While I agree that the client code should have no knowledge of what
driver it is using, somehow the JDBC driver classes do need to
eventually find their way to the client machine. Since J2EE doesn't
specify the process by which client files get to the client machine (and
for good reason), there are a lot of ways to do it.
>From you description, it looks like the weblogic launcher will
automatically download the JDBC driver. I stand corrected :-) I wonder
how they deal with licensing issues... I doubt they let just anyone
download their jDrivers :-) And why didn't they make a launcher that
downloads *all* the necessary classes so you can have a zero install
footprint on the client machine? Looking at their docs, it looks like
ClientDeployer wants the whole ear file to be installed on the client.
Yuck. But I'll agree, downloading some classes is probably better than
no classes.
Orion is not so friendly. You've got to package everything up in the
client jar file, including the interface classes of the ejbs you want to
use. The good news is that in this process it's simple to put the
minimum subset of classes into the client package :-) And dynamically
downloading the class files is slow anyways :-) :-) :-)
Jeff
>-----Original Message-----
>From: Tom Mitchell [mailto:[EMAIL PROTECTED]]
>Sent: Tuesday, January 30, 2001 6:29 PM
>To: Orion-Interest
>Subject: Re: R: R: frustrated - jdbc: No suitable driver
>
>
>Jeff,
>
>I disagree. Part of the benefit of a DataSource is that it
>can abstract
>the actual driver or database being used. If I can ask a
>DataSource for
>a database connection and not have to care about which client-side
>driver to load, and (less practically), even what rdbms i am using.
>That way, the app server can change databases, drivers, even vendors
>without its clients being aware.
>
>I experienced this issue porting an app from WebLogic. I used the same
>schema and sql with SQL Server and Postgres on WebLogic. My client
>application (which both queried and populated the database) never
>changed. It just got a Context from the app server, gfot a DataSource
>by name, then got plain old JDBC Connections from there. No JDBC
>drivers at all.
>
>I think that is a useful layer.
>
>PS: I have unsubscribed from the list - if you would like to continue
>the discussion, please reply to my personal address.
>
>Thanks for your thoughts.
>
>I appreciate your point of view, I just disagree with it.
>
>Jeff Schnitzer wrote:
>>
>> If the client is going to use the JDBC driver, it must be
>able to load
>> the class(es). This means you need to package the driver with the
>> client application. I'm puzzled by your comments about clients not
>> needing to care about drivers - are these classes just going to
>> materialize out of thin air? I suppose in theory the server could do
>> something with http classloading, but why bother with the extra
>> complexity, security considerations, and licensing issues? You know
>> you're going to need the classes anyways, package them with
>the client.
>>
>> Jeff
>>
>> >-----Original Message-----
>> >From: Tom Mitchell [mailto:[EMAIL PROTECTED]]
>> >Sent: Tuesday, January 30, 2001 9:08 AM
>> >To: Orion-Interest
>> >Subject: Re: R: R: frustrated - jdbc: No suitable driver
>> >
>> >
>> >Again, thanks for your replies.
>> >
>> >What is curious to me is that the driver performs fine
>within a jsp. I
>> >look up loc with no problem.
>> >
>> >It only has a problem from a client application. And, it
>does not seem
>> >like a client to a DataSource should ever have to care
>about drivers -
>> >that is the container's job in my opinion.
>> >
>> > <data-source
>> > class="com.evermind.sql.ConnectionDataSource"
>> > name="SomeDatasource"
>> > location="loc"
>> > xa-location="jdbc/xa/SomeXADS"
>> > ejb-location="ejb/weather"
>> > schema="database-schemas/postgresql.xml"
>> > connection-driver="org.postgresql.Driver"
>> > username="tom"
>> > password="tR16/4"
>> > url="jdbc:postgresql://192.168.1.5:5432/weather"
>> > inactivity-timeout="30"
>> > />
>> >
>> >Any more ideas?
>> >
>> >DeVincentiis Giustino wrote:
>> >>
>> >> Sorry, the message "No suitable driver" probably means a
>> >problem with jdbc
>> >> driver.
>> >> So if you have into the data-sources.xml the definition:
>> >>
>> >> <data-source
>> >> class="com.evermind.sql.DriverManagerDataSource"
>> >> name="Hypersonic"
>> >> location="jdbc/HypersonicCoreDS"
>> >> xa-location="jdbc/xa/HypersonicXADS"
>> >> ejb-location="jdbc/HypersonicDS"
>> >> connection-driver="org.hsql.jdbcDriver"
>> >> username="sa"
>> >> password=""
>> >> url="jdbc:HypersonicSQL:./database/defaultdb"
>> >> inactivity-timeout="30"
>> >> />
>> >>
>> >> you should lookup "jdbc/HypersonicDS", and you should
>have the driver
>> >> classes in your /orion/lib directory.
>> >>
>> >> Giustino
>> >>
>> >> -----Messaggio originale-----
>> >> Da: Tom Mitchell [mailto:[EMAIL PROTECTED]]
>> >> Inviato: martedì 30 gennaio 2001 12.24
>> >> A: Orion-Interest
>> >> Oggetto: Re: R: frustrated - jdbc: No suitable driver
>> >>
>> >> Thanks for the reply. That is exactly how I am initializing
>> >the context
>> >> in my client application:
>> >>
>> >> Hashtable ht = new Hashtable();
>> >> ht.put(Context.INITIAL_CONTEXT_FACTORY,
>> >> "com.evermind.server.ApplicationClientInitialContextFactory");
>> >> ht.put(Context.PROVIDER_URL, "ormi://192.168.1.3");
>> >> ht.put(Context.SECURITY_PRINCIPAL, "someUser");
>> >> ht.put(Context.SECURITY_CREDENTIALS, "secret");
>> >> // Obtain connection
>> >> InitialContext ctx = new InitialContext(ht);
>> >>
>> >> DeVincentiis Giustino wrote:
>> >> >
>> >> > Try initializing the context this way:
>> >> > ...
>> >> > Properties props = new Properties();
>> >> >
>> >>
>> >props.setProperty("java.naming.factory.initial","com.evermind.s
>> >erver.Applica
>> >> > tionClientInitialContextFactory");
>> >> > props.setProperty("java.naming.provider.url",
>> >> "ormi://localhost/app-name");
>> >> > props.setProperty("java.naming.security.principal", "admin");
>> >> > props.setProperty("java.naming.security.credentials", "123");
>> >> > InitialContext ctx = new InitialContext(props);
>> >> > ...
>> >> >
>> >> > Giustino De Vincentiis
>> >> >
>> >> > -----Messaggio originale-----
>> >> > Da: Tom Mitchell [mailto:[EMAIL PROTECTED]]
>> >> > Inviato: martedì 30 gennaio 2001 1.23
>> >> > A: Orion-Interest
>> >> > Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED]
>> >> > Oggetto: frustrated - jdbc: No suitable driver
>> >> >
>> >> > Hi All,
>> >> >
>> >> > I am used to WebLogic, so please pardon my ignorance...
>> >> >
>> >> > I am trying to get my WebLogic application to run on Orion.
>> >> >
>> >> > I have a DataSource set up to PostgreSql. It seems OK
>because this
>> >> > Orion JSP works fine:
>> >> >
>> >> > InitialContext ctx = new InitialContext();
>> >> > out.print("<br>Context: " + ctx);
>> >> > DataSource ds = (DataSource) ctx.lookup("jdbc/DefaultDS");
>> >> > Connection conn = ds.getConnection();
>> >> >
>> >> > // Create query and get results
>> >> > Statement stmt = conn.createStatement();
>> >> > ResultSet rs = stmt.executeQuery("select count(*) FROM
>> >> > weathersnapshots");
>> >> >
>> >> > // List results
>> >> > while ( rs.next() ) {
>> >> > out.println( "<br>" + rs.getObject(1) + "<br>");
>> >> > }
>> >> >
>> >> > // Close connection - important!
>> >> > conn.close();
>> >> >
>> >> > This runs fine and gives me the count of rows in the table.
>> >> >
>> >> > When I try to get the standalone client to the same
>> >DataSource to run, I
>> >> > get this:
>> >> >
>> >> > Context: javax.naming.InitialContext@316e52
>> >> > Exception in thread "main" java.sql.SQLException: No
>> >suitable driver
>> >> > at java.sql.DriverManager.getConnection(Unknown Source)
>> >> > at java.sql.DriverManager.getConnection(Unknown Source)
>> >> > at
>> >com.evermind.sql.DriverManagerDataSource.getConnection(JAX)
>> >> > at Test.main(Test.java:18)
>> >> >
>> >> > No errors appear on the server's console. I can not
>> >imagine why I would
>> >> > want to have a DB driver's jar in my client's classpath
>> >(ALTHOUGH I HAVE
>> >> > TRIED THAT).
>> >> >
>> >> > I have an application-client.xml:
>> >> >
>> >> > <application-client>
>> >> > </application-client>
>> >> >
>> >> > I have scoured the list archives and can not find the solution.
>> >> >
>> >> > Remember, within the container, it runs fine. It is the
>> >standalone app
>> >> > that does not work.
>> >> >
>> >> > Using:
>> >> > Orion 1.4.5
>> >> > JDK 1.3
>> >> > Win2K
>> >> >
>> >> > Thanks in advance.
>> >> >
>> >> > --
>> >> > Tom Mitchell
>> >> > [EMAIL PROTECTED]
>> >> > Very Current Stoneham, MA Weather
>> >> > http://www.tom.org
>> >>
>> >> --
>> >> Tom Mitchell
>> >> [EMAIL PROTECTED]
>> >> Very Current Stoneham, MA Weather
>> >> http://www.tom.org
>> >
>> >--
>> >Tom Mitchell
>> >[EMAIL PROTECTED]
>> >Very Current Stoneham, MA Weather
>> >http://www.tom.org
>> >
>> >
>
>--
>Tom Mitchell
>[EMAIL PROTECTED]
>Very Current Stoneham, MA Weather
>http://www.tom.org
>
>
