Terse Systems

Rewrote the blog in Ruby on Rails. Thanks, Aaron. Comments are now back online, after I had to shut them off due to comment spam. The blog now runs all comments through Akismet.

I don’t really have much to say about Ruby or Rails that hasn’t been said by many people before; I just have my experience of it, which I think is more valuable than the technical minutiae.

I think the biggest strength of Rails (and Ruby for that matter) isn’t the framework. It’s the community.

The framework solves the problem it’s supposed to solve. The community is all aligned around an agile mindset. As such, there’s not the “There’s more than one way to do it” philosophy of Perl. Instead, the philosophy is “How do we make this simple, flexible and easy to build on?” When you’re working along the same assumptions, Rails makes it very, very easy to do what you want. The community supports that, not just with tutorials, but with podcasts, screencasts, and books.

However, if you’re doing something that isn’t in that set of assumptions – if you have legacy data or non-Railsy database schema and associations – you’re off the map. In a way, this was good because I got to figure out how Rails really works, but it was certainly a dunk in cold water after having so much help available.

This has been something I’ve wanted to do for years. Gave up some features for it; no automatic java syntax highlighting, no full text search, and no filtering by categories. But I’ve got the bones, and I can work on the flesh later. Now, sleep.

I wrote my blog from the ground up. It seemed like an interesting technical exercise at the time. Now I have actual content and people who comment, I’m in a much better position to appreciate the benefits and drawbacks.

Plus: I know exactly what’s going on. It does exactly what I want.
Minus: If something doesn’t work, I can’t draw on a user community to fix it for me.
Plus: I can use the blog as a proving ground for new technology.
Minus: Spammers also learn new technology.

I thought I was very clever for writing my own blog, because spammers were oriented against WordPress and Blogger and wouldn’t bother with as small a target as one custom written blog. I failed to take into account that spammer technology would advance to the point where they would figure out how to act like users and hit a comment button without regard to the back end technology.

I tried cleaning out the spam manually. This is like trying to stop the tide with a bucket. The problem is to come up with a comment submission scheme that spammers cannot hack, and that I need to think about.

In the meantime, I’ve disabled comments altogether. And in lieu of deleting the comments by hand, I’ve used this problem as an opportunity to think about how to do ad-hoc deletes from the repository.

Hence the BeanshellAdminService. This little beauty runs in the AdminServer, and allows me to run beanshell scripts on the server. It’s so convenient that I can’t believe I didn’t think of it years ago. For development, it lets you do just about anything.

I’ve uploaded it to the usual place. This is useful for your normal services as well. You can override the admin servlet to set your own parameters for the interpreter, so if there’s a function that you want to pull in or some parameters that you want to set, you can set them with an anonymous subclass. Best to do that from another module though, so you don’t inadvertently deploy scriptable code to production…

Hokay. I have a workable configuration environment now.

There’s one master Spring file, and two subsiduary files that contain environment specific properties.

The main file is below (minus the data source):

<bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
  <property name="exposeTransactionAwareSessionFactory" value="false"/>
  <property name="dataSource" ref="dataSource"/>
  <property name="mappingResources">


&lt;list&gt;
  &lt;value&gt;com/tersesystems/blog/dao/hibernate/PostImpl.hbm.xml&lt;/value&gt;
  &lt;value&gt;com/tersesystems/blog/dao/hibernate/CommentImpl.hbm.xml&lt;/value&gt;
  &lt;value&gt;com/tersesystems/blog/dao/hibernate/CategoryImpl.hbm.xml&lt;/value&gt;
  &lt;value&gt;com/tersesystems/blog/dao/hibernate/MemberImpl.hbm.xml&lt;/value&gt;
  &lt;value&gt;com/tersesystems/blog/dao/hibernate/MediaImpl.hbm.xml&lt;/value&gt;
  &lt;value&gt;org/appfuse/model/Role.hbm.xml&lt;/value&gt;
  &lt;value&gt;org/appfuse/model/User.hbm.xml&lt;/value&gt;
  &lt;value&gt;org/appfuse/model/UserCookie.hbm.xml&lt;/value&gt;
&lt;/list&gt;


  </property>      

  <property name=”hibernateProperties” ref=”hibernatePropertiesBean”/>    

</bean>

Note the references to the hibernatePropertiesBean. This is an instance of PropertiesFactoryBean that will be defined in the environment Spring file.

The JTA Spring file is defined below:

<bean id="hibernatePropertiesBean" class="org.springframework.beans.factory.config.PropertiesFactoryBean">
  <property name="properties">


&lt;props&gt;
  &lt;prop key="hibernate.dialect"&gt;${hibernate.dialect}&lt;/prop&gt;
  &lt;prop key="hibernate.cache.use_query_cache"&gt;${hibernate.cache.use_query_cache}&lt;/prop&gt;         
  &lt;prop key="hibernate.cache.use_second_level_cache"&gt;${hibernate.cache.use_second_level_cache}&lt;/prop&gt;        
  &lt;prop key="hibernate.cache.provider_class"&gt;${hibernate.cache.provider_class}&lt;/prop&gt; 
  &lt;prop key="hibernate.current_session_context_class"&gt;${hibernate.current_session_context_class}&lt;/prop&gt;
  &lt;prop key="hibernate.show_sql"&gt;${hibernate.show_sql}&lt;/prop&gt;        
  &lt;prop key="hibernate.connection.release_mode"&gt;auto&lt;/prop&gt;
  &lt;prop key="hibernate.query.substitutions"&gt;${hibernate.query.substitutions}&lt;/prop&gt;          
  &lt;!-- Must be enabled for JTA transactions... --&gt;    
  &lt;prop key="hibernate.transaction.manager_lookup_class"&gt;${hibernate.transaction.manager.lookup}&lt;/prop&gt;  
&lt;/props&gt;


  </property>  

</bean>

and the JDBC one is defined likewise. Note that we can’t have even an empty property existing for hibernate.transaction.manager.lookup here.

<bean id="hibernatePropertiesBean" class="org.springframework.beans.factory.config.PropertiesFactoryBean">
  <property name="properties">


&lt;props&gt;
  &lt;prop key="hibernate.dialect"&gt;${hibernate.dialect}&lt;/prop&gt;
  &lt;prop key="hibernate.cache.use_query_cache"&gt;${hibernate.cache.use_query_cache}&lt;/prop&gt;         
  &lt;prop key="hibernate.cache.use_second_level_cache"&gt;${hibernate.cache.use_second_level_cache}&lt;/prop&gt;        
  &lt;prop key="hibernate.cache.provider_class"&gt;${hibernate.cache.provider_class}&lt;/prop&gt; 
  &lt;prop key="hibernate.current_session_context_class"&gt;${hibernate.current_session_context_class}&lt;/prop&gt;
  &lt;prop key="hibernate.show_sql"&gt;${hibernate.show_sql}&lt;/prop&gt;
  &lt;prop key="hibernate.connection.release_mode"&gt;auto&lt;/prop&gt;
  &lt;prop key="hibernate.query.substitutions"&gt;${hibernate.query.substitutions}&lt;/prop&gt;   
  &lt;!-- Do not allow transaction.manager.lookup to be defined here. --&gt;       
&lt;/props&gt;


  </property>  

</bean>

This doesn’t include the changes to the transaction manager or the like, but it gets the point across.

Then, since the servlet isn’t around to do it for me, I have to define a hibernate session “in-house” for integration tests:

public void onSetUp() throws Exception
{  



super.onSetUp();

ApplicationContext context = applicationContext;
sessionFactory = (SessionFactory) context.getBean("sessionFactory");
sessionFactory.getCurrentSession().beginTransaction();


}

@Override
protected void onTearDown() throws Exception
{ 



if (transaction != null) 
{
    transaction.commit();
}

super.onTearDown();


}

And now all my integration tests work! Yay!

I used Carlos Sanchez’s post as a guide, and have been looking at Alef’s Configuration Management with Spring for more information.

Still surprised at how much work it is to override properties in Spring. As far as I know, there’s no way you can explicitly say “I’m scribbling over another bean definition” now, apart from where you’ve explicitly set it up that way with PropertyOverrideConfigurer. Among other things, I don’t see any way that you can change a bean’s defined class once it’s set up, which is something you can do in Nucleus right off the bat.

Still, it works, and I should be thankful I can do integration testing at all. Now to go look at Webwork forms.

So. In the previous post, I talked about integration testing. An integration test runs through Webwork, Hibernate and Spring and expects a certain amount of scaffolding to work right.

I’ve been having a very tough time getting that scaffolding to work right. Part of the problem is that there is no mutually agreed pattern for handling Hibernate sessions.

When I am using the Spring design pattern (OpenSessionInView), the Spring integration tests work fine. But that pattern doesn’t allow lazy loading unless you do some fancy acrobatics. And if you write your own code to handle Hibernate sessions… things don’t work so well.

Specifically, I wrote a transaction filter and a session per request filter:

Session session = sessionFactory.getCurrentSession();
try
{


// Joins the existing JTA transaction, or creates one.
session.beginTransaction();
//boolean rollback = true;
try
{
    filterChain.doFilter(request, response);
    // commented out because JTA transaction seems to
    // do this for us...
    //rollback = false;
} finally
{
    //if (rollback)
    //    tx.rollback();
    //else        
    //    tx.commit();
}


} finally
{

session.close();


}

and then just did a very simple DAO pattern that called sessionFactory.getCurrentSession() from inside the DAO. Now, if I were using Hibernate 3.0, then getCurrentSession would require a JTA transaction to be in place, and I wouldn’t be able to run an integration test unless I found a replacement J2EE container. However, I’m using Hibernate 3.1. Hibernate 3.1 does not require an existing JTA transaction to be in place for getCurrentSession(). So I should be fine, right?

Wrong. It turns out that Spring wraps all calls to the sessionFactory object and calls its own utility class instead. Every time you call sessionFactory.getCurrentSession(), Spring calls SessionFactoryUtils.doGetSession() for you. And doGetSession() checks to see if there’s a JTA transaction, and if there isn’t one… it doesn’t let you call getCurrentSession.

In fairness, this has been noted as bug SPR-1354 and fixed in CVS. But that does me no good.

So what I tried to do is setup the integration tests with a different Spring configuration. Instead of setting up the sessionFactory with JTATransactionManager and OrionTransactionLookup, I’d extract all the relevant beans and properties, and have applicationContext-jta.xml and applicationContext-jdbc.xml files only containing the relevant transaction config. The sort of thing you could do in ATG in five minutes using a Nucleus layer.

This… sort of works.

However, I’m having trouble setting up the Hibernate properties. This breaks because when I’m in the app server, I need to set transaction.manager_lookup_class to OrionTransactionLookup. But I need it not to exist for the integration testing. I can define a property with a null value, but Hibernate still sees that the key exists and complains about it.

About the only solution I can think of is to have the props map abstracted out to a properties file and see if I can swap in different properties files. (EDIT: Fixed, see here for details.)

The interception framework should be optional – it should let Hibernate fail on its own. And HibernateTemplate/OpenSessionInView stuff gets around a problem that, as far as I can tell, doesn’t exist.

I don’t get it. I thought this was supposed to be easy.

EDIT: okay, NOW I get it.

EDIT: Also see here for an excellent review of Spring’s “integration” with Hibernate.

So far I’ve been focusing on Webwork. However, I’ve also been trying more automated testing again. My previous effort didn’t work so well, as I spent more time writing the mockobjects library than writing the unit tests, but I was happy to give it another try using TestNG.

Unit tests work fine for me, but I’m still not fascinated by them.

Things got more interesting when I discovered the integration testing classes in Spring. I found that the Spring integration test classes were built on top of JUnit, and didn’t seem to support TestNG. So I switched, and it was so worth it.

Integration testing with Spring is awesome. I can write some code, write an integration test, then run through the test until I’m sure I know what’s going on. This really helps when parsing posts. A raw post goes through several different parsers to do things like colorize Java code, bleep swearwords and escape HTML characters, so there are many opportunities to parse things in the wrong order or not at all.

Here’s a sample:

public class DisplayPostActionTest extends


    AbstractDependencyInjectionSpringContextTests {
@Override
protected String[] getConfigLocations() {
    return fakeDatabasePaths;
}

private static String[] fakeDatabasePaths = {
    "classpath*:/applicationContext-test.xml", "classpath*:/applicationContext.xml", 
};

DisplayPostAction displayPostAction;

/* (non-Javadoc)
 * @see org.springframework.test.AbstractDependencyInjectionSpringContextTests#onSetUp()
 */
@Override
protected void onSetUp() throws Exception {
    ApplicationContext context = applicationContext;        
    displayPostAction = (DisplayPostAction) context.getBean("displayPostAction");
}

public void testExecute() {        
    try {
        displayPostAction.setPostId("43");
        String returnValue = displayPostAction.execute();
        assertNotNull(returnValue);

        assertTrue(Action.SUCCESS.equals(returnValue));

        Post post = displayPostAction.getPost();
        assertNotNull(post);            
    } catch (Exception e) {
        e.printStackTrace();
        fail();
    }
}


}

I have a question. Hibernate for the most part does exactly what I expect it to, and all is good. However, the elements() function doesn’t seem to be working as it should. I suspect my mapping may be off.

Is this legal?

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC


    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"&gt;


<hibernate-mapping package=”com.tersesystems.blog.dao.hibernate”>

  <!–   



CREATE TABLE blog_category (
category        varchar2(40)    NOT NULL,
PRIMARY KEY(category)
);    


  –>

  <class name=”CategoryImpl” table=”BLOG_CATEGORY”>  



&lt;id name="name" column="CATEGORY"&gt;      
&lt;/id&gt;


  </class>

</hibernate-mapping>

and

public class CategoryImpl implements Category
{


private String mName;

/**
 * @return Returns the name.
 */
public String getName() {
    return mName;
}

/**
 * @param pName The name to set.
 */
public void setName(String pName) {
    mName = pName;
}

public String toString() {
    return "CategoryImpl: " + mName;
}


}

Because when I do this query:

String queryString = "from PostImpl as post where :category in elements(post.categories) "


         + " and post.state = :state order by post.date desc";


Query query = session.createQuery(queryString);

query = query.setParameter(“category”, pCategory);
query = query.setInteger(“state”, PostState.PUBLISH.asCode());
List posts = (List) query.list();

I get this:

2005-12-31 13:48:46,046 INFO [org.hibernate.event.def.DefaultLoadEventListener] - <Error performing load command>
org.hibernate.ObjectNotFoundException: No row with the given identifier exists: [com.tersesystems.blog.dao.hibernate.CategoryImpl#
Programming, Programming]


    at org.hibernate.ObjectNotFoundException.throwIfNull(ObjectNotFoundException.java:27)
    at org.hibernate.event.def.DefaultLoadEventListener.load(DefaultLoadEventListener.java:118)
    at org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:75)
    at org.hibernate.impl.SessionImpl.immediateLoad(SessionImpl.java:643)
    at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:59)
    at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:84)
    at org.hibernate.proxy.CGLIBLazyInitializer.intercept(CGLIBLazyInitializer.java:134)
    at com.tersesystems.blog.dao.hibernate.CategoryImpl$$EnhancerByCGLIB$$6d6de9a8.toString(&lt;generated&gt;)
    at java.text.MessageFormat.subformat(MessageFormat.java:1237)
    at java.text.MessageFormat.format(MessageFormat.java:828)
    at java.text.Format.format(Format.java:133)
    at java.text.MessageFormat.format(MessageFormat.java:804)
    at com.tersesystems.blog.dao.hibernate.HibernatePostDAO.findPublishedByCategory(HibernatePostDAO.java:192)
    at com.tersesystems.blog.action.DisplayPostsAction.execute(DisplayPostsAction.java:130)</pre></div>



It’s disconcerting.  I’m not even sure what the error message means.
          
        
      
      
  

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