Redeploying an app

[Mike Curwen]

Hi it's me again. This is still in regards to the Chapter 4 example of the BMP entity bean, from Sun's J2EE Developer's Guide.

As I mentioned in my other post on this topic, I found that I needed to run cloudscape's IJ tool so I could "delete from account;" before I re-ran my application.

I decided I'd modify the Account EJB so that it would not simply throw an uncaught expection. So here is the modified method:

   private void insertRow (String id, String firstName, String lastName,
                           double balance) throws SQLException {
          String insertStatement =
                "insert into account values ( ? , ? , ? , ? )";
          PreparedStatement prepStmt =
                con.prepareStatement(insertStatement);
          prepStmt.setString(1, id);
          prepStmt.setString(2, firstName);
          prepStmt.setString(3, lastName);
          prepStmt.setDouble(4, balance);
          try {
            prepStmt.executeUpdate();
            prepStmt.close();
          }
          catch(SQLException e) {
              System.err.println(e.toString());
          }
   }

The try catch block at the end is inserted by me. This works great now.

But I had a good deal of trouble gettting Sun's app server to "Update and Redeploy". In short, it doesn't work, or I'm perhaps expecting too much of it. I needed to completely remove the EJB From the Account app, and re-do the EJB Jar Wizard, resetting all the jdbc stuff, and the transaction support, etc..

Is there no way for the app server to realize that a recompile is necessary, since the source class files have changed? It seems to do this check, but poorly. Example: here is the output in the DOS window when I undeploy the app, and click "update and redeploy"

.........more stuff above......
Application Account has been undeployed
Class loadable save
Parse deployment descriptor as XML
No code generation required...
d:\j2sdkee1.2.1\repository\samadi\applications\Account9865669527i8Server.jar
Binding name:'java:comp/env/jdbc/AccountDB'
Application Account deployed.

But there is code generation required! How to get it to realize this is the problem.

[Amy Zeng]

hi, Mike, have you solved "update and redeploy' problem? Now it happened to me. i have not any idea about it.

[Mike Curwen]

see my response to your other post.

I eventually realized that 'update and redeploy' was broken, but there is a work-around. hopefully you are not like the 'unlucky' co-worker of mine.

[Amy Zeng]

Thanks, Mike,
I think i have same bad luck as your 'co-worker', every time I need to break every JAR and War, then close the depolytool, reopen it and refill Wizard that was missed after i close the tool. Now I am sick for the deploytool but i have to use it to finish my project, my group members have no problem to use it.
Thanks again.
Amy

[Peter den Haan]

Completely unrelated to your questiojn, but...

   private void insertRow (String id, String firstName, String lastName,
                           double balance) throws SQLException {
          String insertStatement =
                "insert into account values ( ? , ? , ? , ? )";
          PreparedStatement prepStmt =                con.prepareStatement(insertStatement);
          prepStmt.setString(1, id);
          prepStmt.setString(2, firstName);
          prepStmt.setString(3, lastName);
          prepStmt.setDouble(4, balance);
          try {
            prepStmt.executeUpdate();
            prepStmt.close();
          }
          catch(SQLException e) {
              System.err.println(e.toString());
          }
   }

In case of an exception, the statement will not be closed. Try

          try {
            prepStmt.executeUpdate();
          }
          catch(SQLException e) {
              System.err.println(e.toString());
          }
          finally {
            try { prepStmt.close(); } catch (Exception e) { }
          }
   }

Similarly, I don't know where your Connection is coming from but you should take care to close it in a finally clause. (I hope you're not grabbing a permanent connection for your bean -- that's what connection pools are for).
- Peter