Question

Anyone know what could be causing the following RUN TIME error in my Java program trying to access an Oracle database on a different Linux server?

java.lang.ClassCastException : com.sun.gjc.spi.jdbc40.CallableStatementWrapper40 cannot be cast to oracle.jdbc.OracleCallableStatement

I was following the discussion/example on page 4-14 to 4-15 in Oracle’s JDBC Developer Guide ( http://isu.ifmo.ru/docs/doc112/java.112/e10589.pdf ). I created something similar to that example and it worked fine. Then I started modifying it to get to the below code AND introduced GlassFish into the process, and now I get that error.

Here’s my Java code:

public List<Report> GetReports(String var1, String var1, String var3) throws Exception {
    Connection conn;
    CallableStatement cs;
    ResultSet rset;
    String out1; 

    Context context = new InitialContext();
    DataSource ds = (DataSource)context.lookup("jdbc/myPool");
    conn = ds.getConnection();

    cs = conn.prepareCall( "{call my_proc (?,?,?,?,?)}" );

    cs.setString(1, var1);
    cs.setString(2, var2);
    cs.setString(3, var3);

    cs.registerOutParameter(4, Types.VARCHAR);
    cs.registerOutParameter(5, OracleTypes.CURSOR);

    cs.execute();

    out1 = cs.getString(4); 

    List<Report> userReports = new ArrayList<Report>();

    rset = ((OracleCallableStatement)cs).getCursor(5);
    while ( rset.next() ) {
        Report report = new Report();
        report.col1 = rset.getString("myCol1");
        report.col2 = rset.getString("myCol2");
        userReports.add(report);
    }

    if ( rset != null ) {
        try { rset.close(); } catch ( Exception ex ) {}
        rset = null;
    }

    if ( conn != null ) {
        try { conn.close(); } catch ( Exception ex ) {}
        conn = null;
    }

return userReports;
}

Answer 1

There’s probably more than one way to solve this, but the following change to the above code works for me. Replace this statement:

rset = ((OracleCallableStatement)cs).getCursor(5);

with this statement:

rset = (ResultSet) cs.getObject(5);