Name: rmT116609 Date: 07/28/2004


FULL PRODUCT VERSION :
java version "1.4.2"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2-b28)
Java HotSpot(TM) Client VM (build 1.4.2-b28, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]

A DESCRIPTION OF THE PROBLEM :
When accessing an Access database throught JDBC with the ODBC bridge, the type of one of the column returned by ResultSetMetaData.getColumnClass() is returned as being java.lang.Short but the returned values (ResultSet.getObject()) are java.lang.Integer. This fails to comply with the Java SDK AP specification which states:

"Returns the fully-qualified name of the Java class whose instances are manufactured if the method ResultSet.getObject is called to retrieve a value from the column"

(http://java.sun.com/j2se/1.4.2/docs/api/java/sql/ResultSetMetaData.html#getColumnClassName(int))

This happens when the Access database use tables with Number/Integer (not Long Integer) Access data type.

The problem is also reproducible with J2SE 1.5.0-beta.


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
  To reproduce the problem, run the example below with the test.mdb file in the same directory. Unfortunately I just noticed I can't attached the mdb file. So here is how to create it (you can contact me if problems with reproducing):
- Run Access
- Create a new database named test.mdb (same directory as the java class to run)
- Add a new table named "Content"
- Create a column "FOO" of type Number/Long Integer
- Create a column "BAR" of type Number/Integer
- fill with some values.


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
I'm expecting:
expected type: java.lang.Short
actual type: class java.lang.Short
check Java SDK spec: true



ACTUAL -
The result I get is:
expected type: java.lang.Short
actual type: class java.lang.Integer
check Java SDK spec: false


ERROR MESSAGES/STACK TRACES THAT OCCUR :
This can of course produce ClassCastException if you rely on that information and cast the result in the expected type.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.sql.*;

public class WrongType {
    // CJO 11/03
    public static void main(String[] args)
        throws Exception {
        Class clazz = Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        java.sql.Driver driver = (java.sql.Driver)clazz.newInstance();
        DriverManager.registerDriver(driver);
        Connection connection = DriverManager.getConnection("jdbc:odbc:Driver={Microsoft Access Driver (*.mdb)};DBQ=test.mdb", null, null);
        PreparedStatement statement = connection.prepareStatement("select BAR from Content",
                                                          ResultSet.TYPE_SCROLL_INSENSITIVE,
                                                          ResultSet.CONCUR_READ_ONLY);
        ResultSet resultSet = statement.executeQuery();
        ResultSetMetaData metadata = resultSet.getMetaData();
        String expectedClassName = metadata.getColumnClassName(1);
        Class expectedClass = Class.forName(expectedClassName);
        System.out.println("expected type: "+expectedClassName);
        resultSet.next();
        Class actualClass = resultSet.getObject(1).getClass();
        System.out.println("actual type: "+actualClass);
        System.out.println("check Java SDK spec: "+expectedClass.isAssignableFrom(actualClass));
    }
}
---------- END SOURCE ----------


(Incident Review ID: 227939)
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