CachedRowSet using DataSource

Question

Has anyone else had this problem.
This piece of code works fine:
RowSet rs = new JdbcRowSetImpl();
rs.setDataSourceName("java:/comp/env/jdbc/ChemNetDB");
rs.setCommand("Select * from TBL_DISPLAY_FIELDS where DEFAULT_FIELD=1");
rs.execute();
this one doesn't
RowSet rs = new CachedRowSetImpl();
rs.setDataSourceName("java:/comp/env/jdbc/ChemNetDB");
rs.setCommand("Select * from TBL_DISPLAY_FIELDS where DEFAULT_FIELD=1");
rs.execute();
It give this error:
java.sql.SQLException: The url cannot be null
     java.sql.DriverManager.getConnection(DriverManager.java:489)
     java.sql.DriverManager.getConnection(DriverManager.java:171)
     com.sun.rowset.CachedRowSetImpl.execute(CachedRowSetImpl.java:735)
     com.sun.rowset.CachedRowSetImpl.execute(CachedRowSetImpl.java:1360)
     org.apache.jsp.Search_jsp._jspService(Search_jsp.java:98)
Is this a bug. I haven't seen anyone else have this problem. I'm using tomcat 5.
Thanks,
Peter

Answer 1

I've got the same probs you do (using the datasource name doesn't do any good at all, keeps throwing a "URL cannot be null" exception. For interest sake, this is using the latest postgresql driver, compiled under 1.5).
Here's a workaround that seems to work fine, however:
          //get the initial context, which is used to authenticate the user against the database
          DataSource ds = null;
          if (ctx == null) {
               try {
                    ctx = new InitialContext();
                    ds = (DataSource)ctx.lookup("java:comp/env/jdbc/myDS");
               } catch (Exception e) {
                    throw new ServletException(e);
          //authenticate the user
          try {
               CachedRowSetImpl rs = new CachedRowSetImpl();
               rs.setCommand("select count(1) from some_table");
               rs.execute(ds.getConnection());
          } catch (Exception e) {
               throw new ServletException(e);
The juice here, of course, is that by passing the connection into the rs.execute command I bypass whatever bug the CachedRowSetImpl has, and I get to reuse my pooled database connections