Tag: Tomcat 6

I started working through Hightower’s tutorial available as a free pdf from theserverside.com and am having a few problems. I will record fixes as I encounter problems. Note that Struts version 1.3.10 has changes whereas the Hightower tutorial, Jakarta-Struts Live, is for version 1.1. I am also working with Tomcat 6 (apache-tomcat-6.0.18) , ant (apache-ant-1.7.1) and Java 6 (jdk1.6.0_04) . The fixes I am describing are what I am getting to work on the above-described configuration. I am not saying that the tutorial is wrong for Struts version 1.1.

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CHAPTER 1
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On page 4 where he is discussing setting up on a Tomcat 5 server, note that Tomcat 6 has changed the previous directory structure $TOMCAT_HOME/common/lib/ to just $TOMCAT_HOME/lib/ … there is no longer a common directory present.

On page 17 where we are writing our first action form, note that the class ActionError is no longer available in Struts 1.3.10 and one must use ActionMessage instead. So, in the code for the UserRegistrationForm class, comment out ‘import org.apache.struts.action.ActionError;’ and add ‘import org.apache.struts.action.ActionMessage;’ … Also later on, swap out ActionError in the validate method with ActionMessage.
On page 20 where we are writing our first input view (jsp page), we ignore any of the changes to the web.xml file with regard to the additions. Also, still in #2 on that page, we do the directives in the jsp differently. Instead of
‘<%@ taglib uri=”/tags/struts-html” prefix=”html”%>’
use the following namespaces for the uri, like this:
‘<%@ taglib uri=”http://struts.apache.org/tags-html” prefix=”html”%>’
‘<%@ taglib uri=”http://struts.apache.org/tags-bean” prefix=”bean”%>’
I spent a lot of time diddling around with this and from what I read in the google searches, a lot of other people have wasted time too. This is because the tld’s are packaged in the struts-taglib-1.3.10.jar file which is in the lib directory in WEB-INF in the struts-blank app. The servlet api has now made it easy to find the tlds in the jar file provided they were packaged properly (see the Struts site for instructions for a proper configuration or look at the jar file in the distribution). Note that including taglib information in web.xml will result in the application not being able to find the tlds.

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ON PAGE 27 UPDATE THE ACTION TO HANDLE FORM AND CANCEL BUTTONS
Since version 1.2.8 the ‘cancellable=”true”‘ statement must be placed in the action tag path=”/userRegistration” in struts-config.xml. Otherwise, hitting the cancel button results in exception.

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MOVING ON TO USING DATABASE
As an FYI Hightower notes that, although he is using an HSQL database, “You
should be able to use any database that has a suitable JDBC driver.” … which should be true but in this example, the name of the table, USER, isn’t going to work on an Oracle database because USER is a reserved word. Hence I changed the name of the table to STRUTSUSER since I was using an Oracle database.

On page 30 of the tutorial the code uses the method getDataSource which is not present on the Action class in version 1.3.10. I found a discussion at JavaRanch and will use a DAO which in turn will use JDBC to get a connection to the database. This is good for separation of concerns and is immediately valuable for unit testing the DAO independent of the rest of the application (always a good thing!). Nevetheless, this makes the datasource-relevant information, which was added to struts-config.xml, irrelevant and for me the entire Struts 1.X version somewhat dysfunctional and even more reason to use Struts 2.x version or, its evolved form (Spring… :). Having just coded the DAO and using raw JDBC for database manipulation, I am reminded of how easy Spring makes database manipulations because it saves you from TCFTC (Try-Catch-Finally-Try-Catch).

Oh, and yes, at this point forget about letting Struts handle any database connection pooling …
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PAGE 32: EXCEPTION HANDLING
Now that we’re not even using Struts to manage database connections, it’s not going to see any sql exceptions either(we’re catching sql exceptions in our DAO) so we need to find another way to worry about exception handling by Struts.

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PAGE 35: DISPLAY AN OBJECT WITH STRUTS TAGS

This works as described in the tutorial but remember to use the uri discussed above for the bean tag.

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PAGE 37: USING LOGIC TAGS TO ITERATE OVER USERS

As discussed above, the logic tags directive would look like this:
<%@ taglib uri=”http://struts.apache.org/tags-logic” prefix=”logic”%>

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CHAPTER 2: TESTING STRUTS
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Having suffered through the early versions of EJB I am reminded of one of the reasons why developers created their own lightweight frameworks, like Struts and Spring – to enable unit testing the POJOs (the domain-object model) without the container obstructing the tests. For those not familiar with the history of that era, I recommend Bruce Tate’s “Don’t Make Me Eat The Elephant Again.”
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PAGE 59: Using StrutsTestCase (Mock Mode) Step-by-Step

I will be using strutstest-2.1.4.jar