
import oracle.sql.CLOB;
import oracle.xdb.XMLType;
import oracle.xml.parser.v2.DOMParser;
import org.xml.sax.XMLReader;
public class GetDOMFromCLOB extends BaseApplication
   public void doSomething(String[] Args) throws Exception
     OraclePreparedStatement  statement = null;
     String statementText;
     statementText = "select p.object_value.getClobVal() from " + getSetting("TargetTable") + " p where rownum < 2";
     System.out.println("GetXMLType.doSomething : Driver Type = " + this.getDriver() + ". Statement = " + statementText);
     OracleResultSet resultSet = null;
     org.w3c.dom.Document  doc = null;
     CLOB clob;
     statement = (OraclePreparedStatement) getConnection().prepareStatement(statementText);
     resultSet = (OracleResultSet) statement.executeQuery();
     while (resultSet.next())
        clob  = resultSet.getCLOB(1);
        DOMParser parser = new DOMParser();
        parser.parse(clob.getCharacterStream());
        doc = parser.getDocument();
        System.out.println("GetXMLType.doSomething : DOM = " + doc.getClass().getName());
       resultSet.close();
       statement.close();
       getConnection().close();
  public static void main (String[] args)
    try
      GetDOMFromCLOB example = new GetDOMFromCLOB();
      example.initializeConnection();
      example.doSomething(args);
    catch (Exception e)
      e.printStackTrace();
}which generates the following output...
ConnectionProvider.establishConnection(): Connecting as SCOTT/TIGER@jdbc:oracle:thin:@localhost:1521:ORA10GR2
ConnectionProvider.establishConnection(): Database Connection Established
GetXMLType.doSomething : Driver Type = Thin. Statement = select p.object_value.getClobVal() from PURCHASEORDER p where rownum < 2
GetXMLType.doSomething : DOM = oracle.xml.parser.v2.XMLDocument
Process exited with exit code 0.This works by creating a CLOB from the XMLType and then reparsing it to obtain a DOM on the client side... This is what happens under the covers when a Text persisted XMLType is processed using the Thin Driver.